First, THANK YOU VERY MUCH for taking the time, spending the money & doing all of the 'heavy lifting' of testing these cells (that I was sooo excited about!) I'm more than a little disappointed that the cells varied by so much? Clearly, 2 cells came from a single batch, and the other (2) came from another. They varied enough that I wondered if 2 of the cells were from say 'version A' and the other 2 came from a more recent & improved lot. That being said: * I probably would've used a lower gauge wire to reduce losses (say 6 AWG or even a 4 AWG)? * I may've tried to do a .2C test, but- really I'm being a nitpicker, and, the wiring mentioned above would've been less of an issue, but... * I thought each cell was limited to 2.5v, so I was surprised to see 2.2v as the bottom? Asking? * Would it have helped to parallel the cells for a day or so- for the BMS & preventing the need for a bottom balance? * Do you think it might've performed slightly better (275 -280AH) if you had bottom balanced? Great test, great review & THANK YOU 1,000 times!!! I genuinely appreciate your efforts. Noted: another gentleman purchased 16 cells for a garage solar power project and he only was able to get @ 250AH or so. Perhaps they are slightly less powerful and they DO have limitations (none that will disturb me using them..) But, they still have a TON of stored power & the chemistry lasts for so many cycles!!! Dave
Its the role of the BMS to handle balancing for you. Having the cells connected to a bms for a day should give you the same result as connecting them parallel - they should get balanced. And a BMS is safer since it wil reduce/regulate the balancing current.
* Thanks!! :) * The read/black cables coming off the battery were 4 AWG. The black cable from the shunt to the inverter was 1/0 AWG as I already had a piece with ring terminals crimped on. * One thing I find interesting about the prismatic LiFePO4 batteries I've looked at is the capacity is usually given at a 1C discharge. I find that hard to believe, but I haven't tried a 1C test to see what happens. With this in mind, I think a 0.28C test is close enough to 0.2C commonly used by NMC chemistries. Lower amps may have resulted in another Ah or two, not sure. * The spec sheet for these batteries gave 2.5V as the low cutoff. The BMS was set for 2.2V. I can't change it for this particular BMS and wanted to leave it go to see what would happen (if the BMS would shut off). The voltage drop at that point in the discharge curve is so steep that the extra between 2.228V and 2.50V didn't make much of a difference. * Yes! I do think paralleling beforehand would have helped. I will be testing this later this week to see if there is any difference. I will report back my findings. I don't think the iCharger balanced long enough even though I had it set to "slow balance".
@@LithiumSolar I hope that you understand that I'm NOT questioning you in a 'snarky' way, I'm really trying to learn more (and, I'm more of a NOOB!) while being 'clear' instead of loose. Thanks (again!!!) for buying & testing these- I so appreciate all of your efforts! I was planning on using (2) Bluetooth programmable BMS' recommended by Will Prowse & paralleling them on arrival, discharging to a lower state of charge, balancing- charge & do a .2C rate test. .28C is so darn close- it thought it was higher (my bad!) Either way, 271AH is purdy darn close & still an exceptional value. I DO wish you had received 'matched' cells by lot as well as charge profile & resistance but at that price- it may be too much to ask! Hahaha
@@hubertnnn I think that Daly BMS' only charge at the very top of the charge cycle, and, often needs several charge cycles to balance the cells. When installed, the cell voltage variance was too large for it to even work. The resistors are pretty small on most BMS' that I've ever seen. With such a flat discharge curve, the amount of voltage in each cell can be pretty large -especially in 280AH prismatic cells!
@@DCGULL01 being snarky didn't even cross my mind... Out of all the comments, yours was the one I pinned lol. I am not an expert and am here to learn too. One reason I make these videos is I love reading through the comments, ideas, hearing what others are doing, etc. I do agree, 271Ah is still fantastic - I guess I just expected to see the full 280Ah after what I've been reading from others. I'll be ordering my next batch from Basen (seems to be who most are recommending) and getting 16 at once. Hopefully those will be matched. I love the Daly BMS for small builds and testing, but I'll be using a Batrium on my final production setup :)
You got 97% of the rated capacity, and your breaker and negative cable were generating some heat. The 300 mV drop from the terminals to the shunt is also about 97% of the voltage, so the cells seem to be pretty close to 280Ah. And for that price, seems like you did well!
The losses in cables, breaker etc do not affect Ah-measurement. The shunt measures the current going through the circuit and it does not matter where the energy is dissipated, whether in the actual load or elsewhere.
@@mcg6762 Errm. No. I don't believe that is accurate. Any losses between the terminal and the shunt (which is where my comment clearly identified the 300mV loss) is dissipated as heat before it any measurment by the shunt. That 300mV X (the amps) equals power lost at any moment, and power lost over a period of time is lost energy. See the First Law of Thermodynamics--the Law of Conservation of Energy for more info.
@@daveduncan2748 Ah is different from Wh. The shunt measures current. All current must go through the shunt, regardless of where the voltage is dropped.
@@The2000redrocket If you have more than one shunt in the same series circuit they would all measure the same current. Basic circuit theory. The current is the same everywhere for a straight series circuit.
Many users are buying from this resller called XUBA and specifcally asking for AMY as there rep. I bought 32 all same qr style code and tested to full 280 ah. Running a 16s2p setup on a 48V mpp solar LV5048
@@alharrison3255 You are correct, elsewhere in the comments here, I have linked to the new company she started with her husband. Good service, good prices, and she doesn't exaggerate (aka lie) to sell you a product. At the time I purchased my cells, she worked at Xuba, now she has her own company at szluyuan.en.alibaba.com/
I've watched a few of these for the 280 ah and most get the 280 or close with all the wiring and such 271 seems close enough for me. You do great work thanks.
Wow! a most excellent video. Great production. Lighting, audio quality, and your narration. Just easy to watch, and appreciate your thoroughness. Going to watch more of your channel. Thank you!
I've been debating selling my 16s NMC pack and dropping $10k or so on a massive bank of these. I don't like that they don't even have the rated capacity out of the box though. Thanks for digging into them!
As an Australian, planning out batteries is a challenge. Throwing money at the problem, yeah I can get battle-born's. But that's AU $1300, not including shipping. Local suppliers appear to charge similar prices for what the US market would call the B-grade to Battle-born.
Not sure about your datasheet, but Off Grid Garage found that his 'manual' said to let the cells sit for an hour after charging before starting the test or something like that.
Great Job ! I’ve gotten 280Ah 3.2v Lithium Phosphate from AliExpress about 108.00 each and I asked if they were grade A or B and the seller wrote back Grade A being made as they were written ! I have not tested
You commented on the heat build up and forgive my answer I did not spend a lot of time on research but is probably lost amps due to this. Reducing the Amount of Power Lost as Heat in Wires On the previous page we saw that transmitting serious amounts of power down an electrical wire at 230 Volts would result in incredible amounts of heat being lost in the wire. What can be done to help? The power lost in an electrical wire is governed by the equation Power = Current squared x resistance. So to reduce the power loss, we just have to reduce either the current or the resistance. To reduce the resistance of a wire, we need to make it larger. There will be more metal to carry the current, so the resistance will be lower. Unfortunately, we would soon end up with an enormous wire, which would be hideously expensive. The better solution is to reduce the current. This has the advantage that if we can reduce the current by ten times, we will reduce the power loss by a hundred times! (Remember, power loss in wires is equal to current squared times resistance.) How do we reduce the current and still transmit the same power? Simply increase the voltage. Remember, Power = Voltage x Current. If we increase the voltage by 10 times, we reduce the current by 10 times, and this reduces the power lost in the wire by 100 times. So let's go back to our small town using 23MW of power. If we tried to transmit that power to the town at 230 volts down wires with a resistance of 1 Ohm, it would have needed 100,000 Amps of current, resulting in 10,000MW of power loss. However, what if we used a High Voltage power line running at 132,000 volts? (132kV) This would reduce the current required to just 174 Amps. Transmitting this down a wire with a resistance of 1 Ohm would result in just 0.03MW of power lost as heat. To provide 23MW to our town, we would have to send 23.03MW down the power line. The longer a wire is, the higher its resistance will be. If a piece of wire has a resistance of 1 Ohm, then a piece of wire twice as long will have twice the resistance, i.e. 2 Ohms. This means that longer wires lose more power due to resistance, so the further you transmit power, the more you lose as heat. Clearly, you would be mad to try and send electricity a long distance at low voltage. You would use a high enough voltage to reduce power losses to an acceptable level, and that's exactly what happens in real life. But how do you change the voltage? As I said earlier, the two ways of generating electricity are direct current or DC, and alternating current or AC. The reason why we use AC in our homes is that it is easy to change the voltage, whereas with DC it would be very difficult.
@@LithiumSolar It can take sitting at that level for quite a long time to balance them as you increase the number of cells. With 4 you might not notice as much, but when you have 8 or 16 cells in parallel they won't really be balanced. I believe it is due to resistance.
Note that the straight forward method of connecting cells in parallel isn't the best. Reversed blocks of two is optimal, according to this author: www.solar-electric.com/lib/wind-sun/Iota_balanced_charging.pdf
I'm on the more patriotic side of things generally, but what the heck is up with all these EVERYTHING FROM CHINA IS TERRIBLE comments? And why do they generally seem to be sock puppet/troll accounts? Anyway... like others have said, thanks for (potentially) taking the hit and trying these batteries out. I've also been looking into off-grid options, and this info is extremely helpful and interesting.
I wouldn't say everything from China is junk, but when you order from a non-branded store that may not care about developing a good reputation with buyers you may end up with junk that nobody else wanted mis-marketed. This happens with such frequency that it isn't surprising that they were under capacity or mis-matched. What was surprising was that they were as close as they were. China can, and does make high-end products. They just come with much higher price tags and are usually sold by "reputable vendors" By that phrase I don't mean something like Rolex, or Nike. I mean a vendor that cares about fostering a good reputation. Think of it like this. The DMV doesn't really care about the reputation. You can spend well over an hour waiting there and it is considered normal. Starbucks does care. If you spent an hour there it is because after they got your drink made for you in about 5 minutes, they provided an atmosphere that you wanted to stay at. The same situation happens with e-commerce stores. Some spend a great deal of time fostering an atmosphere and trust. Others don't. Alibaba is like E-bay, with less buyer protections. Sometimes you get lucky. I've gotten lucky before. Sometimes, you don't get lucky.
Per the spec sheet from Eve, two are 2019 manufacture, and two are 2020 manufacturing date. Lower volume places frequently have stock sitting on the shelf a while, all of mine from a different vendor were manufactured in the same batch in the second half of 2020. Depending on the state of charge, sitting on the shelf for extended periods of time can lower capacity and lifespan. I suspect what you received was just two older cells, and everything passed all the manufacturing tests at the time, rather than grade b cells. I am sure they are not matched cells, which is different from grade a cells. It is actually quite difficult and time consuming to match cells, since the most commonly used measurement device for doing so clearly states it is not accurate above 100 amp hour cells.
That is a lot of eneregy storage and charge cycles for the money! What I don't like is the 6mm lug screws and the few threads that actually thread into the aluminum lugs. I built a battery using 240 ah cells purchased directly from Shenzen RJ Energy. One of the lugs stripped out even though I am very careful when tightening, but I was able to tap a larger screw into it and salvage the cell. I built a custom insulated boz with a silicon pad heater in it so it stays warm in cold weather. I have used this battery in my RV for 2 years now and it has worked perfectly with 400 w of charging PV's on the roof. I have never run the battery out when boondocking for weeks on end in the summer and up to one week even in late October in NE Washingon. The 280 ah cells you have are about half the cost of the 240 ah's I bought in 2018. They are a great value if you are capable of building it yourself. I think the fragile lugs make it best for stationary installs like a remore solar cabin , and less desirable for vibration uses like an RV. I check my lugs all the time and so far so good, but I think its just weak for high vibration uses.
Thanks for the review. I just ordered 4 280Ah cells from an eBay seller for about $170/cell, so not as good of a deal as yours... I’m just hoping they are matched, new cells, as they were advertised! This makes such a nice, compact, high capacity battery. Even at what I paid, it will be cheaper per usable amp hour than purchasing AGM batteries (considering 80% DOD for the LiFePO4 and 50% for the AGM). Thanks again for the review/capacity test!
It's true Battleborn is kinda overly priced. But it's a battery with a dedicated BMS - a finished product and these are just raw cells. And they give a warranty, but you get nothing like that with these cells, no one knows what to expect in long term usage.
@@cenchloraadums3143 A BMS module for a100ah battery bank cost $30.00. Four 100ah lifepo4 cells cost $180.00. Less than 1/4 the cost of battleborn. Even grade b batteries last more than 5 years. Spending $1000.00 on a 100ah battleborn battery is stupid, stupid, stupid.
@@drneedles7093 There are BMS modules even for 15 $. But if you go for sophisticated, yet reliable BMS, then you have to pay at least 50 $ and for reliable 100Ah cells need at least 300 $ even in China. So it won't be as cheap as you say, but let's say 500 - 600 $ including the battery case, costs of shipping and everything else. Anyway, you're right that 1000$ for a 100Ah battery is insane. And that's how most of products are priced in a place where people are like "oh it's dirt cheap, just xxx hundred bucks" and pay what would be a small mortgage where these products are actually manufactured. Lol
Off Grid Garage has been running heaps of tests with these 280AH LFP. I think he has ordered from Shenzhen Basen and they seem to have a small factory. Alibaba has tabs with company profile stuff. There may be other larger factories. Merit Sun has a YT video and they have a very advanced facililty. You have all these people dissing Chinese batteries but the tech says the Chinese are the leaders. You have to sort of figure out who the supplier is, whether they produce the cells or resell, stuff like that. To me this pricing is 'for real' and I love LFP so this is good. There was an article last week on pack prices for LFP at $100 a kwh. It all fits together. See if you can find a factory or a supplier and get comfortable with them. These cells are OK but I'd rather have fresher and from a matched batch. There's a long way to go with this stuff.
@@dansmith6990 Basically with unmatched cells, the lowest capacity cell is the max capacity of your pack. Some cells are also "runners", meaning that they change voltage rapidly just before full or empty, thus cutting a little off the top or bottom of the complete pack as well. Most packs of 280AH cells I have seen get from 250AH to 270AH due to these mismatches.
Part of the capacity loss would probably have been the wire used...When you first start the test, if the wire gets warm, its telling you that the gauge is not low enough and you have a bottleneck. When that occurs you are wasting energy in heat. Bigger wire (2 gauge) and retest. I also would never keep draining those cells past 2.5 volts, as there is little to no energy left after that point, and you are stressing the cell by doing this.
Thanks for the review. Such cells seem good and powerful, I even used them for welding directly. They have the or near the stated capacity. What we should research is their life-cycles. This is the only way to see if they are viable or not. You can find cells apparently with excellent specs that do even beyond the specs in initial tests but they quickly drop capacity after only a few full discharges. I've seen this in some cheap and apparently very good Li-Ion 26650s. I don't have the means to do an efficient cycle test on high capacity LiFePO4s. I doubt they get anywhere near the stated cycles.
I should add that when I got them, I hooked 18 of them in parallel and used my iCharger x8 to do a 1s charge to 3.65vdc. it took about 3-4 days, lol. it was awesome though.
@@tariqalmutairi1403 actually, rack batteries are so cheap now I’d buy them so I have a warranty & a professional looking installation. I saw 48v 100ah rack batteries for $1150 recently.
Dude, fantastic test ! Yes in the industry we're using automatic expensive equipment to cycle cells for test, but the test seriously boils down to what you have done - GREAT ! IF you are planing on using prismatic cells long term I would only suggest to provide a box that applies pressure to prevent cell swelling, but I think this is redundant since you seem to know what you are doing !
Question for you. I have heard that if it was stored for a while then it needs to be cycled a couple times to pull full capacity. Does this seem to be true?
These cells do seem to settle down to more consistent results after a couple of higher rate charge and discharge cycles, but as someone already explained, they also need to be cycled every 6 months when stored. The QR codes indicate that two of the cells were manufactured before December of 2019, and likely sat on a shelf without being cycled.
I suspect you are losing at least 3-5% of the battery power from Cables, BMS and Circuit breaker. I always try to double the ampacity of any device that passes the full current to the output. So in your case you would need bigger cables that are designed to handle at least 160 amps, probably 2 ga to 0/0 ga for that run length at that voltage. The BMS should be 150-200 amps rated. And at least a 150 amp fast trip circuit breaker. All these together should reduce your losses to heat generation in the components by up to 50 watts. If you did a direct capacity test on the battery you would likely see just over rated capacity, with no hardware in between. Keep up the good work, and Merry Christmas :)
Thanks so much for classroom technical data on these batteries. I currently have 2 200ah AGM batteries. They charge up great and fast (no complaints) I just have 70 (max) of only one battery for usage. I live full time in my van and after 1 year full time I’m ready 4 a change. I just can’t afford 2 Battleborn type lithium. Thanks 4 great post and channel. Look forward to more videos on this subject.
I love the way how you concetrate the right infos in your video and focus. Well done ! I wish every youtuber would do that. I am waiting for my cells coming from China in a few weeks and i gonna build myself a 24 200ah solar battery pack for my camping van. I am looking for how to test my cells the right way so i know what i got for my money.
This is like those "bargain" bags of apples where there is always exactly one in five that are bruised or mushy. They start with good and bad separate, then carefully mix a "tolerable" level of bad with the good. And hope the buyer believes it's randome.
Because I had a red cable with 2 lugs crimped on already and didn't want to cut it in half for the breaker. This was a test setup. It's best to use a double-pole breaker in DC battery installations.
Good test. I wouldn’t be cut up about about 96.4% of the rated capacity since by your own admission there were heat losses (resistances) in your circuit that happen before the current shunt. Well done though and thanks for a good review.
Didn't find anyone mention the numbers, but if you add in the line losses, you'll be closer than than 271ah mark. Still not crossing the 280ah barrier though. In future, if possible, for a testing rig, try shorter cables to reduce line losses?
Nice test and clean setup. Clearly resistance losses don't affect amp hour testing, they become part of the load and only reduce watt hours measured. The accuracy of the amp-hour measurement (including shunt, shunt voltage measurement and time accumulation accuracy) would need to be verified to validate the overall amp hour accuracy. These cells could be within spec and the result error (-2.9%) within instrumental accuracy. Batrium mentions 1% typical accuracy for the shunt component alone and "typical" isn't a worst case guaranteed spec, plus this must be added to the inaccuracy of the measurement subsystem. Not a bad result.
Sometimes I do this test in reverse to see how much I can put back in as you can't get out what you can't put in plus you get to see how efficient they charge, Cheers
I do the same as we’ll also be accounting for any losses to heat the wiring with the fill method. For true output, the draw method is more correct for identifying the energy available, but the circuit modifies the cell capacity with losses.
Great test with lots of important details...this kind of videos are actually rare. I think these cells have been used for at least several hundred cycles. If they're within volumetric and gravimetric energy densities of LiFePO4 chemistry, that should be the reason for lower capacity. Even discharging at 280A (1C) they should give over 90% of rated capacity. QR codes with no battery capacity are suspicious. These cells last thousands of cycles so they're refurbished (blue protective film re-wrapped, QR code + top black plastic film reattached - no big deal) and resold as brandnew or grade B cells depending on their condition. Finally, wire losses would only matter if you measure the voltage at the load. If the volt terminals of wattmeter are connected to battery terminals it measures total energy, including that dissipates at wires. However, power loss at aluminum bus bars (if there's any) may still left uncounted.
Likely the two manufactured in 2019 sat on a shelf without being cycled every 6 months like the manufacturer recommends. I wouldn't suspect used cells, much more likely improper storage conditions. The cells will very quickly degrade if stored fully charged or fully discharged, and must be cycled every 6 months of storage. Recommend state of charge for storage is 20 to 50%.
JFYI - for common metric thread sizes (M2 - M24+) you don't have to mention thread pitch.. it's not as complicated as the imperial system. Only in rare cases the thread pitch differs from the standard and it usually involves custom applications (say optical instrument optical path threads) or some designer wants to make sure that a certain grade bolt is being used (car seats for example need hardened bolts in my car and thus come with a non standard M10 thread pitch of 1.25 mm instead of 1.5 mm).
The aluminum canning is connected to positive. Would you build a pack like your present with an additional isolation between the cells for RV DIY battery builds. Thanks for your opinion Bob
Yes, I would put a spacer between the cells in a permanent installation. I wouldn't rely on the plastic wrapping alone, especially in an installation where vibration is present.
I purchased 16 pcs of 3.2V LiFePo4 cells on AE, Ogreen Lifepo4 cell Store, store number 5729174 The cells were rated minimum 180Ah. The best I could get from a 8s2p configuration after connecting the highest capacity cell with the lowest capacity cell in parallel was 240Ah which is 120Ah per cell. The cells internal resistance is a lot higher than specified.
Oh my god. U look just like my grandpa Smith. 40’s. When I was 5or6. I am now 83. I have less hair then u. He died of an enlarged heart. I am a 22 year survivor of 5 heart bypass. Just subscribed.
Thanks for the video. At first, I thought it was going to turn out bad when they didn't quite match in terms of build. But the results aren't too bad. Definitely didn't scare me away from ordering some.
Can you do an update on this brand of cells? The video is about 4 months old are they holding up? I am thinking of buying but endurance is my concern on Chinese batteries, thanks
Great video, question: can I lay the cell side way? Will it leak or effect performance? I am building a power box and laying side way give me more room to play with , thanks
It's generally accepted that the prismatic batteries can be placed in any orientation other than upside down. You should consult the manufacturer's specifications though for the specific cell you have.
I'm currently devouring as much info as I can in advance of building a solar system, and I have gleaned elsewhere that it is wise to discharge these batteries first, in order to do a "bottom balance" which sets the baseline, and then test them. If you need any information along those lines, then can I recommend Will Prowse and his excellent set of instructional videos, I think that he was weaned on battery acid with a digital dessert!
Well done. Do you think two 12v configurations could be wired in parallel to work with an existing 12v system? Looking to replace a set of 12v AGM batteries.
Yes, you could wire two 12V in parallel. You will need 2 BMS that way though. I would first wire the cells in groupings of two (parallel) then wire those in series such that you only need one BMS (4s2p). As for replacing the AGM batteries - you will need to check that the device supports LiFePO4 batteries to prevent over charging/discharging.
@@patrickmchargue7122 newer models of the Daly BMS like he used have low temperature cut off, but you have to ask for it when ordering. Newer models can also be purchased with Bluetooth and USB ports for monitoring and changing parameters, but again, you must specify when ordering.
Great content, thanks for making these videos. I have the same X6 charger but can't find a cable for the cell monitoring (the white wires with the alligator clips). Can you provide a source to where you got yours? Thanks
Thanks for test. I have same cells from Alibaba(different seller) and I did test capacity with two different metering devices and my numbers came very close to 270 AH as well. If you divide 270AH to 280Ah the percentage of capacity would be %96. They state that the cells are grade A and brand new but if you look at EVE specification booklet(or PDF) and look at Fig 3 "cycle performance", the 96% capacity means that the cells have around 750 cycles on them. secondly I contacted EVE company to read the cell specification from barcode(incuding production date) but they denied and said if you don't buy from them directly, they would not read the code. When I asked the seller on Alibaba they did not provide me an exact date and just said it is 2020 production. That may explain why they changed the barcode type on some of your cells from production date/line of assembly/serial info to just EVE 280AH maybe to stay out of trouble. Now with my test result confirmed, I am pretty sure the cells are not grade A and used because of 96% capacity and the EVE company is selling on Alibaba directly but prices are almost twice as these. With prices around 120/cell ,I would say it may still work easily another 2000 cycles to get to 80% capacity so it may still worth trying but I would not trust these building a huge power bank like off-grid etc.
Cell QR codes changed in December of 2019. He received two cells manufactured before December of 2019, and two manufactured in 2020. The manufacturer clearly states that the cells should be cycled every 6 months in storage. They should also be stored between 20 and 50% state of charge. Likely these just sat on the shelf somewhere for a while.
@@john_in_phoenix The problem is that you can not verify if the info on those QR codes unless you buy them directly from EVE for much higher price. So something is off here. Having all 4 cells down to 96% of capacity in my opinion is more consistent to have specific number of cycles on them. If the loss of capacity was due to sitting on shelf and 2 of them are 2019 and 2 are 2020 we may see different numbers of capacity loss.
@@VEMNEM1 At least some of the information is easy to verify by just looking at the spec sheet. The ones with the old style QR code were manufactured before 12/22/2019. The ones with the new style QR codes were manufactured AFTER that date, and indeed will tell you the exact date of manufacture (on the sticker). You can get the "decoder" spec sheet for some (but not all) of the QR fields here: diysolarforum.com/resources/eve-lf280n.139/
Bottom Balance along with Top Balance and you will get much more energy. The one cell shut down the BMS while other cells had energy remaining. Good job though ! Thanks
It's the shunt from a Batrium BMS www.batrium.com/ It's not designed to be used this way though. I wrote my own custom code to do this. The tablet is a Samsung Galaxy Tab A running Grafana.
@@RandomTechJunkie It's NodeJS. I started with this github.com/Batrium/WatchMonUdpListener and pretty much rewrote it to fit my needs (such as a MySQL database, multiple Batriums on the same network, etc).
I think it would have been better to parallel top balance, then disconnect the charge and and let them soak as a group for 24 hrs. There’s a very good chance that even with the best BMS eventually the mismatch of most of these “280” ah cells will be too much for the BMS’s tiny balance resistors. I highly recommend the newer Heltec capacitive type “active equalizer” (balancer) to be used WITH your chosen BMS. Also, avoid running groups (series) of 12 to get higher voltage. If you need 24 volts build a 24 volt battery and BMS/equalizer.
Hi, thanks for great info. I have a comment about the M6 screws, though, In order to use the full depth of the inside thread and compensate for different thickness of bus bars, I recommend to take longer M6 screw, cut the head off and then fully screw it in as a post. Then use M6 washer/nut to tighten the bar to specification. Just a thought. Cheers.
Threaded studs and flanged nuts seem to be the best option for these cells. Apparently it's really easy to damage the threading as it's an aluminium terminal
@@w3bb0y Some vendors just started offering studs welded in rather than tapped holes. Probably costs extra, but that is an option that I would pay for, the aluminum is too easy to strip when trying to get a nice tight connection.
The 2019 spec sheet for the cells says (in testing section), that the capacity is only valid for one month after leaving the factory and before 5 cycles (charge/discharge cycles). This leaves an obvious out for the manufacturer to say it meets spec, you just tested wrong. I think everyone would be happier if they just rated it realistically (like Leishen rates an almost identical cell as 272AH). I have 16 of the Eve cells, and I am running capacity tests now.
does having them connected in parallel automatically balance them? (assuming the voltage is near identical when you connect them so it doesn't blowup) nvm I see several studies that say they should be left in parallel a few days before building a battery
0:12... is that each or for all 4 ? After your initial power test I would have recharged the batteries and done the test for a 2nd time to verify the results since you dis not start with depleted batteries with the first test.
Can you run a charging test to see how well it balances without the balancer? Likely they should charge pretty evenly, mostly the BMS should not be needed?
Thanks for this! You mention that your circuit breaker was getting warm, but I notice that the shunt is not measuring any power consumption by the breaker itself, as it is wired after the breaker. You might want to change this, and install the shunt as the first item from the battery, that way you'll be recording any power that the breaker consumes. Perhaps that is where your missing amp-hours escaped to... Cheers.
Question please, why do you take the battery all the way until the BMS shuts off to get the current? I would think a 12v battery pack you will need the 12 v to power devices as many items wont work below about 11.5 to 12 volts so then I would think when the total battery pack is at the 12 v or 11.5 v then thats the real amount of current that is real? As you really don't want to take the battery in to DOD even these are LIFEPO4 and can handle doing a DOD point I would stop at the 11.5 or 11.75 volts?
The low cutoff point defined by the manufacturer is 2.5V per cell or 10.0V for the 4s battery. The whole point of this video was to test the capacity of the batteries, and you can't do that with out a full depth of discharge ;) I would agree, in typical use scenarios, don't do a 100% depth of discharge and it will last longer.
Great breakdown ... one thing has me ... Building a powerwall is straight forward, I'd like to see an Automatic Transfer Switch for Grid to Battery power, I have a 200amp service, but the only ATS I can find seem to be 100amp, should I take the feed-in from the grid and split it one to a sub-panel powered by the ATS, separating out the circuits I want to power from Batteries?
Thanks. This is just a testing setup here. The breaker will work on either the positive or negative. In a DC application such as this, a double-pole should be used so both polarities pass through.
any idea why you only for 271 ah ? do you think its based around the condition of the batteries or inaccuracies and loses through the equipment used or maybe a little all of the above?
you do a gr8 job explaining things, thanks. the 3.65v might be in the specs as the max voltage, but it is not recommended as a voltage to cycle to at every charge cycle. at this voltage you wil severely reduce your overall lifespan of the battery. 3.5v is a better max voltage to use.
Of course. You can order and have it shipped pretty much anywhere. If the supplier doesn't ship to your country, you can use a 3rd party freight forwarder. I've used both methods.
First, THANK YOU VERY MUCH for taking the time, spending the money & doing all of the 'heavy lifting' of testing these cells (that I was sooo excited about!) I'm more than a little disappointed that the cells varied by so much? Clearly, 2 cells came from a single batch, and the other (2) came from another. They varied enough that I wondered if 2 of the cells were from say 'version A' and the other 2 came from a more recent & improved lot. That being said:
* I probably would've used a lower gauge wire to reduce losses (say 6 AWG or even a 4 AWG)?
* I may've tried to do a .2C test, but- really I'm being a nitpicker, and, the wiring mentioned above would've been less of an issue, but...
* I thought each cell was limited to 2.5v, so I was surprised to see 2.2v as the bottom? Asking?
* Would it have helped to parallel the cells for a day or so- for the BMS & preventing the need for a bottom balance?
* Do you think it might've performed slightly better (275 -280AH) if you had bottom balanced?
Great test, great review & THANK YOU 1,000 times!!! I genuinely appreciate your efforts. Noted: another gentleman purchased 16 cells for a garage solar power project and he only was able to get @ 250AH or so. Perhaps they are slightly less powerful and they DO have limitations (none that will disturb me using them..) But, they still have a TON of stored power & the chemistry lasts for so many cycles!!!
Dave
Its the role of the BMS to handle balancing for you.
Having the cells connected to a bms for a day should give you the same result as connecting them parallel - they should get balanced.
And a BMS is safer since it wil reduce/regulate the balancing current.
* Thanks!! :)
* The read/black cables coming off the battery were 4 AWG. The black cable from the shunt to the inverter was 1/0 AWG as I already had a piece with ring terminals crimped on.
* One thing I find interesting about the prismatic LiFePO4 batteries I've looked at is the capacity is usually given at a 1C discharge. I find that hard to believe, but I haven't tried a 1C test to see what happens. With this in mind, I think a 0.28C test is close enough to 0.2C commonly used by NMC chemistries. Lower amps may have resulted in another Ah or two, not sure.
* The spec sheet for these batteries gave 2.5V as the low cutoff. The BMS was set for 2.2V. I can't change it for this particular BMS and wanted to leave it go to see what would happen (if the BMS would shut off). The voltage drop at that point in the discharge curve is so steep that the extra between 2.228V and 2.50V didn't make much of a difference.
* Yes! I do think paralleling beforehand would have helped. I will be testing this later this week to see if there is any difference. I will report back my findings. I don't think the iCharger balanced long enough even though I had it set to "slow balance".
@@LithiumSolar I hope that you understand that I'm NOT questioning you in a 'snarky' way, I'm really trying to learn more (and, I'm more of a NOOB!) while being 'clear' instead of loose. Thanks (again!!!) for buying & testing these- I so appreciate all of your efforts! I was planning on using (2) Bluetooth programmable BMS' recommended by Will Prowse & paralleling them on arrival, discharging to a lower state of charge, balancing- charge & do a .2C rate test. .28C is so darn close- it thought it was higher (my bad!) Either way, 271AH is purdy darn close & still an exceptional value. I DO wish you had received 'matched' cells by lot as well as charge profile & resistance but at that price- it may be too much to ask! Hahaha
@@hubertnnn I think that Daly BMS' only charge at the very top of the charge cycle, and, often needs several charge cycles to balance the cells. When installed, the cell voltage variance was too large for it to even work. The resistors are pretty small on most BMS' that I've ever seen. With such a flat discharge curve, the amount of voltage in each cell can be pretty large -especially in 280AH prismatic cells!
@@DCGULL01 being snarky didn't even cross my mind... Out of all the comments, yours was the one I pinned lol. I am not an expert and am here to learn too. One reason I make these videos is I love reading through the comments, ideas, hearing what others are doing, etc. I do agree, 271Ah is still fantastic - I guess I just expected to see the full 280Ah after what I've been reading from others. I'll be ordering my next batch from Basen (seems to be who most are recommending) and getting 16 at once. Hopefully those will be matched. I love the Daly BMS for small builds and testing, but I'll be using a Batrium on my final production setup :)
You got 97% of the rated capacity, and your breaker and negative cable were generating some heat. The 300 mV drop from the terminals to the shunt is also about 97% of the voltage, so the cells seem to be pretty close to 280Ah. And for that price, seems like you did well!
The losses in cables, breaker etc do not affect Ah-measurement. The shunt measures the current going through the circuit and it does not matter where the energy is dissipated, whether in the actual load or elsewhere.
@@mcg6762 Errm. No. I don't believe that is accurate. Any losses between the terminal and the shunt (which is where my comment clearly identified the 300mV loss) is dissipated as heat before it any measurment by the shunt. That 300mV X (the amps) equals power lost at any moment, and power lost over a period of time is lost energy. See the First Law of Thermodynamics--the Law of Conservation of Energy for more info.
@@daveduncan2748 Ah is different from Wh. The shunt measures current. All current must go through the shunt, regardless of where the voltage is dropped.
@@mcg6762 i think he is sating you would need a shunt at each separate hot device to catch what its individual loss is.
@@The2000redrocket If you have more than one shunt in the same series circuit they would all measure the same current. Basic circuit theory. The current is the same everywhere for a straight series circuit.
At that price i would say close enough for the AH.
Agree!
Yup!
heck yeah
Many users are buying from this resller called XUBA and specifcally asking for AMY as there rep. I bought 32 all same qr style code and tested to full 280 ah. Running a 16s2p setup on a 48V mpp solar LV5048
I bought from the same source (Amy at Xuba) and got pristine cells as well.
Amy is no longer with Xuba, she's now with Shenzhen Luyuan.
@@alharrison3255 You are correct, elsewhere in the comments here, I have linked to the new company she started with her husband. Good service, good prices, and she doesn't exaggerate (aka lie) to sell you a product. At the time I purchased my cells, she worked at Xuba, now she has her own company at szluyuan.en.alibaba.com/
@@john_in_phoenix I didn't read every post, so I missed yours.
@@alharrison3255 not a problem. I make no money from recommending her, I am just a satisfied customer.
I've watched a few of these for the 280 ah and most get the 280 or close with all the wiring and such 271 seems close enough for me. You do great work thanks.
The bms cuts out at 2.28v so he didnt pull the max ah from the batteries
Wow! a most excellent video. Great production. Lighting, audio quality, and your narration. Just easy to watch, and appreciate your thoroughness. Going to watch more of your channel. Thank you!
Your video shows the value of a testing setup and spend time on balancing and discharge testing new batteries. Thank you
I've been debating selling my 16s NMC pack and dropping $10k or so on a massive bank of these. I don't like that they don't even have the rated capacity out of the box though. Thanks for digging into them!
Find the good seller, based on reviews mostly... 16 batts should be around 1.5k!
@@domatic 15k vs 1.5k
I do believe the chap said the bms cuts out at 2.28V not 2.2v so how can you say the batteries are not at the rated capacity?
As an Australian, planning out batteries is a challenge. Throwing money at the problem, yeah I can get battle-born's. But that's AU $1300, not including shipping. Local suppliers appear to charge similar prices for what the US market would call the B-grade to Battle-born.
Not sure about your datasheet, but Off Grid Garage found that his 'manual' said to let the cells sit for an hour after charging before starting the test or something like that.
yes I heard 30 mins, so 1 hour is probably more correct
Great Job ! I’ve gotten 280Ah 3.2v Lithium Phosphate from AliExpress about 108.00 each and I asked if they were grade A or B and the seller wrote back Grade A being made as they were written ! I have not tested
You commented on the heat build up and forgive my answer I did not spend a lot of time on research but is probably lost amps due to this.
Reducing the Amount of Power Lost as Heat in Wires
On the previous page we saw that transmitting serious amounts of power down an electrical wire at 230 Volts would result in incredible amounts of heat being lost in the wire. What can be done to help?
The power lost in an electrical wire is governed by the equation Power = Current squared x resistance. So to reduce the power loss, we just have to reduce either the current or the resistance. To reduce the resistance of a wire, we need to make it larger. There will be more metal to carry the current, so the resistance will be lower. Unfortunately, we would soon end up with an enormous wire, which would be hideously expensive.
The better solution is to reduce the current. This has the advantage that if we can reduce the current by ten times, we will reduce the power loss by a hundred times! (Remember, power loss in wires is equal to current squared times resistance.)
How do we reduce the current and still transmit the same power?
Simply increase the voltage. Remember, Power = Voltage x Current. If we increase the voltage by 10 times, we reduce the current by 10 times, and this reduces the power lost in the wire by 100 times.
So let's go back to our small town using 23MW of power. If we tried to transmit that power to the town at 230 volts down wires with a resistance of 1 Ohm, it would have needed 100,000 Amps of current, resulting in 10,000MW of power loss. However, what if we used a High Voltage power line running at 132,000 volts? (132kV) This would reduce the current required to just 174 Amps. Transmitting this down a wire with a resistance of 1 Ohm would result in just 0.03MW of power lost as heat. To provide 23MW to our town, we would have to send 23.03MW down the power line.
The longer a wire is, the higher its resistance will be. If a piece of wire has a resistance of 1 Ohm, then a piece of wire twice as long will have twice the resistance, i.e. 2 Ohms. This means that longer wires lose more power due to resistance, so the further you transmit power, the more you lose as heat.
Clearly, you would be mad to try and send electricity a long distance at low voltage. You would use a high enough voltage to reduce power losses to an acceptable level, and that's exactly what happens in real life.
But how do you change the voltage? As I said earlier, the two ways of generating electricity are direct current or DC, and alternating current or AC. The reason why we use AC in our homes is that it is easy to change the voltage, whereas with DC it would be very difficult.
btw. if you hook up all cells in parallel for a day while charging it as a 1s4p pack, you will have perfectly top balanced cells to start a test with.
I will be doing this and re-testing out of curiosity later this week :)
@@LithiumSolar It can take sitting at that level for quite a long time to balance them as you increase the number of cells. With 4 you might not notice as much, but when you have 8 or 16 cells in parallel they won't really be balanced. I believe it is due to resistance.
@@LithiumSolar The results would be interesting thank you.
Note that the straight forward method of connecting cells in parallel isn't the best. Reversed blocks of two is optimal, according to this author: www.solar-electric.com/lib/wind-sun/Iota_balanced_charging.pdf
hello, after one and half year, i would like to know how it's going on? how many cycles? and how many Ah left?
Tks.
Man, great video. Your whole presentation was straightforward and no fluff. Keep up that great work.
I'm on the more patriotic side of things generally, but what the heck is up with all these EVERYTHING FROM CHINA IS TERRIBLE comments? And why do they generally seem to be sock puppet/troll accounts? Anyway... like others have said, thanks for (potentially) taking the hit and trying these batteries out. I've also been looking into off-grid options, and this info is extremely helpful and interesting.
I wouldn't say everything from China is junk, but when you order from a non-branded store that may not care about developing a good reputation with buyers you may end up with junk that nobody else wanted mis-marketed. This happens with such frequency that it isn't surprising that they were under capacity or mis-matched. What was surprising was that they were as close as they were. China can, and does make high-end products. They just come with much higher price tags and are usually sold by "reputable vendors" By that phrase I don't mean something like Rolex, or Nike. I mean a vendor that cares about fostering a good reputation.
Think of it like this. The DMV doesn't really care about the reputation. You can spend well over an hour waiting there and it is considered normal.
Starbucks does care. If you spent an hour there it is because after they got your drink made for you in about 5 minutes, they provided an atmosphere that you wanted to stay at.
The same situation happens with e-commerce stores. Some spend a great deal of time fostering an atmosphere and trust. Others don't. Alibaba is like E-bay, with less buyer protections. Sometimes you get lucky. I've gotten lucky before. Sometimes, you don't get lucky.
Per the spec sheet from Eve, two are 2019 manufacture, and two are 2020 manufacturing date. Lower volume places frequently have stock sitting on the shelf a while, all of mine from a different vendor were manufactured in the same batch in the second half of 2020. Depending on the state of charge, sitting on the shelf for extended periods of time can lower capacity and lifespan. I suspect what you received was just two older cells, and everything passed all the manufacturing tests at the time, rather than grade b cells. I am sure they are not matched cells, which is different from grade a cells. It is actually quite difficult and time consuming to match cells, since the most commonly used measurement device for doing so clearly states it is not accurate above 100 amp hour cells.
That is a lot of eneregy storage and charge cycles for the money! What I don't like is the 6mm lug screws and the few threads that actually thread into the aluminum lugs. I built a battery using 240 ah cells purchased directly from Shenzen RJ Energy. One of the lugs stripped out even though I am very careful when tightening, but I was able to tap a larger screw into it and salvage the cell. I built a custom insulated boz with a silicon pad heater in it so it stays warm in cold weather. I have used this battery in my RV for 2 years now and it has worked perfectly with 400 w of charging PV's on the roof. I have never run the battery out when boondocking for weeks on end in the summer and up to one week even in late October in NE Washingon. The 280 ah cells you have are about half the cost of the 240 ah's I bought in 2018. They are a great value if you are capable of building it yourself. I think the fragile lugs make it best for stationary installs like a remore solar cabin , and less desirable for vibration uses like an RV. I check my lugs all the time and so far so good, but I think its just weak for high vibration uses.
Thanks for the review. I just ordered 4 280Ah cells from an eBay seller for about $170/cell, so not as good of a deal as yours... I’m just hoping they are matched, new cells, as they were advertised! This makes such a nice, compact, high capacity battery. Even at what I paid, it will be cheaper per usable amp hour than purchasing AGM batteries (considering 80% DOD for the LiFePO4 and 50% for the AGM). Thanks again for the review/capacity test!
I have just purchased four cells this week through Aliexpress. Delivery 30 to 50 days :)
270,271 what ever it takes. Beats battleborn all day long.
Exactly! Those extra 8 or 9 ah isn't worth the price.
It's true Battleborn is kinda overly priced. But it's a battery with a dedicated BMS - a finished product and these are just raw cells. And they give a warranty, but you get nothing like that with these cells, no one knows what to expect in long term usage.
@@cenchloraadums3143
A BMS module for a100ah battery bank cost $30.00. Four 100ah lifepo4 cells cost $180.00. Less than 1/4 the cost of battleborn. Even grade b batteries last more than 5 years. Spending $1000.00 on a 100ah battleborn battery is stupid, stupid, stupid.
@@drneedles7093 There are BMS modules even for 15 $. But if you go for sophisticated, yet reliable BMS, then you have to pay at least 50 $ and for reliable 100Ah cells need at least 300 $ even in China. So it won't be as cheap as you say, but let's say 500 - 600 $ including the battery case, costs of shipping and everything else.
Anyway, you're right that 1000$ for a 100Ah battery is insane. And that's how most of products are priced in a place where people are like "oh it's dirt cheap, just xxx hundred bucks" and pay what would be a small mortgage where these products are actually manufactured. Lol
@@cenchloraadums3143
Your math is off. I've had a set for 2 months. They're fine.
That alligator balance leads is a good idea I think I'm going to have to steal that
Off Grid Garage has been running heaps of tests with these 280AH LFP. I think he has ordered from Shenzhen Basen and they seem to have a small factory. Alibaba has tabs with company profile stuff. There may be other larger factories. Merit Sun has a YT video and they have a very advanced facililty. You have all these people dissing Chinese batteries but the tech says the Chinese are the leaders. You have to sort of figure out who the supplier is, whether they produce the cells or resell, stuff like that. To me this pricing is 'for real' and I love LFP so this is good. There was an article last week on pack prices for LFP at $100 a kwh. It all fits together. See if you can find a factory or a supplier and get comfortable with them. These cells are OK but I'd rather have fresher and from a matched batch. There's a long way to go with this stuff.
271 is quite close & good for first run. Your readings might possibly be off by 1 or 2 % anyway. Several cycles should increase the measurements.
also count the BMS and cable loss
Very comprehensive test , nice to follow with good explaining and commentary. Nice equipment also.
Very good review.
400mV difference between cells at the end of test seems too much.
Clearly not mached cells.
I'm sure if you pay an extra $100/cell, you could get matched cells. Most people prefer cheaper price and "good enough" or "close enough".
@@john_in_phoenix What is the real world issue with unmatched cells? Just curious since I don't know much
@@dansmith6990 Basically with unmatched cells, the lowest capacity cell is the max capacity of your pack. Some cells are also "runners", meaning that they change voltage rapidly just before full or empty, thus cutting a little off the top or bottom of the complete pack as well. Most packs of 280AH cells I have seen get from 250AH to 270AH due to these mismatches.
That’s a small package for a lot of battery. 280 ah. Wow
Nice video. Thanks
Part of the capacity loss would probably have been the wire used...When you first start the test, if the wire gets warm, its telling you that the gauge is not low enough and you have a bottleneck. When that occurs you are wasting energy in heat. Bigger wire (2 gauge) and retest. I also would never keep draining those cells past 2.5 volts, as there is little to no energy left after that point, and you are stressing the cell by doing this.
Pretty good for the cost.. still not as Advertised!
Truth and honesty is the most important thing when selling a product!
Thanks
✌️PT
Love that battery monitor app on your tablet... where can we get it ? Thanks !
It's something I put together myself using a Batrium BMS shunt and Grafana graphing software.
@@LithiumSolar Would be cool if you could github that for us.
Thanks for the review. Such cells seem good and powerful, I even used them for welding directly. They have the or near the stated capacity. What we should research is their life-cycles. This is the only way to see if they are viable or not. You can find cells apparently with excellent specs that do even beyond the specs in initial tests but they quickly drop capacity after only a few full discharges. I've seen this in some cheap and apparently very good Li-Ion 26650s. I don't have the means to do an efficient cycle test on high capacity LiFePO4s. I doubt they get anywhere near the stated cycles.
I should add that when I got them, I hooked 18 of them in parallel and used my iCharger x8 to do a 1s charge to 3.65vdc. it took about 3-4 days, lol. it was awesome though.
18? are you super crazy? you should have used 5 chargers to charge that many cells
I’m going to build this batt, you’re the 2nd vid I’ve seen about this & for the price, you can’t go wrong 👍👍
hey, two years later, are they good ? do you recommend that i buy ?
@@tariqalmutairi1403 actually, rack batteries are so cheap now I’d buy them so I have a warranty & a professional looking installation. I saw 48v 100ah rack batteries for $1150 recently.
Dude, fantastic test ! Yes in the industry we're using automatic expensive equipment to cycle cells for test, but the test seriously boils down to what you have done - GREAT ! IF you are planing on using prismatic cells long term I would only suggest to provide a box that applies pressure to prevent cell swelling, but I think this is redundant since you seem to know what you are doing !
Question for you. I have heard that if it was stored for a while then it needs to be cycled a couple times to pull full capacity. Does this seem to be true?
These cells do seem to settle down to more consistent results after a couple of higher rate charge and discharge cycles, but as someone already explained, they also need to be cycled every 6 months when stored. The QR codes indicate that two of the cells were manufactured before December of 2019, and likely sat on a shelf without being cycled.
How are the cells doing after 3 years? Thanks for the video.
Good. They're still sitting on the shelf :) :)
@@LithiumSolar ohh, so you never used them(?)
@@extendedp1 Correct. I test a LOT of batteries on this channel, more than I have an actual use for.
I suspect you are losing at least 3-5% of the battery power from Cables, BMS and Circuit breaker. I always try to double the ampacity of any device that passes the full current to the output. So in your case you would need bigger cables that are designed to handle at least 160 amps, probably 2 ga to 0/0 ga for that run length at that voltage. The BMS should be 150-200 amps rated. And at least a 150 amp fast trip circuit breaker. All these together should reduce your losses to heat generation in the components by up to 50 watts.
If you did a direct capacity test on the battery you would likely see just over rated capacity, with no hardware in between.
Keep up the good work, and Merry Christmas :)
Thanks so much for classroom technical data on these batteries. I currently have 2 200ah AGM batteries. They charge up great and fast (no complaints) I just have 70 (max) of only one battery for usage. I live full time in my van and after 1 year full time I’m ready 4 a change. I just can’t afford 2 Battleborn type lithium. Thanks 4 great post and channel. Look forward to more videos on this subject.
What about performance after 3 years?
Maybe in the trash
I love the way how you concetrate the right infos in your video and focus. Well done ! I wish every youtuber would do that. I am waiting for my cells coming from China in a few weeks and i gonna build myself a 24 200ah solar battery pack for my camping van. I am looking for how to test my cells the right way so i know what i got for my money.
on the alibaba link you posted, is the cost for one cell $332? or is that for a pack of 4 cells?
The price is for 4 cells
@@LithiumSolar thank you✊
Great video. Thanks for sharing
Thanks!
This is like those "bargain" bags of apples where there is always exactly one in five that are bruised or mushy. They start with good and bad separate, then carefully mix a "tolerable" level of bad with the good. And hope the buyer believes it's randome.
look who dropped by ..
@@terryterry1655 Who? I'm confused...
@@LithiumSolar dude! The OP of this comment. Never heard of him ?
How can you see batrium info on a tablet i can figure it out how to do it?
Hi hi, for your first link to alibaba, it says they ship out within 7 days. Was your delivery time pretty good?
It took about 7 weeks for it to arrive after day of payment from what I recall. I used sea freight (cheapest method).
With a software BMS, can check all data easy. Good video and beautiful inverter
I was wondering what is the reason for placing your circuit breaker on the negative side of the battery rather than on the positive side ?
Because I had a red cable with 2 lugs crimped on already and didn't want to cut it in half for the breaker. This was a test setup. It's best to use a double-pole breaker in DC battery installations.
Great video. Thanks for the specific information. Keep up the good work.
Good test. I wouldn’t be cut up about about 96.4% of the rated capacity since by your own admission there were heat losses (resistances) in your circuit that happen before the current shunt. Well done though and thanks for a good review.
Didn't find anyone mention the numbers, but if you add in the line losses, you'll be closer than than 271ah mark. Still not crossing the 280ah barrier though. In future, if possible, for a testing rig, try shorter cables to reduce line losses?
Nice test and clean setup. Clearly resistance losses don't affect amp hour testing, they become part of the load and only reduce watt hours measured. The accuracy of the amp-hour measurement (including shunt, shunt voltage measurement and time accumulation accuracy) would need to be verified to validate the overall amp hour accuracy. These cells could be within spec and the result error (-2.9%) within instrumental accuracy. Batrium mentions 1% typical accuracy for the shunt component alone and "typical" isn't a worst case guaranteed spec, plus this must be added to the inaccuracy of the measurement subsystem. Not a bad result.
Sometimes I do this test in reverse to see how much I can put back in as you can't get out what you can't put in plus you get to see how efficient they charge, Cheers
I do the same as we’ll also be accounting for any losses to heat the wiring with the fill method. For true output, the draw method is more correct for identifying the energy available, but the circuit modifies the cell capacity with losses.
Great test with lots of important details...this kind of videos are actually rare.
I think these cells have been used for at least several hundred cycles. If they're within volumetric and gravimetric energy densities of LiFePO4 chemistry, that should be the reason for lower capacity.
Even discharging at 280A (1C) they should give over 90% of rated capacity.
QR codes with no battery capacity are suspicious. These cells last thousands of cycles so they're refurbished (blue protective film re-wrapped, QR code + top black plastic film reattached - no big deal) and resold as brandnew or grade B cells depending on their condition.
Finally, wire losses would only matter if you measure the voltage at the load. If the volt terminals of wattmeter are connected to battery terminals it measures total energy, including that dissipates at wires. However, power loss at aluminum bus bars (if there's any) may still left uncounted.
Likely the two manufactured in 2019 sat on a shelf without being cycled every 6 months like the manufacturer recommends. I wouldn't suspect used cells, much more likely improper storage conditions. The cells will very quickly degrade if stored fully charged or fully discharged, and must be cycled every 6 months of storage. Recommend state of charge for storage is 20 to 50%.
JFYI - for common metric thread sizes (M2 - M24+) you don't have to mention thread pitch.. it's not as complicated as the imperial system.
Only in rare cases the thread pitch differs from the standard and it usually involves custom applications (say optical instrument optical path threads) or some designer wants to make sure that a certain grade bolt is being used (car seats for example need hardened bolts in my car and thus come with a non standard M10 thread pitch of 1.25 mm instead of 1.5 mm).
Interesting info, didn't know that, thanks! The metric bolts/screws sure are easier to remember and pick out in the hardware store... lol
The aluminum canning is connected to positive. Would you build a pack like your present with an additional isolation between the cells for RV DIY battery builds.
Thanks for your opinion
Bob
Yes, I would put a spacer between the cells in a permanent installation. I wouldn't rely on the plastic wrapping alone, especially in an installation where vibration is present.
@@LithiumSolar What material do you recommend? What thickness?
I purchased 16 pcs of 3.2V LiFePo4 cells on AE, Ogreen Lifepo4 cell Store, store number 5729174
The cells were rated minimum 180Ah. The best I could get from a 8s2p configuration after connecting the highest capacity cell with the lowest capacity cell in parallel was 240Ah which is 120Ah per cell. The cells internal resistance is a lot higher than specified.
Oh my god. U look just like my grandpa Smith.
40’s. When I was 5or6. I am now 83. I have less hair then u. He died of an enlarged heart. I am a 22 year survivor of 5 heart bypass. Just subscribed.
Thanks for the video. At first, I thought it was going to turn out bad when they didn't quite match in terms of build. But the results aren't too bad. Definitely didn't scare me away from ordering some.
Can you do an update on this brand of cells? The video is about 4 months old are they holding up? I am thinking of buying but endurance is my concern on Chinese batteries, thanks
Great video, question: can I lay the cell side way? Will it leak or effect performance? I am building a power box and laying side way give me more room to play with , thanks
Lithium cells are not like lead acids you can place them any way and nothing will happen to them.
It's generally accepted that the prismatic batteries can be placed in any orientation other than upside down. You should consult the manufacturer's specifications though for the specific cell you have.
I'm currently devouring as much info as I can in advance of building a solar system, and I have gleaned elsewhere that it is wise to discharge these batteries first, in order to do a "bottom balance" which sets the baseline, and then test them. If you need any information along those lines, then can I recommend Will Prowse and his excellent set of instructional videos, I think that he was weaned on battery acid with a digital dessert!
For real great info, thanks Ron Howard!
How long did it take to ship these cells and did you have to pay for shipping?
It took approximately 8 weeks from date of payment to date of delivery. And yes, had to pay for shipping.
Love your precise, detailed presentation style.
Heat in the bms and breaker are amps used. Your shunt should be before the bms for 100% accurate test.
Circuit breaker on negative? Never seen anyone do that before...unless you are just using it as a switch. Great presentation
The circuit breaker will break the circuit the same on negative as if it were on positive. It's just a test setup...
Well done. Do you think two 12v configurations could be wired in parallel to work with an existing 12v system? Looking to replace a set of 12v AGM batteries.
Yes, you could wire two 12V in parallel. You will need 2 BMS that way though. I would first wire the cells in groupings of two (parallel) then wire those in series such that you only need one BMS (4s2p). As for replacing the AGM batteries - you will need to check that the device supports LiFePO4 batteries to prevent over charging/discharging.
@@LithiumSolar Thank you. I did not know about the 4s2p BMS. Any thoughts on detecting low temps to prohibit charging?
@@patrickmchargue7122 newer models of the Daly BMS like he used have low temperature cut off, but you have to ask for it when ordering. Newer models can also be purchased with Bluetooth and USB ports for monitoring and changing parameters, but again, you must specify when ordering.
@@john_in_phoenix Thank you.
Great content, thanks for making these videos. I have the same X6 charger but can't find a cable for the cell monitoring (the white wires with the alligator clips). Can you provide a source to where you got yours? Thanks
The connector for the balance leads is a JST-XH (you can search this on Amazon). I soldered the alligator clips on for ease of use in videos.
seriously?
What is the cell balancing performance(or ability) of this bms? Wouldn't it be necessary to install an equalizer(Active balance)?
Thanks for test.
I have same cells from Alibaba(different seller) and I did test capacity with two different metering devices and my numbers came very close to 270 AH as well.
If you divide 270AH to 280Ah the percentage of capacity would be %96. They state that the cells are grade A and brand new but if you look at EVE specification booklet(or PDF) and look at Fig 3 "cycle performance", the 96% capacity means that the cells have around 750 cycles on them.
secondly I contacted EVE company to read the cell specification from barcode(incuding production date) but they denied and said if you don't buy from them directly, they would not read the code. When I asked the seller on Alibaba they did not provide me an exact date and just said it is 2020 production. That may explain why they changed the barcode type on some of your cells from production date/line of assembly/serial info to just EVE 280AH maybe to stay out of trouble.
Now with my test result confirmed, I am pretty sure the cells are not grade A and used because of 96% capacity and the EVE company is selling on Alibaba directly but prices are almost twice as these.
With prices around 120/cell ,I would say it may still work easily another 2000 cycles to get to 80% capacity so it may still worth trying but I would not trust these building a huge power bank like off-grid etc.
Cell QR codes changed in December of 2019. He received two cells manufactured before December of 2019, and two manufactured in 2020. The manufacturer clearly states that the cells should be cycled every 6 months in storage. They should also be stored between 20 and 50% state of charge. Likely these just sat on the shelf somewhere for a while.
@@john_in_phoenix The problem is that you can not verify if the info on those QR codes unless you buy them directly from EVE for much higher price. So something is off here. Having all 4 cells down to 96% of capacity in my opinion is more consistent to have specific number of cycles on them. If the loss of capacity was due to sitting on shelf and 2 of them are 2019 and 2 are 2020 we may see different numbers of capacity loss.
@@VEMNEM1 At least some of the information is easy to verify by just looking at the spec sheet. The ones with the old style QR code were manufactured before 12/22/2019. The ones with the new style QR codes were manufactured AFTER that date, and indeed will tell you the exact date of manufacture (on the sticker). You can get the "decoder" spec sheet for some (but not all) of the QR fields here: diysolarforum.com/resources/eve-lf280n.139/
Prismatic probe online. Phase crystals charged. Calibrate void lens. Prismatic beams aligning
Please give details for the display you used to monitor the voltage
Bottom Balance along with Top Balance and you will get much more energy. The one cell shut down the BMS while other cells had energy remaining.
Good job though ! Thanks
very well explained. The measuring instruments you are using; can you please share the brand name ?
It's the shunt from a Batrium BMS www.batrium.com/ It's not designed to be used this way though. I wrote my own custom code to do this. The tablet is a Samsung Galaxy Tab A running Grafana.
thank you very much for your prompt response. Stay blessed
@@LithiumSolar Exactly what kind of code did you have to write?
@@RandomTechJunkie It's NodeJS. I started with this github.com/Batrium/WatchMonUdpListener and pretty much rewrote it to fit my needs (such as a MySQL database, multiple Batriums on the same network, etc).
I think it would have been better to parallel top balance, then disconnect the charge and and let them soak as a group for 24 hrs. There’s a very good chance that even with the best BMS eventually the mismatch of most of these “280” ah cells will be too much for the BMS’s tiny balance resistors. I highly recommend the newer Heltec capacitive type “active equalizer” (balancer) to be used WITH your chosen BMS. Also, avoid running groups (series) of 12 to get higher voltage. If you need 24 volts build a 24 volt battery and BMS/equalizer.
Great video. getting ready to buy these cells. really great value now on Alibaba. $459 for 4 of these cells
Hi, thanks for great info. I have a comment about the M6 screws, though,
In order to use the full depth of the inside thread and compensate for different thickness of bus bars, I recommend to take longer M6 screw, cut the head off and then fully screw it in as a post. Then use M6 washer/nut to tighten the bar to specification. Just a thought. Cheers.
Most people use 25mm m6 studs (they have an allen head) rather than cutting off screws. McMaster Carr has 10 packs for $3.52 (stainless steel).
Threaded studs and flanged nuts seem to be the best option for these cells.
Apparently it's really easy to damage the threading as it's an aluminium terminal
@@w3bb0y Some vendors just started offering studs welded in rather than tapped holes. Probably costs extra, but that is an option that I would pay for, the aluminum is too easy to strip when trying to get a nice tight connection.
So how long did the space heater actually run off the battery pack you made?
Supplier is everything. Keep us posted
The 2019 spec sheet for the cells says (in testing section), that the capacity is only valid for one month after leaving the factory and before 5 cycles (charge/discharge cycles). This leaves an obvious out for the manufacturer to say it meets spec, you just tested wrong. I think everyone would be happier if they just rated it realistically (like Leishen rates an almost identical cell as 272AH). I have 16 of the Eve cells, and I am running capacity tests now.
Isnt it the same as if you bought a car that says 33mpg but when you drive it in real condition you get 25mpg?
Another amazing video , detailed and clear . Thanks so much for your easy to follow vids . Love em ! Take care
Great video. Out of curiosity how long does the heater last before battery is too low.
Thankyou
excellent demonstration
Very professionally, thourghly done.
does having them connected in parallel automatically balance them? (assuming the voltage is near identical when you connect them so it doesn't blowup)
nvm I see several studies that say they should be left in parallel a few days before building a battery
Thanks for sharing 👍
Can i ask some question sir, I have 3.2v 100ah connected in 4s, what should be the BMS rating (amps) I would use?
0:12... is that each or for all 4 ? After your initial power test I would have recharged the batteries and done the test for a 2nd time to verify the results since you dis not start with depleted batteries with the first test.
The price was per cell, so multiply by 4 :) I will be re-testing later this week after manually balancing by connecting in parallel.
Did you say $116 shipped? Is that for 4 cells? The link you provided is priced over $300.
Yes, $116 per cell. The price on the Alibaba page is for 4 cells. Add shipping and divide by 4 to get per-cell price :)
LithiumSolar Got it and thanks for making this great video!
Can you run a charging test to see how well it balances without the balancer? Likely they should charge pretty evenly, mostly the BMS should not be needed?
Thanks for this! You mention that your circuit breaker was getting warm, but I notice that the shunt is not measuring any power consumption by the breaker itself, as it is wired after the breaker. You might want to change this, and install the shunt as the first item from the battery, that way you'll be recording any power that the breaker consumes. Perhaps that is where your missing amp-hours escaped to... Cheers.
Exactly !
But didnt the same current that went through the breaker goes through the shunt?
Question please, why do you take the battery all the way until the BMS shuts off to get the current? I would think a 12v battery pack you will need the 12 v to power devices as many items wont work below about 11.5 to 12 volts so then I would think when the total battery pack is at the 12 v or 11.5 v then thats the real amount of current that is real? As you really don't want to take the battery in to DOD even these are LIFEPO4 and can handle doing a DOD point I would stop at the 11.5 or 11.75 volts?
The low cutoff point defined by the manufacturer is 2.5V per cell or 10.0V for the 4s battery. The whole point of this video was to test the capacity of the batteries, and you can't do that with out a full depth of discharge ;) I would agree, in typical use scenarios, don't do a 100% depth of discharge and it will last longer.
Great breakdown ... one thing has me ... Building a powerwall is straight forward, I'd like to see an Automatic Transfer Switch for Grid to Battery power, I have a 200amp service, but the only ATS I can find seem to be 100amp, should I take the feed-in from the grid and split it one to a sub-panel powered by the ATS, separating out the circuits I want to power from Batteries?
Cool video. Was wondering why you put the breaker on the negative side? I thought breaker/fuses go on the positive side.
Thanks. This is just a testing setup here. The breaker will work on either the positive or negative. In a DC application such as this, a double-pole should be used so both polarities pass through.
so now Amy has LF280N Has anyone received these new better 290Ah batteries?
Great info thank you
how did u do the wireless lcd screen i want a setup like that
any idea why you only for 271 ah ? do you think its based around the condition of the batteries or inaccuracies and loses through the equipment used or maybe a little all of the above?
you do a gr8 job explaining things, thanks. the 3.65v might be in the specs as the max voltage, but it is not recommended as a voltage to cycle to at every charge cycle. at this voltage you wil severely reduce your overall lifespan of the battery. 3.5v is a better max voltage to use.
I would say for the price you paid, 97% is pretty darn good.
Great test. Would be great to have links to all your instruments.
How is it dealing with alibaba anyways ?
I didn’t know being in the USA that you could deal with them
Of course. You can order and have it shipped pretty much anywhere. If the supplier doesn't ship to your country, you can use a 3rd party freight forwarder. I've used both methods.