I am enjoying your enjoyment of what you have been achieving these recent years :) Great thought processes, application and scrutiny. I have no doubt that very many people will benefit hugely from your videos. I conclude that they are as in depth, detailed and concise, without becoming boring, as most could wish for in an educational/skill sharing video: I therefore offer, that you have got your spot and quality within it, just about as dead on as most could achieve. Well done. And thanks indeed for the inspiration and confidence to tackle some of my own very long overdue explorations that you have sent my way. Good on you dude.
I'm using this Solar charger with my DIY 3S 18650 pack. I used your values as you describe but for 3s voltage and not 4S like you are doing. I don't get full sun on my panel until mid day. But my pack never gets above 11.89 volts? I have drained it down to under 11 but it charges back up to the upper 11 range. It says on my software monitor that it's at 12.1 volts. But if I hook up my voltage monitor, it's always around 11.8 volts. I have upped the float and recon values but I'm still not going higher. Have you seen much difference between what the charger is showing and what the pack actually is. Any suggestions on other parameters I can change to get the voltage higher?
I keep nine at 4.0 volt. 28 volts total. My experience is that the cells will diverge quite a lot during charging and discharging so my daily balancing is a must. Also hoping the cells will last longer just charging them to 4.0 volts.
I think it’s a good shout. My smaller 7s8p pack charges to 4.05v/cell and the capacity after a full year was close to its original. After only a couple of days though my packs are staying very closely matched, but I’m not yet draining them much!
I have a 7s system too with a mppsolar 2424mse I only charge to 4.1v per pack and no lower than 3.2v this will drastically increase the life of your cells I have 2100 cells in total with another 700 waiting for 4x5 cell holders. After watching your vids im looking at one of these charge controllers as ive got too many panels for my 2424 to handle im also really interested in the BMS too.
Hi Adam.. Watching your videos inspired me to build my own 3s20p lithium power pack. One thing I have issue with, is how the wiring goes from battery with BMS to the MPPT charger and load. If you don't mind, can't you share the wiring diagram of what you have for the above setup, assuming with a load attached.. Thanks...
Pity you can't get the AN series to work with your WiFi to RS485 dongle.Might be worth knowing that the AN has a setting for LiIon and LiFePO4 charging on a separate page from Lead Acid batteries with default settings for 3S and 6S batteries. The main advantage for use with LiIon seems to be that that the software for the temperature sensor on the Lithium cycle allows you to set a temperature at or below which you will not charge or discharge the batteries. For winter, this is an advantage in a shed.
Adam, can you please tell us some more info on FloatCharging. This Float Charge debate is pretty confusing to me. How bad is it using FloatCharging on Li-Ion afterall? I noticed the voltages on battery differ from voltages mesaured on EPever solar charger. 16.05V on charger vs. 15.65V on battery. The EPever software readings are showing the values mesaured on charger correctly. But I have also a REC active-bms connected to my 4s9p battery pack and it's software is showing the actual readings from battery. There I spoted the differences. The battery never reaches the values set in EPever solar charger. The charger actually always ends in float charging the battery all the day with small current. 0,30A or so. The battery according to charger reaches 16.05V but it is really 15.6V. After long float charging the cells slowly reach near 4V each. The Float current is simply too small. I'm thinkig about setting the battery capacity higher to increase the charging currents but I'm not sure about this. But I doubt I wouldn't get my battery charged to 4V/cell without float charging. So I'm trying to find out, how bad is this Float charging for Li-Ion packs. I'm following your channel for almost two years and it is great inspiration. Packed with relevant information. Top work.
Here's and idea that might be useful to help the packs from warping or at least hold the Batteries if said pack does warp; and that is to use Zip Ties to close the pack. Long Zip Ties are cheap yet have considerable holding power so at least the Batteries won't fall out. Not sure if you have the room but a few small holes near where the Pack locks onto the Bracket should suffice... With Zip Ties you will be able to close the Open C design and should provide a bit of stability too... Cheers...
That’s quite a good idea. I’ll look to see how I could implement that. The new brackets are holding well for the moment - and temperatures are dropping, but it’s a good idea to have a backup plan.
By setting your float and boost recon so low it means there's a window between 4.16 and 3.71v where your solar panels are doing nothing and you are throwing away energy. In reality if you can keep your cells >4V all day that would be best so I would set the recon at 4.00 and the float to something like 4.05
This is an excellent point and has got me thinking. For me I don’t really use the power in the pack during the day - I’m out at work for most of the week. However that isn’t to say I might want to use the power, or I shouldn’t be wasting it. I need to have a think.
Adam Welch Yes, you want to keep the cells topped up while producing power with PV; not drawing the cells down, then reconnecting to charge. In this way, you'll ideally go into the evening with a full bank.
That's what a float charge is ... if your float is 4.05V and your cells are 4.05 then no current from solar will go into the cells... You need a voltage delta to have a current. The problem with his setup is he will cycle his batteries (partially) during the day when he should be capturing solar. Once the boost period is done no power from solar will be used until the batteries drain to 3.71V. In fact that article recommends 4.05V specifically ...Point is if floating your battery to a 90% charge "breaks it" then your battery is worthless. If the only "safe" state is "mostly discharged" that's not very useful. So ya you shouldn't float at 4.20V but floating at 3.7V is kinda pointless too. edit: boosting to 4.2 and floating at 4.05 also means you will cycle a bit before solar kicks back in which ensures you don't keep the cells at 4.2V all the time but also means that should solar go down you still have a mostly full li-ion cell.
Yup, but you also don't want to keep them fully charged all the time. Boosting to ~4.15V and floating ~4V (and recon at 3.7-4V range) would be best for most random li-ion cells/packs.
You could but that's what a float voltage is... If you take an 18650 that is resting at [say] 3.95V and throw a 3.95V power supply at it 0mA will flow into the battery. When your MPPT is in float mode it's bucking the solar power to the float voltage. So as long as that isn't too low or too close to 100% you should be fine. a float around 4.05V should be fine for any competent li-ion cell.In Adam's (current) setup he's burning energy until the cells hit 3.71V at which point any further draining will charge them to 3.71V. Whereas if he sets it to 4.05V it means he'll burn off the boost charge and then start using solar power again once he uses 10-15% of the capacity (per cell). Then at 4.05V solar will be used (if sufficient) keeping the li-ion mostly charged should the PV go down then turn to the cells. That kinda pointless since there's no need to keep the cells that low and you're throwing away a lot of solar power in the meantime (depending on the size of the battery array). He should have the boost to 4.15V +/- a couple 10mV and the float ~4.05V. That way he's never fully cycling the cells but also not depleting them needlessly during solar hours. edit to add: "technically" throwing 3.95V at a cell with a 3.95V charge will put current into the cell due to self-discharge but that rate is so slow for a healthy cell that effectively you're talking micro amps at that point.
Adam, not using CC in your setup is safe because the maximum current the solar panels can generate is below the maximum current eack pack can be safely charged at. However, it's important to note that if the panels produce more current than the batteries can be safely charged at, they will likely overheat and may cause a fire.
hrm I guess you dont have the float at the 4.1v mark because keeping Li-ion on the charger for a long time can lead to degradation, the problem is is that worse than discharging them deeper since you will be running the loads on battery power as soon as the boost charge was finished? basically it will charge to 4.1v per cell on a normal day with solar running the loads at the same time (power coming from the cells if the sun goes behind a cloud) then when the boost duration is done after 2 hours it will stop using solar and only run on the batteries even if the sun is still out, until it drains to the float voltage at 3.8v per cell. doesnt seem that efficient as far as getting every drop of sun it can. im sure it will probably never get a full 2 hours of boost before the sun goes away but still what if it does? or if you want to run a big load when the battery is full? the power could come from the solar as well as the batteries but instead once it is off boost charge all power will come from the batteries. im sure as long as you are cycling every day it will not degrade the cells by keeping them charged all day.
Hi Adam 10:25 you talk about setting the over volt disconnect to 29.75volt. I have tried to do the same, but the software in the controller only allows to be set to 29.7 volts ? (5mv in difference) Did you really set it to 29.75volts ? the same goes for "Charging limits voltage" as 5mv steps is not possible to set.
you might consider changing the 15A breaker between the solar charge controller and the solar panels to just an ordinary light switch if you need to repurpose the 15A breaker.
Excellent! you've done a great job on this. i do hope that it all works out and from what i can tell, it should. someone below suggested printing the mounts in PETG, both PETG and ABS have a higher melting point so they both may stand up to the heat a bit better. I just saw now that someone also suggested one or two 12v computer fans blowing across the battery mounts? good luck & keep up the great work! Russ from Coral Springs, Florida, USA.
Great little project Adam and a very informative video. You could break out part of that for a video on epever controller settings. Not much info on setting them up for lithium out there 😁
Make that bit into a separate video? Well those setting might change so perhaps once I have them set I’ll do exactly that - cheers. How did you find me doing it on paper rather than in the software or on the MT50?
Hello Adam, maybe you can help me with my problem, and I have the Epever Tracer 3210AN on a 4S Li Ion battery system. In battery mode "User" you can set everything from 9-17V and I have a list of values for such a system, unfortunately it does not charge over 15V although I have set Max 16V, basically it is not bad for the battery but there is not enough energy in it. Do you have an idea or the loader can't do it because then this user mode would be pretty pointless. mfg Marco
I’ve not taken anything that high but if your boost and equalise voltages are above 15v then I’d think about your solar - either there isn’t enough to get the size of your battery bank up to that level, or it’s not producing the voltage. It’ll need battery voltage +1volt at least. The boost and equalisation charges only last for a limited period of time - if you can’t charge your bank up to that target voltage in that period the charge controller will fall back to the float voltage. Hope that’s helpful.
Hello Adam, hope you are well. I could solve my problem with my Tracer AN and the misterious 15V limit. It was the BMS's fault that the charging process should be interrupted in an emergency because I had previously worked with a cheap china pwm loader and I simply needed security. Now the detail of the Tracer AN measures the resistance of a battery and then adjusts itself, but if there is a BMS in between, the resistance of the battery for the tracer is practically infinitely high and he does not know what he has in front of him, then switches the system at 15V depending on the system download regardless of what you have set. today i rebuilt it for the sake of trial and lo and behold, it loads exactly as i want it. Lg Marco
@@AdamWelchUK www.ebay.de/itm/3S-4S-5S-100A-12V-BMS-Li-ion-LMO-Lithium-Battery-Protection-Circuit-Board/173619538133?_trkparms=ispr%3D1&hash=item286c87e8d5:m:m57AFWhfXaFVmdHBbunhM6w&enc=AQAEAAACUBPxNw%2BVj6nta7CKEs3N0qVJ1RJ2kHJ8g3nnHNvvCYePmnnBax%2B3rZ5xNCSumTRm292NP3yUD4sQl811Yce%2FeYPvbX28g9rQeKhAjqkLwbLBnNDUBdUF6bx38zvhcKd0oEIiVpBJ7nDo%2Fji%2FmiA%2BRE6Xb7OUQKSjPD4SUEIa6mSKhshdZdC8tV6OrLaQ9U3SFCCUzzw5e8dNlZpox2lLr7O2LQgKOiEp4BFPBOBhZ69hqrb3OF0hlXSPRdmhRAL6nspjnIMSmTSd4BpS9CnmOJaC0btWrZv4%2FC4tNyFLqriO3yWR2%2BZFq9UkkxBIX3neBrxafSrkLBW6UMR3GIyRcGUkRNj0lJ5ND2xq7EVa1QxhGLWNZXHpGeKnbkZiiI%2BS%2FlIfv0%2FX21R3m1UQVvN7SOJCr2c%2FmyGxClqWTr8fqAFGFVaSlPoe3PIYh3SnpjkCvig7COZfhSViXJV4UfHso%2Fy8wqqlJDU731hAlR02vuYpa70qS2MCF9XIeN%2FTklFdfxgWlLLX6oYvNUppUUwnx9LCw0i7JgGNY%2Bm4IgW9JFXWL9tFdfqlsHFGoeJibJZM8j0B1JtCCtn%2FxuLBvMY4QIVasUKwdCBDIHDAHAg5UWQ90cI4dUz7fOixnYSOOw3rSS3YTOWSmu9RsncsWCsmbpgpmhJlCTkMCUjl6stQu0K7%2FuAvG8AEjbfh%2Br%2BGer8e393YYbvqYu%2BGS4htrpPmU0CURNynB4iqzNedJlQ%2BJug%2FDpAlsDIz2V70F2MTTHK%2BJgKJfKyWPnRQrEGKIOUYVfM%3D&checksum=173619538133a48dfdad71454fe79342f09465f9712e this boy was to blame, basically everyone who works on this principle
Sadly the shed isn't insulated and as mentioned by Mai the ambient temperature is high. It's rained already this evening and is notably cooler - I might be safe again until next year now anyway!
hi adam each pack is 3.7v connected to series for increase voltage right. how do you balance each cell in 1 pack using a bms if the bms is for 4 cell. sorry is you have a video covering this is so please le me know the link
You’re right that connecting the packs in series increases the voltage. However I have built a 7 cell BMS for my 7s20p pack. Each module is isolated from each other using the ADUM1250ARZ i2c isolation chip. It allows communication between the modules without a common ground (and prevents a short circuit). I hope that helps.
Adam boa tarde sou Ricardo do Brasil. Estou carregando um banco de lítio 3 s com o trace igual ao seu. Mas ele depois de um tempo baixa a tenção dos painéis e desliga o mppt, e com isso fico perdendo produção pode me indicar uma confirmação obrigado.
Hi Adam, wrt CC charging the PV panel peak power should be such that maximum current to the battery is below the allowed charge current. Normally 0.5C for li-ion batteries. In the CV voltage phase the current must be reduced to maintain the maximum battery voltage. (in that case the PV panel is not used optimally and no MPPT is done). I am very curious when you start measuring the charge behavior of the EPEver. I tried the same thing and float charging is not what you want and this stage is forced you can only specify the voltage but you cannot avoid it. Cheers
I have similar questions. CC phase (bulk) and CV phase (bust) are OK for me. But CC produces too much current, CV (bust) ends too early. CV mode ends after 180min, but there is still 3 Amps going into battery. So Float phase has to finish the charging. In my opinion the CC (bulk) phase produces too much current for my battery and the voltage rises too fast. Then CV (bust) phase doesn't have enough time to finish charging. So, is there a way, to limit the current in CC (bulk) phase, or is it only option to connect larger battery?
I think your analysis is completely correct. However when you limit the current in CC (bulk) phase what is the point in buying an MPPT charge controller. The only thing imho you can do is to choose a PV panel that delivers the maximum allowed current during CC charging.
Today I tryed to put smaller value for battery capacity. 10 Ah instead of 20 Ah. I was hoping that EPEver charger would put less Amps in the battery. 0,5C for instance. No luck. Bulk phase (CC) probbably puts all the energy it gets into battery. At least my model Tracer 1215 BN. My test battery is too small (20AH) and the current goes up to 8 Amps. The cells should handle this current. But the voltage is raising too fast in bulk phase, and the battery can't be properly charged throug Bust (CV) phase. I wonder if other models are any different. This data is hard to find.
Hey Adam, great vids. Had probes w commas with my AN through the eLog to my laptop. Don't know if it's the real fix, but I could only get comes if the load function is on. I don't use the load for now so had it default off, no comms, but on fiddling with it, powering all off n on blah blah, noticed I had comms when the load was on (no load attached) but switching off load then comms failed. Or maybe you found a solution since the vid was posted. Good luck with it all anyway ..
PLA can only handle 50c. PETG about 80c. Print PETG with 30mm/s and 240-245c nozzle temp. I print myself brackets for 2 solar panels in PETG just now. But I had to buy a new PEI magnetic Surface for 30€.
I got a job lot of laptop batteries on eBay. Unfortunately the prices seem to be going up and up. The other option is to go to a local recycler or laptop repair centre and start a conversation. If you go down the eBay route, be sure to carefully look at the images to see exactly what you are buying, research the laptop battery model to gauge age, number of cells and ensure they have 18650s if that’s the route you are going.
hello Adam, very interesting video, I'm trying to build an off grid system with 18650 batteries, and I would have some questions for you: I understand that float mode is not good for lithium batteries but I have not understood how you can avoid the controller enters float mode if during the day I take energy from the batteries (in fact if I take energy from the batteries when the battery voltage reaches the float level the controller enters float mode), or am I wrong?
Yes you can do it with either. MPPT is the way to go if you have limited space for solar panels, but otherwise PWM is fine, and use the money saved on your controller to buy a larger panel or array.
I HAVE 4 PANEL OF 100 WATTS PANEL AND I HAVE 2 100 AH BATTERY AND AN 2.2 KVA INVERTER BUT I STILL RUN INTO PROBLEM, IF IT IS MY PWM OR MY BATTERIES? BECAUSE MY SYSTEM GOES OFF, EVEN DURING THE DAY.
Adam I’m building my own power pack and start to charge with same solar mppt PAY ATTENTION : when using USER, after cutting with breaker or other power disconnection... this mppt loose settings !! Did you try this ? Best
Adam Welch ! Thanks it’s helpful to share ! I’ll try again and will let you know if I have same problem again... I’ll try to disconnect solar panel and battery.. to see if...
Adam, you seem to have set the peak and minimum cell voltage to the extremes the specs allow, rather than limits chosen to maximise cell life - if you intend to use this capacity in anger, is this prudent? Also - given the effort expended and the success achieved, do you plan to scale this up to the point you can move towards a solar house vs. a solar shed ?
You’re correct I have set the charge controller close to the limits. I’ll be monitoring my pack closely, and it hope to never get anywhere near the 3v per cell lower limit, but if I need to or something goes wrong, the setting is there. 4.1v per pack is a little higher than the 7s8p pack I have which charges to about 4.05 per cell. After a year, the captivity loss of that pack was very small. The settings aren’t set in stone - actually there is something I need to consider moving forward, and the upper limit is another one. I’ve no intention of running the house from this or any other pack at the moment though. Thanks very much for the input.
what do you plan to run from the pack? I've now been going on two years and still haven't worked that one out, but, now I have far more of a chance, in December I managed to get a mortgagor for a house weee so I plan to eventually (as fund permit) to set up a set of 12v LED lighting strings through out the house. and to run my new security camera and DVR from the other pack, as it all runs from 12v.
Sounds like you have a big (and satisfying) project to do - good luck with it. Having a 24 volt pack I can use will be handy with some of the kit in the shed - my 'bench power supply' should work a little more efficiently for example. However I think I need to find an inverter. If I find a nice quiet one I'd like to make sure the shed is fully off grid. My soldering iron (and my power tool charger - but that's another story) are both mains fed at the moment and I'd like that to change.
I've got a similar system ( imgur.com/a/rhrb6EM ) with my own DIY BMS. For charging I've got an SSR for interrupting the solar input. Once the cells reach 4.1V charging is terminated, and when they drop back down to 4.05V the solar is turned on again.
Hello from the Czech Republic, this video is incredibly helpful. I have been searching for this exact explanation for weeks - until now . Thank you.
I am enjoying your enjoyment of what you have been achieving these recent years :) Great thought processes, application and scrutiny. I have no doubt that very many people will benefit hugely from your videos. I conclude that they are as in depth, detailed and concise, without becoming boring, as most could wish for in an educational/skill sharing video: I therefore offer, that you have got your spot and quality within it, just about as dead on as most could achieve. Well done. And thanks indeed for the inspiration and confidence to tackle some of my own very long overdue explorations that you have sent my way. Good on you dude.
I'm using this Solar charger with my DIY 3S 18650 pack. I used your values as you describe but for 3s voltage and not 4S like you are doing. I don't get full sun on my panel until mid day. But my pack never gets above 11.89 volts? I have drained it down to under 11 but it charges back up to the upper 11 range. It says on my software monitor that it's at 12.1 volts. But if I hook up my voltage monitor, it's always around 11.8 volts. I have upped the float and recon values but I'm still not going higher. Have you seen much difference between what the charger is showing and what the pack actually is. Any suggestions on other parameters I can change to get the voltage higher?
Really helpful description of the various settings on the Tracer A. Thanks.
I keep nine at 4.0 volt. 28 volts total. My experience is that the cells will diverge quite a lot during charging and discharging so my daily balancing is a must.
Also hoping the cells will last longer just charging them to 4.0 volts.
I think it’s a good shout. My smaller 7s8p pack charges to 4.05v/cell and the capacity after a full year was close to its original.
After only a couple of days though my packs are staying very closely matched, but I’m not yet draining them much!
I have a 7s system too with a mppsolar 2424mse I only charge to 4.1v per pack and no lower than 3.2v this will drastically increase the life of your cells I have 2100 cells in total with another 700 waiting for 4x5 cell holders.
After watching your vids im looking at one of these charge controllers as ive got too many panels for my 2424 to handle im also really interested in the BMS too.
Hi Adam.. Watching your videos inspired me to build my own 3s20p lithium power pack. One thing I have issue with, is how the wiring goes from battery with BMS to the MPPT charger and load. If you don't mind, can't you share the wiring diagram of what you have for the above setup, assuming with a load attached.. Thanks...
Thank you so much. I have an EPever and will be building a 7s system very soon. These settings are super relevant to me. Thank you!!
Well keep an eye on future videos. The settings are not yet set in stone!
@@AdamWelchUK Hi Adam did you ever do an update video on your settings?
Pity you can't get the AN series to work with your WiFi to RS485 dongle.Might be worth knowing that the AN has a setting for LiIon and LiFePO4 charging on a separate page from Lead Acid batteries with default settings for 3S and 6S batteries. The main advantage for use with LiIon seems to be that that the software for the temperature sensor on the Lithium cycle allows you to set a temperature at or below which you will not charge or discharge the batteries. For winter, this is an advantage in a shed.
Adam, can you please tell us some more info on FloatCharging. This Float Charge debate is pretty confusing to me. How bad is it using FloatCharging on Li-Ion afterall? I noticed the voltages on battery differ from voltages mesaured on EPever solar charger. 16.05V on charger vs. 15.65V on battery. The EPever software readings are showing the values mesaured on charger correctly. But I have also a REC active-bms connected to my 4s9p battery pack and it's software is showing the actual readings from battery. There I spoted the differences. The battery never reaches the values set in EPever solar charger. The charger actually always ends in float charging the battery all the day with small current. 0,30A or so. The battery according to charger reaches 16.05V but it is really 15.6V. After long float charging the cells slowly reach near 4V each. The Float current is simply too small. I'm thinkig about setting the battery capacity higher to increase the charging currents but I'm not sure about this. But I doubt I wouldn't get my battery charged to 4V/cell without float charging. So I'm trying to find out, how bad is this Float charging for Li-Ion packs. I'm following your channel for almost two years and it is great inspiration. Packed with relevant information. Top work.
Here's and idea that might be useful to help the packs from warping or at least hold the Batteries if said pack does warp; and that is to use Zip Ties to close the pack. Long Zip Ties are cheap yet have considerable holding power so at least the Batteries won't fall out. Not sure if you have the room but a few small holes near where the Pack locks onto the Bracket should suffice... With Zip Ties you will be able to close the Open C design and should provide a bit of stability too... Cheers...
That’s quite a good idea. I’ll look to see how I could implement that. The new brackets are holding well for the moment - and temperatures are dropping, but it’s a good idea to have a backup plan.
Adam Welch Belt & braces.
By setting your float and boost recon so low it means there's a window between 4.16 and 3.71v where your solar panels are doing nothing and you are throwing away energy. In reality if you can keep your cells >4V all day that would be best so I would set the recon at 4.00 and the float to something like 4.05
This is an excellent point and has got me thinking. For me I don’t really use the power in the pack during the day - I’m out at work for most of the week. However that isn’t to say I might want to use the power, or I shouldn’t be wasting it. I need to have a think.
Adam Welch Yes, you want to keep the cells topped up while producing power with PV; not drawing the cells down, then reconnecting to charge. In this way, you'll ideally go into the evening with a full bank.
That's what a float charge is ... if your float is 4.05V and your cells are 4.05 then no current from solar will go into the cells... You need a voltage delta to have a current. The problem with his setup is he will cycle his batteries (partially) during the day when he should be capturing solar. Once the boost period is done no power from solar will be used until the batteries drain to 3.71V. In fact that article recommends 4.05V specifically ...Point is if floating your battery to a 90% charge "breaks it" then your battery is worthless. If the only "safe" state is "mostly discharged" that's not very useful. So ya you shouldn't float at 4.20V but floating at 3.7V is kinda pointless too.
edit: boosting to 4.2 and floating at 4.05 also means you will cycle a bit before solar kicks back in which ensures you don't keep the cells at 4.2V all the time but also means that should solar go down you still have a mostly full li-ion cell.
Yup, but you also don't want to keep them fully charged all the time. Boosting to ~4.15V and floating ~4V (and recon at 3.7-4V range) would be best for most random li-ion cells/packs.
You could but that's what a float voltage is... If you take an 18650 that is resting at [say] 3.95V and throw a 3.95V power supply at it 0mA will flow into the battery. When your MPPT is in float mode it's bucking the solar power to the float voltage. So as long as that isn't too low or too close to 100% you should be fine. a float around 4.05V should be fine for any competent li-ion cell.In Adam's (current) setup he's burning energy until the cells hit 3.71V at which point any further draining will charge them to 3.71V. Whereas if he sets it to 4.05V it means he'll burn off the boost charge and then start using solar power again once he uses 10-15% of the capacity (per cell). Then at 4.05V solar will be used (if sufficient) keeping the li-ion mostly charged should the PV go down then turn to the cells.
That kinda pointless since there's no need to keep the cells that low and you're throwing away a lot of solar power in the meantime (depending on the size of the battery array). He should have the boost to 4.15V +/- a couple 10mV and the float ~4.05V. That way he's never fully cycling the cells but also not depleting them needlessly during solar hours.
edit to add: "technically" throwing 3.95V at a cell with a 3.95V charge will put current into the cell due to self-discharge but that rate is so slow for a healthy cell that effectively you're talking micro amps at that point.
Excellent video
Adam, not using CC in your setup is safe because the maximum current the solar panels can generate is below the maximum current eack pack can be safely charged at.
However, it's important to note that if the panels produce more current than the batteries can be safely charged at, they will likely overheat and may cause a fire.
hrm I guess you dont have the float at the 4.1v mark because keeping Li-ion on the charger for a long time can lead to degradation, the problem is is that worse than discharging them deeper since you will be running the loads on battery power as soon as the boost charge was finished? basically it will charge to 4.1v per cell on a normal day with solar running the loads at the same time (power coming from the cells if the sun goes behind a cloud) then when the boost duration is done after 2 hours it will stop using solar and only run on the batteries even if the sun is still out, until it drains to the float voltage at 3.8v per cell. doesnt seem that efficient as far as getting every drop of sun it can. im sure it will probably never get a full 2 hours of boost before the sun goes away but still what if it does? or if you want to run a big load when the battery is full? the power could come from the solar as well as the batteries but instead once it is off boost charge all power will come from the batteries. im sure as long as you are cycling every day it will not degrade the cells by keeping them charged all day.
Hi Adam
10:25 you talk about setting the over volt disconnect to 29.75volt. I have tried to do the same, but the
software in the controller only allows to be set to 29.7 volts ? (5mv in difference)
Did you really set it to 29.75volts ? the same goes for "Charging limits voltage" as 5mv steps is not possible to set.
To answer my own question....It's not possible to change the steps by 5mv in the MT50, only the PC program can change in 5mv steps.
you might consider changing the 15A breaker between the solar charge controller and the solar panels to just an ordinary light switch if you need to repurpose the 15A breaker.
Szia ezek milyen bms-ek?
Excellent! you've done a great job on this. i do hope that it all works out and from what i can tell, it should. someone below suggested printing the mounts in PETG, both PETG and ABS have a higher melting point so they both may stand up to the heat a bit better. I just saw now that someone also suggested one or two 12v computer fans blowing across the battery mounts?
good luck & keep up the great work!
Russ from Coral Springs, Florida, USA.
can you post the designs for the tracer bracket and the wemos ?
Thank you sir. Love to follow your work.
Great little project Adam and a very informative video.
You could break out part of that for a video on epever controller settings. Not much info on setting them up for lithium out there 😁
Make that bit into a separate video? Well those setting might change so perhaps once I have them set I’ll do exactly that - cheers.
How did you find me doing it on paper rather than in the software or on the MT50?
Hello Adam, maybe you can help me with my problem, and I have the Epever Tracer 3210AN on a 4S Li Ion battery system. In battery mode "User" you can set everything from 9-17V and I have a list of values for such a system, unfortunately it does not charge over 15V although I have set Max 16V, basically it is not bad for the battery but there is not enough energy in it. Do you have an idea or the loader can't do it because then this user mode would be pretty pointless. mfg Marco
I’ve not taken anything that high but if your boost and equalise voltages are above 15v then I’d think about your solar - either there isn’t enough to get the size of your battery bank up to that level, or it’s not producing the voltage. It’ll need battery voltage +1volt at least.
The boost and equalisation charges only last for a limited period of time - if you can’t charge your bank up to that target voltage in that period the charge controller will fall back to the float voltage.
Hope that’s helpful.
Adam Welch hmm so solar voltage should be enough, because I have 2 12v modules connected in series and open circuit voltage is 36-40V.
Hello Adam, hope you are well. I could solve my problem with my Tracer AN and the misterious 15V limit. It was the BMS's fault that the charging process should be interrupted in an emergency because I had previously worked with a cheap china pwm loader and I simply needed security. Now the detail of the Tracer AN measures the resistance of a battery and then adjusts itself, but if there is a BMS in between, the resistance of the battery for the tracer is practically infinitely high and he does not know what he has in front of him, then switches the system at 15V depending on the system download regardless of what you have set. today i rebuilt it for the sake of trial and lo and behold, it loads exactly as i want it.
Lg Marco
Marxter Go. Glad you found the issue. Interesting issue!
@@AdamWelchUK www.ebay.de/itm/3S-4S-5S-100A-12V-BMS-Li-ion-LMO-Lithium-Battery-Protection-Circuit-Board/173619538133?_trkparms=ispr%3D1&hash=item286c87e8d5:m:m57AFWhfXaFVmdHBbunhM6w&enc=AQAEAAACUBPxNw%2BVj6nta7CKEs3N0qVJ1RJ2kHJ8g3nnHNvvCYePmnnBax%2B3rZ5xNCSumTRm292NP3yUD4sQl811Yce%2FeYPvbX28g9rQeKhAjqkLwbLBnNDUBdUF6bx38zvhcKd0oEIiVpBJ7nDo%2Fji%2FmiA%2BRE6Xb7OUQKSjPD4SUEIa6mSKhshdZdC8tV6OrLaQ9U3SFCCUzzw5e8dNlZpox2lLr7O2LQgKOiEp4BFPBOBhZ69hqrb3OF0hlXSPRdmhRAL6nspjnIMSmTSd4BpS9CnmOJaC0btWrZv4%2FC4tNyFLqriO3yWR2%2BZFq9UkkxBIX3neBrxafSrkLBW6UMR3GIyRcGUkRNj0lJ5ND2xq7EVa1QxhGLWNZXHpGeKnbkZiiI%2BS%2FlIfv0%2FX21R3m1UQVvN7SOJCr2c%2FmyGxClqWTr8fqAFGFVaSlPoe3PIYh3SnpjkCvig7COZfhSViXJV4UfHso%2Fy8wqqlJDU731hAlR02vuYpa70qS2MCF9XIeN%2FTklFdfxgWlLLX6oYvNUppUUwnx9LCw0i7JgGNY%2Bm4IgW9JFXWL9tFdfqlsHFGoeJibJZM8j0B1JtCCtn%2FxuLBvMY4QIVasUKwdCBDIHDAHAg5UWQ90cI4dUz7fOixnYSOOw3rSS3YTOWSmu9RsncsWCsmbpgpmhJlCTkMCUjl6stQu0K7%2FuAvG8AEjbfh%2Br%2BGer8e393YYbvqYu%2BGS4htrpPmU0CURNynB4iqzNedJlQ%2BJug%2FDpAlsDIz2V70F2MTTHK%2BJgKJfKyWPnRQrEGKIOUYVfM%3D&checksum=173619538133a48dfdad71454fe79342f09465f9712e
this boy was to blame, basically everyone who works on this principle
hi, do you have a link for the wemos bracket? thank you
why not putting 3 or 4 120x120mm pc fans under that shelf to move the air a bit and avoid the heat and the PLA warping?
Sadly the shed isn't insulated and as mentioned by Mai the ambient temperature is high. It's rained already this evening and is notably cooler - I might be safe again until next year now anyway!
Very informative video, thank you.
Can I do this in 12 volts most of the things I want to do need 12 volts.
hi adam each pack is 3.7v connected to series for increase voltage right.
how do you balance each cell in 1 pack using a bms if the bms is for 4 cell. sorry is you have a video covering this is so please le me know the link
You’re right that connecting the packs in series increases the voltage. However I have built a 7 cell BMS for my 7s20p pack. Each module is isolated from each other using the ADUM1250ARZ i2c isolation chip. It allows communication between the modules without a common ground (and prevents a short circuit). I hope that helps.
Price of mppt charger...can u deliver to Pakistan for me please
Adam boa tarde sou Ricardo do Brasil.
Estou carregando um banco de lítio 3 s com o trace igual ao seu.
Mas ele depois de um tempo baixa a tenção dos painéis e desliga o mppt, e com isso fico perdendo produção pode me indicar uma confirmação obrigado.
Print brakets in Abs.
Just question is it worth a money to go solar?? How lont it takes to pay back???
Regards
Hi Adam, wrt CC charging the PV panel peak power should be such that maximum current to the battery is below the allowed charge current. Normally 0.5C for li-ion batteries. In the CV voltage phase the current must be reduced to maintain the maximum battery voltage. (in that case the PV panel is not used optimally and no MPPT is done). I am very curious when you start measuring the charge behavior of the EPEver. I tried the same thing and float charging is not what you want and this stage is forced you can only specify the voltage but you cannot avoid it. Cheers
I have similar questions. CC phase (bulk) and CV phase (bust) are OK for me. But CC produces too much current, CV (bust) ends too early. CV mode ends after 180min, but there is still 3 Amps going into battery. So Float phase has to finish the charging. In my opinion the CC (bulk) phase produces too much current for my battery and the voltage rises too fast. Then CV (bust) phase doesn't have enough time to finish charging. So, is there a way, to limit the current in CC (bulk) phase, or is it only option to connect larger battery?
I think your analysis is completely correct. However when you limit the current in CC (bulk) phase what is the point in buying an MPPT charge controller. The only thing imho you can do is to choose a PV panel that delivers the maximum allowed current during CC charging.
Today I tryed to put smaller value for battery capacity. 10 Ah instead of 20 Ah. I was hoping that EPEver charger would put less Amps in the battery. 0,5C for instance. No luck. Bulk phase (CC) probbably puts all the energy it gets into battery. At least my model Tracer 1215 BN. My test battery is too small (20AH) and the current goes up to 8 Amps. The cells should handle this current. But the voltage is raising too fast in bulk phase, and the battery can't be properly charged throug Bust (CV) phase. I wonder if other models are any different. This data is hard to find.
do you know how to fix the voltage on the load output side? i need exact 12V or 24V .
DC-DC
Hey Adam, great vids. Had probes w commas with my AN through the eLog to my laptop. Don't know if it's the real fix, but I could only get comes if the load function is on. I don't use the load for now so had it default off, no comms, but on fiddling with it, powering all off n on blah blah, noticed I had comms when the load was on (no load attached) but switching off load then comms failed. Or maybe you found a solution since the vid was posted. Good luck with it all anyway ..
Have you thought about printing them in petg ?
I've pretty much only ever printed in PLA - I definitely need to look at something more hardy. Cheers
You can get cheap PETG/ABS from HobbyKing when they have random sales. It works fine for printing battery holders
PLA can only handle 50c. PETG about 80c.
Print PETG with 30mm/s and 240-245c nozzle temp. I print myself brackets for 2 solar panels in PETG just now. But I had to buy a new PEI magnetic Surface for 30€.
hello, i really like your DIY ESP comunication but where can i find the 3d case for it?
It's made for the specific size of the PCB I designed, but I've just uploaded it for you... www.thingiverse.com/thing:3012374
Just amazing
Adam, where would you recommend going to buy a bunch of old 18650s like you have here?
I got a job lot of laptop batteries on eBay. Unfortunately the prices seem to be going up and up. The other option is to go to a local recycler or laptop repair centre and start a conversation. If you go down the eBay route, be sure to carefully look at the images to see exactly what you are buying, research the laptop battery model to gauge age, number of cells and ensure they have 18650s if that’s the route you are going.
hello Adam, very interesting video, I'm trying to build an off grid system with 18650 batteries, and I would have some questions for you: I understand that float mode is not good for lithium batteries but I have not understood how you can avoid the controller enters float mode if during the day I take energy from the batteries (in fact if I take energy from the batteries when the battery voltage reaches the float level the controller enters float mode), or am I wrong?
Did you ever find an answer to this question?
hello Adam, I want to do an off grid, system, can i don that with a pwm charge controller or an mppt charge controller?
Yes you can do it with either. MPPT is the way to go if you have limited space for solar panels, but otherwise PWM is fine, and use the money saved on your controller to buy a larger panel or array.
I HAVE 4 PANEL OF 100 WATTS PANEL AND I HAVE 2 100 AH BATTERY AND AN 2.2 KVA INVERTER BUT I STILL RUN INTO PROBLEM, IF IT IS MY PWM OR MY BATTERIES? BECAUSE MY SYSTEM GOES OFF, EVEN DURING THE DAY.
AND WIRE MY ARRAY BY CONNECT TWO EACH SERIES AND PARRALLEL THEM TO MY PWM CHARGER
Adam
I’m building my own power pack and start to charge with same solar mppt
PAY ATTENTION : when using USER, after cutting with breaker or other power disconnection... this mppt loose settings !!
Did you try this ?
Best
That’s interesting to hear. I have two Tracer As and a Tracer AN. None of them loose the user settings after a disconnect. Perhaps yours is faulty?
Adam Welch !
Thanks it’s helpful to share !
I’ll try again and will let you know if I have same problem again... I’ll try to disconnect solar panel and battery.. to see if...
Adam, you seem to have set the peak and minimum cell voltage to the extremes the specs allow, rather than limits chosen to maximise cell life - if you intend to use this capacity in anger, is this prudent? Also - given the effort expended and the success achieved, do you plan to scale this up to the point you can move towards a solar house vs. a solar shed ?
You’re correct I have set the charge controller close to the limits. I’ll be monitoring my pack closely, and it hope to never get anywhere near the 3v per cell lower limit, but if I need to or something goes wrong, the setting is there. 4.1v per pack is a little higher than the 7s8p pack I have which charges to about 4.05 per cell. After a year, the captivity loss of that pack was very small. The settings aren’t set in stone - actually there is something I need to consider moving forward, and the upper limit is another one.
I’ve no intention of running the house from this or any other pack at the moment though.
Thanks very much for the input.
what do you plan to run from the pack?
I've now been going on two years and still haven't worked that one out, but, now I have far more of a chance, in December I managed to get a mortgagor for a house weee
so I plan to eventually (as fund permit) to set up a set of 12v LED lighting strings through out the house.
and to run my new security camera and DVR from the other pack, as it all runs from 12v.
Sounds like you have a big (and satisfying) project to do - good luck with it. Having a 24 volt pack I can use will be handy with some of the kit in the shed - my 'bench power supply' should work a little more efficiently for example. However I think I need to find an inverter. If I find a nice quiet one I'd like to make sure the shed is fully off grid. My soldering iron (and my power tool charger - but that's another story) are both mains fed at the moment and I'd like that to change.
North of England, you in Newcastle?
Nope. Not quite.
Adam Welch Leeds?
Aye lad ;-)
your just east of me. :)
Bradford, Huddersfield, Halifax?
wich BMS u use
I’m using the diyBMS which I built from Stuart Pittaways design. Have a look at my recent videos for more on that.
I've got a similar system ( imgur.com/a/rhrb6EM ) with my own DIY BMS. For charging I've got an SSR for interrupting the solar input. Once the cells reach 4.1V charging is terminated, and when they drop back down to 4.05V the solar is turned on again.
Looks like a nice system. Thanks for sharing.
Dude message me in private, and i shall let you see the dashboard to my solarmonitor, it is a work in progress but i think you will be impressed.
Three weeks of no rain in the UK? No. I don't believe it.
It will charge quicker thhen you think
Wow full length commercial ad
25degrees Celsius
Print with PETG. Problem solved.
fake.
Talk less and do more dude you talk too much ..!
Mrs W?