I once built an ultralight model with a 800mah lipo and a tiny motor. The flight lasted over an hour and the fun became the guessing game of when the battery will die
Very true, but I think what made it tedious was that he wasn't playing. He was just making simple figure eights over and over and over.. which became very monotonous. If was with a bunch of friends playing games or what ever, an hour would have flown by in 10 mins flat lol
Wendler?! Egal xD for all which dont understand this joke, the wendler is a german promi and a meme because the Made a Song named "egal" and egal means it doesnt matters... and this is a Meme
Not for three hours. A battery rated at 3ah with a 1c discharge rate can supply 3 amps for 1 hour. With a 10c discharge rate, it can supply 30amps for a tenth of an hour, or 6 minutes.
Don't know if your are still interested but lithium ion has now become the norm for long range fpv flights. My plane can travell around 100km on one homemade pack its incredible
You mention about spot welders being expensive in the UK. But that's why I'm always so amazed with your channel... You're in the UK, but you don't let that hinder your creative and inventive mind. It's really admirable. I often see American youtubers with easy access to large power tools, large cheap professional garages, less restrictions on buying chemicals. The US is a country where people have more freedom to pursue things. The UK by comparison... You can't even easily get hold of dry ice, or caustic soda, borax, etc. And we're lucky if we have a small shed to work in. But the fact that you don't give up, and don't let the loony laws, prices, and restrictions hinder you is inspiring to me. Great work, keep it up.
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Lithium ion and a little supercapacitor for turbo mode stuff.
super caps are not worth it i think it would be fun to mess around with maybe fore like a drag car but not for anything else really better to just keep extra range unless your building a race plane
@@popinmo so what about a lithium ion powered plane with some super capacitors for short boost in performance, then just charge them right back up during normal flight
@@matthewwilcox2055 yea you can but that may be fun but it I doubt other cons make it not worth it but I mean I guess I think it would be more fun for a car and more practical for a car as then it can have huge huge huge speed boost and not.damage the battery
@@therealpanse Daniel used a normal lipo so it's probably going to last only a few hours at night but already being able to fly all day is going to defeat a simple li-ion cell like in this build. You could try to combine li-ion cells and solar panels to basically have a suborbital pseudo satellite.
@@safetyinstructor (sorry for replying to an old thread) but a good old combustion engine would probably be best for this task! Little 12cc nitro engine and a massive 2 litre fuel tank, if my 1am quick maths aren’t broken, it should be good for about 2000 miles 😅
generally you can discharge Li-ion to 2.5V without really damaging them (and even lower) but 2.8V ish is recommended for longer life and the ideal range of voltage for a Li-Ion is around 3(low) -4V (max)
One thing that sprung to mind as you were talking about the difference in internal resistance between the packs is that the internal resistance of a cell is no different than any other resistance; it dissipates power proportional to the square of the current, so the higher the drain, the better the li-po should perform relative to the 18650s. Since the draw was quite low in this test this may not be a significant factor, but I thought it was worth mentioning.
Hi Tom. I enjoy your channel. I experimented with long duration flight around 1995. I used a small sailplane with a 1.5 meter span, a 6 cell 800 mah NiCd pack and was able to fly for almost 90 minutes. The energy stored was 8.6 watt hours and my average draw was about 4 watts to sustain level flight. Prop was a Robbe 6x3.5 folder and motor was a Graupner Speed 400. I don't remember which wind I used. Average current was about half an amp. I had to do this just before sunset when thermal activity was nonexistent and no wind. I found that trying to climb more than the minimum required to stay airborne shortened flight duration and thermals are bad because there is a lot more down air than up air. Even a little down air increases your average watts. Lipo batteries of even the poorest quality would give around four times the duration. I would have had to worry about the transmitter batteries and bladder control issues with 6 hour duration flights not to mention being bored out of my mind.
@yaimem The answer is in the previous post. Still air and slow speeds with power level set to barely climb when flying straight and level. Turns would give slight loss of altitude. An 800mah 7.2V NiCd holds 5.76 watt hours. Not sure where the 8.6 wh came from in the previous post. A 4 watt draw would last 1.44 hours or about 86 minutes.
one motor, one ESC, no board, cheap homemade 'frame' - over 30 minutes flight time. that's why I love RC planes way more than quads. ok, you need servos but they're just so cheap.
The one thing I love about quads is their resilience. I have a cheap storebought quad that is indestructible. A fall from terminal velocity barely damages it. And the differential thrust deals with any misalignment in weight or rotor condition(i.e. beat to hell). I still would love a RC plane, but I can't afford one right now.
@@ERPP8 I second this... but you do need twice as many props when you crash (on average).I built a quad copter two years ago, the frame is carbon fiber 4mm, I literally plowed the ground with it , bent 1 prop, I bent it back to shape, don't do that, kids( it shattered mid flight and slashed my knee when it fell), I have pictures with it swinging some long grass is caught
@@mortache you'll be happy to know that that's what I did. I made one out of insulation foam and fiberglass. It's a chunky boi with a 3ft wingspan. Not too dissimilar so the one on this video. I just need to make for props for it(I mold them off an existing prop with fiberglass).
@@XYZPlayers correct. The wording should have been Energy Density By Mass but that would just be pedantic when the statement was perfectly understandable already.
I experimented with two red Li-ion in the stranded sires tow get 7.4 volts, the plane had a 20 Amp ESC running a E Max 7 to 9 volt motor with a 6 by 4 prop, it seemed heavy as the model had a tough time gaining altitude, but it was fine in terms of flight, thank you for cracking all the math and enduring the boring 40 min flights to present this video, I will appreciate the next time I decide to use a Lithium Ion batter in one of my planes
Lithium-ion = lithium-polymer. The chemistry is one and the same. "Lithium-polymer" is just short for 'lithium-ion in a polymer package', referring to the plastic ("polymer") soft pouch or rigid box that forms the outside of the cell, as can be seen on nearly all rectangular batteries of this chemistry. (Therefore, "lithium-polymer" is nearly synonymous with "prismatic lithium-ion cell". I do have one rectangular cell (from an old smartphone) that has a metal shell, but it's very much the exception.) It's actually common to make 18650s by first making really thin rectangular cells (in plastic pouches, therefore "lithium-polymer"), rolling them up into cylinders, and putting those rolled-up plastic-cased cells into metal outer shells. Therefore, while individual cells' specs may vary (like the LG ones in the video), the distinction between two categories of "lithium-ion" and "lithium-polymer" is meaningless.
Just for the craic of it, I alo made a 2S2P pack out of 18650's, tested it on my 9inch quad, it flies for about 10 min straight... Also converted all my drills to Li-Ion with the appropriate BMS boards. Just soldering these is a bit tricky. Nice one Tom!!
The 18650 can be discharged down to 3.2v. You literally only used half its capacity! The lipo cell was coming to the end of its capacity based on its voltage...
Except that they can't safely go down to 2v per cell. 3.2v is the lowest voltage an 18650 cell of this chemistry should be discharged to. There is really no usable capacity below that voltage. The LiPos are similar, but each has a different discharge curve.
The first 5 sites that i checked shows the LG 18650HG2 discharge voltage to be 2.5v/cell. The Sanyo 18650GA that I have been using also spec'ed at 2.5v/cell.
Usual high standard, good work. Note, us older guys find long power tests less boring ? with APM and Failsafe set to Batt,Voltage Yes I have been supprised once or twice to hear my plane above me ! but not bored ;-)
For fucks sake they are not all the same thing, 18650 just means what the damn size is. You need to look up your specific battery technical info before you blow some shit up.
There is also one more thing you need to consider. The charging board for the Lipo also controls the discharge rate of the battery. So even if the flight electronics asked for more power, the board will limit it. This is needed to keep the battery from what I call thermal decay aka an over drawn battery ready to explode due to heat.
Lithium Polymer batteries used in hobby RC do *not* have a protection circuit like on Lithium Ion cells used in laptops. Not all Lithium Ion cells are protected, either. That's what makes RC use possible, while also dangerous. The battery will put out as much power as physically possible--even to the point of bursting into flames due to the ESR heating up the pack. Most RC electronics have motor speed controllers with a built-in Battery Eliminator Circuit (BEC) that limits max amperage draw and shuts off the system when it reaches a safe low voltage. The BEC is for sending 5v to servos, receivers, and flight logic boards. All of these devices work together to prevent a battery from bursting to flames.
Great informative video Tom, thanks! You point out the li-ion weight/energy ratio is superior but the current draw is the systems drawback. How about adding a capacitor to increase available voltage/amperage for short bursts of acceleration with the li-ion? Or even using an extra cell and dropping the volts to increase amps?
It would be awesome to retest this new high amperage 21700 batteries. Samsung 30T for example have high capacity and can handle "high" current so they will have a lot more flight time per mAh than those LG HG2. I have tested this vaping and the difference is HUGE.
i'm pretty sure that all them squirrel passengers inside the big body box would not mind. Lessening the spikes on those cells would improve lifetime and so on, if can be done cheaply, regarding weight. Those supercaps were kinda low voltage, need quite many i think..
Solar Function the ir know as internal resistance is the problem it is how much the battery resists the the output and it steadily does that as the more you drain a battery and as a ion it's alot easier to get a higher ir
I made the same observation with my electric bike. I first bought a li ion because it has more capacity but I always had cut off problems. I then bought a li po with a lower capacity but it was much better. Nice video
I’ve had some success from hybrids. You run a strong lipo in parallel with your LiIon pack. You get most of the punch of a lipo, and the capacity of 18650. The down side is you can’t take the pack below 3v or so for long periods of time.
You have to add weight to the lighter battery in order to compare in equal conditions their capacity. Unless you are testing only time in flight. Nice channel, congrats.
I understand laziness. It’s my natural state. But if I’m trying to prove somebody wrong or demonstrate something that almost nobody else knows, I will die of exposure/exhaustion before I quit.
what i have recently noticed is sometimes there is a "security" circuit in the batteries which limits the current so this is why sometimes the tests are not very precise when you compare different batteries etc. because you look at the volatage and capasity and you think hmm it should be the same but it is not but not because of the battery itself...
I have an old 6v cordless drill that I took the old NiMH batteries out of and replaced with two lithium cells. I wired them with a 3 pole switch so I could have them in parallel to charge and in series to power the two stage trigger in use. It works well, as when I store it I can have the two cells linked together to balance them automatically even when they're not on the charger. It's probably shortening the life of the cells, but they weren't the best to begin with. It was just a proof of concept that's worked out better than expected and so I use it.
You should have known the battery specs before purchasing and definitely should have know their specs before direct soldering them. I digress as I have done worse. The main point I wanted to make is that you can get pre-made packs for very reasonable pricing. I got a 7.0AH 3s pack with an xt60 and balance plug for under $50. Much safer and nearly the same price as making it yourself. I highly recommend getting a 2s 18650ga pack for your fatshark goggles. I'm getting over 4 hours with a True-D v3 module in my dominator 3s with DVR recording.
Li-Po is Lithium Ion. It's technically called Lithium Ion polymer. The difference is basically that polymer is flexible, Li-ion is not, and they have some different aging qualities. But Li-Po and Li-Ion can both be manufacturered to be high energy density or high amperage capacity or in same cases both. Your Li-Po batteries here are designed for high amp draw, where the Li-ion you used here are designed for capacity.
Don't know about your country but this would be illegal in UK. Have to monitor the flight and control as necessary to avoid manned aircraft. Flying FPV without a 'spotter' with you is illegal too, for the same reason.
Man the HE2 is a classic but with 18650 everyone started using Samsung 30Q as a balance standard or high drain vape class Sony VTC6 or crazy high capacity Sanyo GA cells for low amps. Glad you tested the difference but I do hope one day you'll just run a joyride with these proper new cells
The Bearospace guys did a lot of interesting work with 18650 cells. Apparently, the benefit manifests more at higher capacities, so running dozens of 18650 cells in a 3S12P or so battery gives a huge advantage in energy density compared to LiPo packs. On a small scale like this video shows, the lower C rating of even the best 18650 cells becomes a bottleneck. Personally, I'm waiting for Tesla's Gigafactory to start pumping out zillions of their 2170 cells. I bet that'll make for a great endurance flight pack.
LG HG2 cells are amazing. I use them in small fpv plane, micro skyhunter, which using 1300mah lipo can fly for 15min. With 3s cell made of LG HG2 it can fly for 42 minutes, using 2400 mah from battery. This cell can be drained to 2.5v, as stated in documentation. I did very careful tests , and found out it is time for landing when cell reaches 3.3V.(no load) If you fly longer, you will squeeze some more capacity from battery, but voltage drop when opening throttle becomes dramatic and dangerous.
There is a ESC in the plane, and the pilot will increase throttle as voltage drops. If the plane has a flight controller with an airspeed sensor, it will do that automatically.
8V should still drive the motor, but there would definitely be a huge loss in performance. On this setup I would need to increase the throttle throughout the flight to stay in the air. For example, if I were using half throttle at the beginning of the flight, I would most probably be using near full throttle by the end (for the same thrust output)... I think!
It wouldn't necessarily decrees performance it would decrease the power and torque and when I say power I mean the driving capabilitys of the battery's an example of this is if you put a Nimh battery into an rc car that has been using a lipo it will decrease the speed because the mother will not have enough torque and too much resistance to frictions
Back in the days, we usually used geared motors and slower rotating props on electric planes due to the poor energy storage of cadmium cells. Maybe it's a way to use the wider voltage range of the Li-ion without too much performance loss. My 2 cents.
This is future of RC Airplane and copter battery , built is very solid . . . 18650 HG2 3000mAh has current capacity is 25A . . . I used in copter and Airplane . . . Wonderful experience with good flight time, interesting think is we can modify any time 2s to 6s or more with numbers of pack combination . . . . . Thanks for that informative video . . .
Yes flying in circles doing an endurance test is boring... "Lithium Polymer" Batteries are still one form of Li-Ion cell. Merely a different form factor (pouch vs cylindrical cell) - polymer in the [common] name is really a misnomer) Any Li-Ion battery cell can use any type of Lithium chemistry. (Li-Co, Li-Mn, Li-Fe(PO4), Li-Ni-Mn-Co etc etc...without knowing which chemistry is used in example cells limits choice, not all pouch cells are equal, just as not all 18650 cells are either. Interesting demo, So use of these cylindrical cells may be more scale-able than pouch cells (if the power draw and hence thermal changes can be limited/controlled through use of parallel circuits, or active controls). Cell chemistry is always changing and being optimised.
Could you possibly do the test by just putting the plane on a stand and just throttle up? Also, on a side note. I use 18650 batteries for my vape and I usually run them down to 2.8 before charging them up. Once I even ran it down to 2.4 and it charged up fine
This is unsatisfyingly inconclusive. How about at least running the model on the bench drawing the same amps -- you must have a good sense of what that model draws in cruise.
Redoing the test by flying might have been boring, but he could have mounted the motors with a propeller on a bench and ran them down till they reached low min voltage to check out his mathematical theories. It would be a better test actually because both motors could be ran the same rpm for a set time instead of slight variations for wind, cornering and climbing or descending.
I'm kinda late to comment, but there's instructions out there to make a small scale spot welder using parts from disposable film cameras that have flashes. if you go to a shop that developes film, they'll often just give you the old empty (already processed) cameras for free. it uses the capacitor and the battery charging circuit from the flash.
The capacity of the battery is measured down to its designed discharged voltage and not zero volts. This is the voltage the designers have declared it is safe to discharge to and the battery is considered to be discharged or " flat" at this voltage. You can use full capacity down to this voltage. Some batteries have management circuitry to prevent discharge beyond this point to prevent damage.
You can always put an autopilot to the plane and have a drink while it "autoflies", little f3 board with inav and agps antenna will add only 40g to the system and make the experiment much more comparable. Next time you solder the 18650s please make a capacity test before & after, warming the cells so much really do damage the final capacity (at least that's my experience!) I would be glad to watch more videos and those 18650 capabilities, keep rocking!
Lots of lithium-ion cells are different chemicaly but they all share one common thing - lithium, thats why they all are called lithium ion. LiPO is lithium ion polimer cell and electrolyte is different but it is lithium ion. Go do some reading, wiki is on hand
agnius, you're right and wrong, at the same time. Because there are chemistries like LiFePO4, which operate on WAY lower voltages, than other lithium chemistries. Yet you try put them in the same bag.
Both cells are lithium ion. lifepo4 and so on are too. The polymer comes from the plastic pouch the cell is in. The cell you refer to as lithium ion is an ICR or IMR cell. Which stands for (lithium)Ion Cobalt/Manganese Round. You also get polymer lifepos or cobald or manganese in polymer pouch.
PLEASE before doing anything else with 18650 build a tab welder. That is so dangerous. I have had 2 batteries vent on be from soldering and one was a thionyl chloride battery...
I have soldered many Li-ion 18650 cells, never had a problem. I use an 80W iron, clean the cells ends thoroughly and splash solder on to the surface the iron touches the sell but briefly. The wire (as in video) just pressed quickly and positvely onto the end. The all metal casings mean that heat is dissipated very quickly. If you use a typical iron that is ok for sircuits boards etc maybe 18W like my Antex then you'll be there all day trying get the cell hot enough. Be careful handling the iron on the +ve terminal the =ve casing is VERY close. Finally if you are still concerned, don't do it. You can order batteries from retailers who will tab them in any mode you require.
The 2200mAh 18650 types can be soldered without problems, when you work quick. The 3500mAh 10A Samsung types seem to be more delicate, I noticed a loss of capacity after soldering. I recommend to use cold spray to cool down the cells before and after soldering. It's quite cheap and helps to prevent danger or even slight damage to the cells.
18650 batteries are also used in high power devices, such as rechargable power tools, Tesla EVs, led torches, ect. With the right model of battery, they're plenty capable of high drain uses.
Don't believe the claims of 3Ah 18650's. Test them yourself with a dummy load and multimeter(s). Most are much less capacity than the claimed figure - especially the cheap ones. Lithium Polymer batteries are the same technology in a lighter container (plastic bag instead of metal can) so would normally be lighter than Li-Ion providing they both have the same C rating. Normally our model plane batteries have higher C ratings so that we can draw high maximum currents. Higher C rating cells are heavier. Buy the LiPo cells with the lowest C rating you can find; measure the actual capacity of them and the 18650's rather than believe the marketing hype; you'll most likely find that the LiPo's are actually lighter than the same (actual measured capacity) Li-Ions.
The specific 18650's he used in this video, the LG HG2, are legit. I've seen them tested to well over 2900mah, getting pretty close to the claim of 3000. Even better would be if you could get your hands on some Tesla 2170 cells. They're around 32wh/g on the cell level. I doubt any commercially available LiPo cell can match that, though that doesn't necessarily mean the 2170's are better for model aircraft. The 2170s suffer from a lot more voltage drop for one thing.
You need to source 18650's from a reputable source, especially if you plan to do get many of them. Buying them on Ebay or Amazon from random sellers, you are asking for trouble. I do this for one-offs when performance isn't critical just because it's conveniant to order cells that way. However this application requires high performing cells. Typically what ends up happening is the random ebay/amazon sellers are selling much older 18650's that were manufactured a long time ago (new old stock) and often do not give you cells that are from the same batch if you order a quantity of them. The popular Panasonic 18650's, for instance, all look the same, but over time the capacity of the newer batches has gradually improved. It's actually got upwards to 3.6AH for the latest cells. Older cells were generally under 3AH. The worst part is that there is no real way to tell what generation of NCR18650 you have, most people that review them and buy them do not have means to test the cells they receive and the claims of the product. I have some really old panasonic cells that are in a purple wrapper that have really bad ESR (they actually remind me of shitty xxx-fire cells!) They are 2AH, they are like 8 years old Needless to say, they perform like shit. Sellers generally don't care that the cells they sell are old, have degraded over that time, or care to send you cells that are well matched. If anyone is aware of a reputable distributor of cells, I would love to know! Most of them I'd imagine probably do not want to deal with selling small numbers of cells to individuals.
The bigger problem imo is bootleg rewrapped cells. The chinese are really good at making the cells look legit. So yeah I agree, always deal with reputable source. I usually buy from illumination supply (www.illumn.com) personally, they've been the trusted source for vaping and flashlight enthusiasts for quite a few years.
Not really. Brand names like LG, Samsung, Panasonic deliver 97% to 100% of the rating. You are talking about cheap Chinese batteries that are labelled not by real mAh, but by fake "flashlight mAh" = 5x real mAh.
it is true that lithium cells cannot be fully discharged without damaging them. this is considered in the total capacity of the battery which is way more than what the label says. that 1800mAh is the capacity you can safely use.
You should look into Graphine batteries. 5x the runtime of a Lith, 1/4 the weight, minutes to fully charge. I imagine you may need quite a bankroll to get one, but if you want hardcore, there is your fix. Pretty sure they are currently only available for military use, but there is ALWAYS a way...
Back in 2002 I put electrics and an 830mAh LiIon Qualcomm battery on a Walmart glider and got 40-45 min flights... but that was one underpowered whale. Its amazing how far we have come.
it wasn't flawed, the results were as expected. he just didnt fly the li-ion battery long enough down to its min voltage. so it still proves you can get over an hour flight time with li-ion.
@@crspy914 It WAS flawed, in that he DIDN'T fly it long enough, so it proves absolutely nothing. You can't extrapolate from this and say it WOULD have gotten over an hour. If you could, then there wouldn't be any need for the test, you could just calculate from the specifications. But the whole point of tests is that you can't just trust the specs to be correct for your application. Again, total waste of time.
@BrightBlueJim, Myself including 142K of Toms subscribers all agree that he has valuable information to share with the community, what the fuck are you doing with your life? All you've accomplished is troll the internet and spread toxicity in our community. Go play fortnite or something, kid.
Yes,,after testing,,you did the math and investigation about the difference, so it's all making sense and no need to bore yourself to death,,we're done,,great video,,thank you.
use a soldering iron at high temp, clean the surfaces properly, and sholder quickly then its OK. I have done dozen of cells that way and they are still working fine after 18 months and many cycles.
You can take any decent lipo down to 3.3v with no problem. 3.7 is the nominal voltage because it's in the *middle* of the operating range of 3.2v - 4.2v. And yeah those LG HG2 cells still have a good amount of juice discharging beyond that usual minimum, but there's little to be gained by discharging beyond about 2.7 (2.5 under 1A load); there's just not many mAh there. That is to say, voltage drops off pretty quickly past that. Running all the way down to 2.0v will also drastically shorten its life.
Lithium polymer batteries are lithium ion ( LIPO ) the P stands for the polymer the pouch that is used. Lithium ion cells are of the same thing except with a metal casing that's why the P is removed there is no polymer pouch. The capacities are different because of the chemistry that is used you can either have high discharge With low capacity or Lower discharge with higher capacity. There essentially the same cell bit different Manufacturing methods and with Slightly different chemistry For higher discharge or higher Capacity.
I think, Li-po is more preferred for the reason that we suck many C rating of current out of it compared to Li-ion. Btw, I always like to watch your research videos. You do great job in your posts for others to learn.
Well of course. 18650s are usually drawn down to 3.2V but you can take them further down to 2.8V (only 3% of energy lies between 3.2V and 2.8V). The 50% level is at 3.65V. So at 3.7V, you still had 55% of the usable energy remaining in the cell! For longevity only charge to 4.125V and discharge to 3.35V. That is about 85% of the capacity.
If LI-ion cells could be discharged to 2 volts per cell, ie 8 volts in total, it would significantly reduce the performance of the plane because the plane would be flying at half of the rated working voltage during the final minutes of the flight. It is always better to have a constant performance and decent flight time than degrading performance and high flight time.
You have to have a look at the specs. A Sony 18650VTC6 for example delivers exactly the rated 3 Ah at 5 A discharge while the Samsung 35E will lose capacity down to 3150 mAh of it’s rated 3500 mAh at those high discharge currents. Both are very good cells but are made for different scenarios. Btw since Li-Ions give much of their capacity way below the rated voltage you have to be sure your electronics work reliably down to 2.5V / cell.
There's another thing you have to put into consideration, man. You should compare the Li-Ion battery pack to a 25C Lipo. Because, from what I know, that's the Li-Ion battery C rating. ;)
Among modern cylindrical Li-Ion cells you'll find different types. There are those commonly used for lights and laptops, high capacity but limited to less than 5A, and have relatively low number of charge/discharge cycles, and those used for high quality power tools, those are lower capacity but can deliver 20-30A of current and have a lot longer life. Unfortunately this seems to be an inherent tradeoff, that is, the combination of capacity and current-handling capability does get very slowly better over time, but you'll always need to choose one or the other. A lot of the recent capacity progress has been down to specialising the cells towards low-current applications. But you know what, maybe you can take care of peak current with some kind of mixed battery design, where a low-current high-capacity battery recharges a high-current low-capacity one, or use a buffer capacitor. Also, just install a BMS (internal balancer) and fly your cylindrical cells down to 12V.
Great video, I really like the plane as well. I would like to see a diy build for that plane because it looks very efficient. It looks similar to the skyhunter and I want to try to make a rc plane like this. It would very great if I can see a build video for that plane or maybe Slighly bigger scale.
I regularly run my LiPos down to 3.2-3.3v with no ill effects. One of my 3 cell ones (Turnigy branded, I got it in 2012)has around 250 cycles on it and it's still working fine. In fact, the EasyGlider I used to use with that battery lasted less than the battery itself... altough I dont know if that tells something good on the battery or something bad on the pilot, haha.
![ละลาย (LALALYE) - DAOU PITTAYA ต้าห์อู๋ พิทยา [OFFICIAL MV]](http://i.ytimg.com/vi/wo6r9TgausI/mqdefault.jpg)
It is amazing that the battery and magnet technology has come so far that flights are so long they are boring.
I once built an ultralight model with a 800mah lipo and a tiny motor. The flight lasted over an hour and the fun became the guessing game of when the battery will die
@Zsavage1 so true
If it's that boring,securing the plane down to something and letting it run down hands free is an option.
@Zsavage1 True
Very true, but I think what made it tedious was that he wasn't playing. He was just making simple figure eights over and over and over.. which became very monotonous.
If was with a bunch of friends playing games or what ever, an hour would have flown by in 10 mins flat lol
If I was going to fly for 30+ minutes, I would bring a lawn chair.
And a drink, with something to listen to...
Plus some popcorn
Plus some newspaper to read
For a test it would be enough to give it a line, a peg and a trim to merrily go round, I suppose (being absolute layman).
Bring everything
I thought he was about to say spot welders are illegal in England...
OI U GOT A LOICENCE FER THAT WELDER
he doesn't know they are
Hey boy, r u up fo doing some SW, the first two is fo free boy, don't tell yo mama.
Wendler?! Egal xD for all which dont understand this joke, the wendler is a german promi and a meme because the Made a Song named "egal" and egal means it doesnt matters... and this is a Meme
@@Philipp-oh4vq what?
Tom, it would be interesting to revisit this in 2020. I would like to see you measure the actual flight time of both to their limits.
I agree, especially with 20700 or 21700 batteries. Samsung 30t 21700 batteries can supply 35 continuous amps at 3000mah
@@YouTookTheRedPill How can it produce 35 continuous amps at 3 amp hours?
Not for three hours. A battery rated at 3ah with a 1c discharge rate can supply 3 amps for 1 hour. With a 10c discharge rate, it can supply 30amps for a tenth of an hour, or 6 minutes.
Don't know if your are still interested but lithium ion has now become the norm for long range fpv flights. My plane can travell around 100km on one homemade pack its incredible
Mount the plane.
You can let it run and if it's a hot day, you've got a fan!
Ronny Ktuziak Bit hes white! He doesnt absorb heat!!
Joking
If the plane isnt moving itll eat more amps than it would while moving and could burn up the motors or overdraw the batteries.
@@thecaptainnoodles What a shitty joke.
@@NeoIsrafil No. It will draw more current that's it.
@@thecaptainnoodles Pathetic joke..
You mention about spot welders being expensive in the UK.
But that's why I'm always so amazed with your channel... You're in the UK, but you don't let that hinder your creative and inventive mind. It's really admirable.
I often see American youtubers with easy access to large power tools, large cheap professional garages, less restrictions on buying chemicals. The US is a country where people have more freedom to pursue things.
The UK by comparison... You can't even easily get hold of dry ice, or caustic soda, borax, etc. And we're lucky if we have a small shed to work in.
But the fact that you don't give up, and don't let the loony laws, prices, and restrictions hinder you is inspiring to me.
Great work, keep it up.
Lithium ion and a little supercapacitor for turbo mode stuff.
super caps are not worth it i think it would be fun to mess around with maybe fore like a drag car but not for anything else really better to just keep extra range unless your building a race plane
@@popinmo so what about a lithium ion powered plane with some super capacitors for short boost in performance, then just charge them right back up during normal flight
@@matthewwilcox2055 yea you can but that may be fun but it I doubt other cons make it not worth it but I mean I guess I think it would be more fun for a car and more practical for a car as then it can have huge huge huge speed boost and not.damage the battery
WEP Caps
or a booster plane module, that falls off when they're spent
Wonder if there some kind of RC plane distance record could try and break.
someone jst did 100 miles🤣
@RC Testflight built a solar plane which can fly all day.
Going to be difficult to beat that.
@@safetyinstructor how about night? 🤔
@@therealpanse
Daniel used a normal lipo so it's probably going to last only a few hours at night but already being able to fly all day is going to defeat a simple li-ion cell like in this build.
You could try to combine li-ion cells and solar panels to basically have a suborbital pseudo satellite.
@@safetyinstructor (sorry for replying to an old thread) but a good old combustion engine would probably be best for this task! Little 12cc nitro engine and a massive 2 litre fuel tank, if my 1am quick maths aren’t broken, it should be good for about 2000 miles 😅
I never knew Tom was a member of the So Cal Surf Club
The test on the shirt was distracting from the video.
I never noticed his attire. It just looked like a generic sweatshirt to me.
@@tristunalekzander5608 your gay and just hiding it
@ no u
I think the spec sheet for Li-On cells shows a 2.7v discharge minimum
generally you can discharge Li-ion to 2.5V without really damaging them (and even lower) but 2.8V ish is recommended for longer life and the ideal range of voltage for a Li-Ion is around 3(low) -4V (max)
One thing that sprung to mind as you were talking about the difference in internal resistance between the packs is that the internal resistance of a cell is no different than any other resistance; it dissipates power proportional to the square of the current, so the higher the drain, the better the li-po should perform relative to the 18650s. Since the draw was quite low in this test this may not be a significant factor, but I thought it was worth mentioning.
Hi Tom. I enjoy your channel. I experimented with long duration flight around 1995. I used a small sailplane with a 1.5 meter span, a 6 cell 800 mah NiCd pack and was able to fly for almost 90 minutes. The energy stored was 8.6 watt hours and my average draw was about 4 watts to sustain level flight. Prop was a Robbe 6x3.5 folder and motor was a Graupner Speed 400. I don't remember which wind I used. Average current was about half an amp. I had to do this just before sunset when thermal activity was nonexistent and no wind. I found that trying to climb more than the minimum required to stay airborne shortened flight duration and thermals are bad because there is a lot more down air than up air. Even a little down air increases your average watts. Lipo batteries of even the poorest quality would give around four times the duration. I would have had to worry about the transmitter batteries and bladder control issues with 6 hour duration flights not to mention being bored out of my mind.
how were u able to fly for 90 mins with just a 800mah pack at 7.2v max? makes no sense...
did u mean 8000mah?
@yaimem The answer is in the previous post. Still air and slow speeds with power level set to barely climb when flying straight and level. Turns would give slight loss of altitude. An 800mah 7.2V NiCd holds 5.76 watt hours. Not sure where the 8.6 wh came from in the previous post. A 4 watt draw would last 1.44 hours or about 86 minutes.
one motor, one ESC, no board, cheap homemade 'frame' - over 30 minutes flight time. that's why I love RC planes way more than quads. ok, you need servos but they're just so cheap.
The one thing I love about quads is their resilience. I have a cheap storebought quad that is indestructible. A fall from terminal velocity barely damages it. And the differential thrust deals with any misalignment in weight or rotor condition(i.e. beat to hell). I still would love a RC plane, but I can't afford one right now.
@@ERPP8 if you have the patience its quite cheap to make rc planes. Sure they dont look like scale models, but they fly and its fun
@@ERPP8 I second this... but you do need twice as many props when you crash (on average).I built a quad copter two years ago, the frame is carbon fiber 4mm, I literally plowed the ground with it , bent 1 prop, I bent it back to shape, don't do that, kids( it shattered mid flight and slashed my knee when it fell), I have pictures with it swinging some long grass is caught
@@mortache you'll be happy to know that that's what I did. I made one out of insulation foam and fiberglass. It's a chunky boi with a 3ft wingspan. Not too dissimilar so the one on this video. I just need to make for props for it(I mold them off an existing prop with fiberglass).
@@ERPP8 i'll just stick with using readymade props. Good props are the most important part of the aircraft. Even cheaper ones will do
"Energy density per mass"
Energy
-----------------
Mass/Mass
Sorry i just had to point that out :)
Energy density could also be of volume hence his specification that its per mass
@@XYZPlayers correct. The wording should have been Energy Density By Mass but that would just be pedantic when the statement was perfectly understandable already.
You can take the batteries down to 3 volts/cell without degredation.
In theory you could even get them down to 0v and they should wake up as long as you baby them on the way back up
Yes, but the plane should be on the ground with nothing running by then. 3.3 let's you land.
I experimented with two red Li-ion in the stranded sires tow get 7.4 volts, the plane had a 20 Amp ESC running a E Max 7 to 9 volt motor with a 6 by 4 prop, it seemed heavy as the model had a tough time gaining altitude, but it was fine in terms of flight, thank you for cracking all the math and enduring the boring 40 min flights to present this video, I will appreciate the next time I decide to use a Lithium Ion batter in one of my planes
Lithium-ion = lithium-polymer. The chemistry is one and the same. "Lithium-polymer" is just short for 'lithium-ion in a polymer package', referring to the plastic ("polymer") soft pouch or rigid box that forms the outside of the cell, as can be seen on nearly all rectangular batteries of this chemistry. (Therefore, "lithium-polymer" is nearly synonymous with "prismatic lithium-ion cell". I do have one rectangular cell (from an old smartphone) that has a metal shell, but it's very much the exception.) It's actually common to make 18650s by first making really thin rectangular cells (in plastic pouches, therefore "lithium-polymer"), rolling them up into cylinders, and putting those rolled-up plastic-cased cells into metal outer shells. Therefore, while individual cells' specs may vary (like the LG ones in the video), the distinction between two categories of "lithium-ion" and "lithium-polymer" is meaningless.
Why do lipo seem to provide more peak output?
I'm actually wondering
Just for the craic of it, I alo made a 2S2P pack out of 18650's, tested it on my 9inch quad, it flies for about 10 min straight... Also converted all my drills to Li-Ion with the appropriate BMS boards. Just soldering these is a bit tricky. Nice one Tom!!
The 18650 can be discharged down to 3.2v. You literally only used half its capacity! The lipo cell was coming to the end of its capacity based on its voltage...
Yeah...he said that in the video
Paul Shuttleworth when?
he said that the hg2 cells can safely go down to 2v/cell. which he should have know about before even purchasing the batteries.
Except that they can't safely go down to 2v per cell. 3.2v is the lowest voltage an 18650 cell of this chemistry should be discharged to. There is really no usable capacity below that voltage. The LiPos are similar, but each has a different discharge curve.
The first 5 sites that i checked shows the LG 18650HG2 discharge voltage to be 2.5v/cell. The Sanyo 18650GA that I have been using also spec'ed at 2.5v/cell.
Usual high standard, good work.
Note, us older guys find long power tests less boring ? with APM and Failsafe set to Batt,Voltage
Yes I have been supprised once or twice to hear my plane above me ! but not bored ;-)
Hehehe I laughed my ass of when you said "Incredibly Boring" cause it's so so True 😂 Nice video
Boy make a spot welder from super capacitor :D
THAT is a pretty sweet hoody.
so important to have a sweet hoody
Lol hollister
18650 can run down to 3.2 volts and recover fine and if you ever want some spot welding done give me a shout .
Barrybados©. Actually, it can run down to 2.5v. That's the cut off of most BMSs (like the one on notebook batteries).
For fucks sake they are not all the same thing, 18650 just means what the damn size is. You need to look up your specific battery technical info before you blow some shit up.
MsSomeonenew Did you ever done that? Try it. Never saw one that didn't said 2~2.5v as minimum.
I'd love to see this test done again with an automatic voltage regulator.
What is that?
@@edism it’s a automatic voltage regulator.
Bro, you have indirectly solved all the doubts about these which usally can't ask directly ,....thanks one again for such detail explaination.
Great informative video! Why not bench-test both battery systems so you can leisurely watch youtube videos during the testing :>)
well it doesnt really work easily. How to verify that the motor has enough thrust always? not as easy as it sounds
Thanks for the extensive test. I use li Ion cells for my model cars. Work like a charm !
I've always wondered about this, thanks for the video!
There is also one more thing you need to consider. The charging board for the Lipo also controls the discharge rate of the battery. So even if the flight electronics asked for more power, the board will limit it. This is needed to keep the battery from what I call thermal decay aka an over drawn battery ready to explode due to heat.
Lithium Polymer batteries used in hobby RC do *not* have a protection circuit like on Lithium Ion cells used in laptops. Not all Lithium Ion cells are protected, either. That's what makes RC use possible, while also dangerous. The battery will put out as much power as physically possible--even to the point of bursting into flames due to the ESR heating up the pack. Most RC electronics have motor speed controllers with a built-in Battery Eliminator Circuit (BEC) that limits max amperage draw and shuts off the system when it reaches a safe low voltage. The BEC is for sending 5v to servos, receivers, and flight logic boards. All of these devices work together to prevent a battery from bursting to flames.
Great informative video Tom, thanks! You point out the li-ion weight/energy ratio is superior but the current draw is the systems drawback. How about adding a capacitor to increase available voltage/amperage for short bursts of acceleration with the li-ion? Or even using an extra cell and dropping the volts to increase amps?
It would be awesome to retest this new high amperage 21700 batteries. Samsung 30T for example have high capacity and can handle "high" current so they will have a lot more flight time per mAh than those LG HG2. I have tested this vaping and the difference is HUGE.
Tom, you could add Super Capacitors with the Lithium Ion to boost the current output if that is a problem.
Solar Function what about the massive increase in volume?
i'm pretty sure that all them squirrel passengers inside the big body box would not mind. Lessening the spikes on those cells would improve lifetime and so on, if can be done cheaply, regarding weight. Those supercaps were kinda low voltage, need quite many i think..
Solar Function the ir know as internal resistance is the problem it is how much the battery resists the the output and it steadily does that as the more you drain a battery and as a ion it's alot easier to get a higher ir
I made the same observation with my electric bike. I first bought a li ion because it has more capacity but I always had cut off problems. I then bought a li po with a lower capacity but it was much better.
Nice video
I’ve had some success from hybrids. You run a strong lipo in parallel with your LiIon pack. You get most of the punch of a lipo, and the capacity of 18650. The down side is you can’t take the pack below 3v or so for long periods of time.
You have to add weight to the lighter battery in order to compare in equal conditions their capacity. Unless you are testing only time in flight. Nice channel, congrats.
I wanted just to know the difference between the capacity, he could just read the manufactures informations
But their difference in weight is part of their important characteristic for a plane... it shouldn't be factored out.
2022 Tom would probably have programmed an autopilot to run the test for him.
Do the test again to to prove the point at least down to 2.8 volts per cell which should be safer for those ion cells
"I could continue to investigate the unanswered questions, but I'd find it too boring."
*Massive fail in my opinion.*
Right? I was thinking "You've gotta be kidding me I came here to see you reach an hour and now you're too 'bored' to go for an hour?"
I understand laziness. It’s my natural state. But if I’m trying to prove somebody wrong or demonstrate something that almost nobody else knows, I will die of exposure/exhaustion before I quit.
1:01 Right as you say "powered flight" a fly goes by (using powered flight)... love it
The fusion power core will solve all that when it comes out.
Good luck installing a fusion reactor on an rc plane. Perhaps you need to wait 1000 years for the relese date.😂😂
@@stelic9515 micro fusion reactors 😂
what i have recently noticed is sometimes there is a "security" circuit in the batteries which limits the current so this is why sometimes the tests are not very precise when you compare different batteries etc. because you look at the volatage and capasity and you think hmm it should be the same but it is not but not because of the battery itself...
both are lithium ion chemistry, one is called polymer because its packed in a polymer pouch instead metal cylinder.
Nope that's wrong the lipo is using a polymer as the layer separation.
It is packed in aluminum which is certainly not a polymer
Brilliant video, I use both types of cells with work(cabinet maker) and RC (race cars) Really enjoyed the comparison.
Hey Tom,
This stuff is cool but I would love to see more rc heli flying like the good old days providing you still have your TRex 700E.
Pete.
I have an old 6v cordless drill that I took the old NiMH batteries out of and replaced with two lithium cells. I wired them with a 3 pole switch so I could have them in parallel to charge and in series to power the two stage trigger in use. It works well, as when I store it I can have the two cells linked together to balance them automatically even when they're not on the charger. It's probably shortening the life of the cells, but they weren't the best to begin with. It was just a proof of concept that's worked out better than expected and so I use it.
You should have known the battery specs before purchasing and definitely should have know their specs before direct soldering them. I digress as I have done worse.
The main point I wanted to make is that you can get pre-made packs for very reasonable pricing. I got a 7.0AH 3s pack with an xt60 and balance plug for under $50. Much safer and nearly the same price as making it yourself.
I highly recommend getting a 2s 18650ga pack for your fatshark goggles. I'm getting over 4 hours with a True-D v3 module in my dominator 3s with DVR recording.
Where have you gotten those packs for such affordable price?
I got mine from gettitanpower.com
Li-Po is Lithium Ion. It's technically called Lithium Ion polymer. The difference is basically that polymer is flexible, Li-ion is not, and they have some different aging qualities. But Li-Po and Li-Ion can both be manufacturered to be high energy density or high amperage capacity or in same cases both. Your Li-Po batteries here are designed for high amp draw, where the Li-ion you used here are designed for capacity.
Get yourself an autopilot system and just put it in GPS hold. INAV can do this for you for less than 60USD
Don't know about your country but this would be illegal in UK. Have to monitor the flight and control as necessary to avoid manned aircraft.
Flying FPV without a 'spotter' with you is illegal too, for the same reason.
John Goldsmith Everything is illegal in the UK. It is simply assumed.
oleost
Man the HE2 is a classic but with 18650 everyone started using Samsung 30Q as a balance standard or high drain vape class Sony VTC6 or crazy high capacity Sanyo GA cells for low amps.
Glad you tested the difference but I do hope one day you'll just run a joyride with these proper new cells
Redo the test for science! :D
The Bearospace guys did a lot of interesting work with 18650 cells. Apparently, the benefit manifests more at higher capacities, so running dozens of 18650 cells in a 3S12P or so battery gives a huge advantage in energy density compared to LiPo packs. On a small scale like this video shows, the lower C rating of even the best 18650 cells becomes a bottleneck. Personally, I'm waiting for Tesla's Gigafactory to start pumping out zillions of their 2170 cells. I bet that'll make for a great endurance flight pack.
Li-po cutoff at 3.7? I've always heard 3.3.
Yeah, generally 4.1V to 3.3V is considered the conservative. 4.2 to 3.0 is generally the "Nominal" voltage range for lithium polymer.
LG HG2 cells are amazing. I use them in small fpv plane, micro skyhunter, which using 1300mah lipo can fly for 15min.
With 3s cell made of LG HG2 it can fly for 42 minutes, using 2400 mah from battery.
This cell can be drained to 2.5v, as stated in documentation. I did very careful tests , and found out it is time for landing when cell reaches 3.3V.(no load) If you fly longer, you will squeeze some more capacity from battery, but voltage drop when opening throttle becomes dramatic and dangerous.
Wouldn't 8V be too low to drive the motor or is there a voltage regulator in the plane?
There is a ESC in the plane, and the pilot will increase throttle as voltage drops. If the plane has a flight controller with an airspeed sensor, it will do that automatically.
8V should still drive the motor, but there would definitely be a huge loss in performance. On this setup I would need to increase the throttle throughout the flight to stay in the air. For example, if I were using half throttle at the beginning of the flight, I would most probably be using near full throttle by the end (for the same thrust output)... I think!
It wouldn't necessarily decrees performance it would decrease the power and torque and when I say power I mean the driving capabilitys of the battery's an example of this is if you put a Nimh battery into an rc car that has been using a lipo it will decrease the speed because the mother will not have enough torque and too much resistance to frictions
Motor*
Back in the days, we usually used geared motors and slower rotating props on electric planes due to the poor energy storage of cadmium cells. Maybe it's a way to use the wider voltage range of the Li-ion without too much performance loss. My 2 cents.
This is future of RC Airplane and copter battery , built is very solid . . . 18650 HG2 3000mAh has current capacity is 25A . . . I used in copter and Airplane . . . Wonderful experience with good flight time, interesting think is we can modify any time 2s to 6s or more with numbers of pack combination . . . . . Thanks for that informative video . . .
Yes flying in circles doing an endurance test is boring...
"Lithium Polymer" Batteries are still one form of Li-Ion cell.
Merely a different form factor (pouch vs cylindrical cell) - polymer in the [common] name is really a misnomer)
Any Li-Ion battery cell can use any type of Lithium chemistry. (Li-Co, Li-Mn, Li-Fe(PO4), Li-Ni-Mn-Co etc etc...without knowing which chemistry is used in example cells limits choice, not all pouch cells are equal, just as not all 18650 cells are either.
Interesting demo, So use of these cylindrical cells may be more scale-able than pouch cells (if the power draw and hence thermal changes can be limited/controlled through use of parallel circuits, or active controls).
Cell chemistry is always changing and being optimised.
Hey, another guy named Tom who makes his own Li-ion batteries. Nice to meet you. Lol
Could you possibly do the test by just putting the plane on a stand and just throttle up?
Also, on a side note. I use 18650 batteries for my vape and I usually run them down to 2.8 before charging them up. Once I even ran it down to 2.4 and it charged up fine
Specifically using the LG HG2 according to the manufacturer it supports up to 2.0V without losing its useful life
I would LOVE to see you do a video on constructing a simple spot welder using a capacitor bank. Solid core copper wire makes good electrodes for that.
This is unsatisfyingly inconclusive. How about at least running the model on the bench drawing the same amps -- you must have a good sense of what that model draws in cruise.
Redoing the test by flying might have been boring, but he could have mounted the motors with a propeller on a bench and ran them down till they reached low min voltage to check out his mathematical theories. It would be a better test actually because both motors could be ran the same rpm for a set time instead of slight variations for wind, cornering and climbing or descending.
Please verify max flight time and it would be less boring if you posted onboard footage!
He says power flight and a fly passes by showing off his flight skills, nice
Subtitule en español x favor, gracias.
Si
I'm kinda late to comment, but there's instructions out there to make a small scale spot welder using parts from disposable film cameras that have flashes. if you go to a shop that developes film, they'll often just give you the old empty (already processed) cameras for free. it uses the capacitor and the battery charging circuit from the flash.
I like the aircraft, do you have a video with details of it?
Google 'Spectre Twin Boom' by Andrew Newton
The capacity of the battery is measured down to its designed discharged voltage and not zero volts. This is the voltage the designers have declared it is safe to discharge to and the battery is considered to be discharged or " flat" at this voltage. You can use full capacity down to this voltage. Some batteries have management circuitry to prevent discharge beyond this point to prevent damage.
Lithium-Polymer (LIP not actual Lithium polymer) is Lithium-Ion.
You can always put an autopilot to the plane and have a drink while it "autoflies", little f3 board with inav and agps antenna will add only 40g to the system and make the experiment much more comparable.
Next time you solder the 18650s please make a capacity test before & after, warming the cells so much really do damage the final capacity (at least that's my experience!)
I would be glad to watch more videos and those 18650 capabilities, keep rocking!
All lithiums are lithium ion and li-po is lithiums ion
ion 'n polyster
the 18650 cell and our hobby type lipo batteries are in fact chemically different dont be a troll man
Lots of lithium-ion cells are different chemicaly but they all share one common thing - lithium, thats why they all are called lithium ion. LiPO is lithium ion polimer cell and electrolyte is different but it is lithium ion. Go do some reading, wiki is on hand
agnius, you're right and wrong, at the same time. Because there are chemistries like LiFePO4, which operate on WAY lower voltages, than other lithium chemistries. Yet you try put them in the same bag.
Aye, and you too are a Lithiuanian ;]]]
Both cells are lithium ion. lifepo4 and so on are too.
The polymer comes from the plastic pouch the cell is in.
The cell you refer to as lithium ion is an ICR or IMR cell. Which stands for (lithium)Ion Cobalt/Manganese Round.
You also get polymer lifepos or cobald or manganese in polymer pouch.
Round could also mean rechargable. Not 100% sure
PLEASE before doing anything else with 18650 build a tab welder. That is so dangerous. I have had 2 batteries vent on be from soldering and one was a thionyl chloride battery...
I have soldered many Li-ion 18650 cells, never had a problem. I use an 80W iron, clean the cells ends thoroughly and splash solder on to the surface the iron touches the sell but briefly. The wire (as in video) just pressed quickly and positvely onto the end. The all metal casings mean that heat is dissipated very quickly. If you use a typical iron that is ok for sircuits boards etc maybe 18W like my Antex then you'll be there all day trying get the cell hot enough. Be careful handling the iron on the +ve terminal the =ve casing is VERY close. Finally if you are still concerned, don't do it. You can order batteries from retailers who will tab them in any mode you require.
i put mine in the freezer for a few before soldering
What BS, Just do a search for DIY power wall, As long as you are careful, you are fine.
I've soldered maybe over a thousand 18650 cells over the past 3 years, never have I ever faced a problem with it.
The 2200mAh 18650 types can be soldered without problems, when you work quick. The 3500mAh 10A Samsung types seem to be more delicate, I noticed a loss of capacity after soldering. I recommend to use cold spray to cool down the cells before and after soldering. It's quite cheap and helps to prevent danger or even slight damage to the cells.
18650 batteries are also used in high power devices, such as rechargable power tools, Tesla EVs, led torches, ect. With the right model of battery, they're plenty capable of high drain uses.
Hey....Lithium polymer cells ARE Lithium Ion...................
Useful information about Li-ion and LiPo. Thank you Tom.
Don't believe the claims of 3Ah 18650's. Test them yourself with a dummy load and multimeter(s). Most are much less capacity than the claimed figure - especially the cheap ones. Lithium Polymer batteries are the same technology in a lighter container (plastic bag instead of metal can) so would normally be lighter than Li-Ion providing they both have the same C rating. Normally our model plane batteries have higher C ratings so that we can draw high maximum currents. Higher C rating cells are heavier. Buy the LiPo cells with the lowest C rating you can find; measure the actual capacity of them and the 18650's rather than believe the marketing hype; you'll most likely find that the LiPo's are actually lighter than the same (actual measured capacity) Li-Ions.
The lipo batteries used in phones and power banks have a good power density and low C rating, but they are harder to source than 18650s
The specific 18650's he used in this video, the LG HG2, are legit. I've seen them tested to well over 2900mah, getting pretty close to the claim of 3000.
Even better would be if you could get your hands on some Tesla 2170 cells. They're around 32wh/g on the cell level.
I doubt any commercially available LiPo cell can match that, though that doesn't necessarily mean the 2170's are better for model aircraft. The 2170s suffer from a lot more voltage drop for one thing.
You need to source 18650's from a reputable source, especially if you plan to do get many of them. Buying them on Ebay or Amazon from random sellers, you are asking for trouble. I do this for one-offs when performance isn't critical just because it's conveniant to order cells that way. However this application requires high performing cells. Typically what ends up happening is the random ebay/amazon sellers are selling much older 18650's that were manufactured a long time ago (new old stock) and often do not give you cells that are from the same batch if you order a quantity of them. The popular Panasonic 18650's, for instance, all look the same, but over time the capacity of the newer batches has gradually improved. It's actually got upwards to 3.6AH for the latest cells. Older cells were generally under 3AH. The worst part is that there is no real way to tell what generation of NCR18650 you have, most people that review them and buy them do not have means to test the cells they receive and the claims of the product. I have some really old panasonic cells that are in a purple wrapper that have really bad ESR (they actually remind me of shitty xxx-fire cells!) They are 2AH, they are like 8 years old Needless to say, they perform like shit. Sellers generally don't care that the cells they sell are old, have degraded over that time, or care to send you cells that are well matched. If anyone is aware of a reputable distributor of cells, I would love to know! Most of them I'd imagine probably do not want to deal with selling small numbers of cells to individuals.
The bigger problem imo is bootleg rewrapped cells. The chinese are really good at making the cells look legit. So yeah I agree, always deal with reputable source. I usually buy from illumination supply (www.illumn.com) personally, they've been the trusted source for vaping and flashlight enthusiasts for quite a few years.
Not really. Brand names like LG, Samsung, Panasonic deliver 97% to 100% of the rating. You are talking about cheap Chinese batteries that are labelled not by real mAh, but by fake "flashlight mAh" = 5x real mAh.
it is true that lithium cells cannot be fully discharged without damaging them. this is considered in the total capacity of the battery which is way more than what the label says. that 1800mAh is the capacity you can safely use.
You should look into Graphine batteries. 5x the runtime of a Lith, 1/4 the weight, minutes to fully charge. I imagine you may need quite a bankroll to get one, but if you want hardcore, there is your fix. Pretty sure they are currently only available for military use, but there is ALWAYS a way...
You mean GraphENE not GraphINE right?
they are easy to make ,check robert murray smiths channel ,,teaching us all new battery tech that you can make at home...
Back in 2002 I put electrics and an 830mAh LiIon Qualcomm battery on a Walmart glider and got 40-45 min flights... but that was one underpowered whale. Its amazing how far we have come.
So... you showed us a flawed test, then were too lazy to redo it properly. Total waste of time.
it wasn't flawed, the results were as expected. he just didnt fly the li-ion battery long enough down to its min voltage. so it still proves you can get over an hour flight time with li-ion.
@@crspy914 It WAS flawed, in that he DIDN'T fly it long enough, so it proves absolutely nothing. You can't extrapolate from this and say it WOULD have gotten over an hour. If you could, then there wouldn't be any need for the test, you could just calculate from the specifications. But the whole point of tests is that you can't just trust the specs to be correct for your application. Again, total waste of time.
@BrightBlueJim Okay, guy. go do the test yourself instead of wasting my time with your need to be a internet keyboard warrior.
@@crspy914 idiot
@BrightBlueJim, Myself including 142K of Toms subscribers all agree that he has valuable information to share with the community, what the fuck are you doing with your life? All you've accomplished is troll the internet and spread toxicity in our community. Go play fortnite or something, kid.
Yes,,after testing,,you did the math and investigation about the difference, so it's all making sense and no need to bore yourself to death,,we're done,,great video,,thank you.
You probably wrecked your Li-ion batteries by soldering them. Cut them open and see!
use a soldering iron at high temp, clean the surfaces properly, and sholder quickly then its OK. I have done dozen of cells that way and they are still working fine after 18 months and many cycles.
forfengeligfaen: ha ha... well, once you cut them open you're sure that you have wrecked them..
I have solderd more than 1000 18650 bateries after 2 years steel working welllll, sory for bad english
nothing wrong with soldering them, he's just doing it wrong. too large of a wire, and too much heat transfer.
Soldering is not a good idea! Here is why th-cam.com/video/YrqsAGr41uU/w-d-xo.html
You can take any decent lipo down to 3.3v with no problem. 3.7 is the nominal voltage because it's in the *middle* of the operating range of 3.2v - 4.2v. And yeah those LG HG2 cells still have a good amount of juice discharging beyond that usual minimum, but there's little to be gained by discharging beyond about 2.7 (2.5 under 1A load); there's just not many mAh there. That is to say, voltage drops off pretty quickly past that. Running all the way down to 2.0v will also drastically shorten its life.
I get the impression Mr. Stanton, could not be bothered.
You should use an osd that measures mah, so that you can use that to time your flights not the voltage.
Lithium polymer batteries are lithium ion ( LIPO ) the P stands for the polymer the pouch that is used. Lithium ion cells are of the same thing except with a metal casing that's why the P is removed there is no polymer pouch. The capacities are different because of the chemistry that is used you can either have high discharge With low capacity or Lower discharge with higher capacity. There essentially the same cell bit different Manufacturing methods and with Slightly different chemistry For higher discharge or higher Capacity.
I think, Li-po is more preferred for the reason that we suck many C rating of current out of it compared to Li-ion. Btw, I always like to watch your research videos. You do great job in your posts for others to learn.
This is the content I’m here for. But please do another test! You did all the work and got so close. I need to know if it’s really possible.
Well of course. 18650s are usually drawn down to 3.2V but you can take them further down to 2.8V (only 3% of energy lies between 3.2V and 2.8V). The 50% level is at 3.65V. So at 3.7V, you still had 55% of the usable energy remaining in the cell! For longevity only charge to 4.125V and discharge to 3.35V. That is about 85% of the capacity.
Time for an autonomous plane to test out this battery pack!
If LI-ion cells could be discharged to 2 volts per cell, ie 8 volts in total, it would significantly reduce the performance of the plane because the plane would be flying at half of the rated working voltage during the final minutes of the flight. It is always better to have a constant performance and decent flight time than degrading performance and high flight time.
You have to have a look at the specs. A Sony 18650VTC6 for example delivers exactly the rated 3 Ah at 5 A discharge while the Samsung 35E will lose capacity down to 3150 mAh of it’s rated 3500 mAh at those high discharge currents. Both are very good cells but are made for different scenarios. Btw since Li-Ions give much of their capacity way below the rated voltage you have to be sure your electronics work reliably down to 2.5V / cell.
There's another thing you have to put into consideration, man. You should compare the Li-Ion battery pack to a 25C Lipo. Because, from what I know, that's the Li-Ion battery C rating. ;)
Among modern cylindrical Li-Ion cells you'll find different types. There are those commonly used for lights and laptops, high capacity but limited to less than 5A, and have relatively low number of charge/discharge cycles, and those used for high quality power tools, those are lower capacity but can deliver 20-30A of current and have a lot longer life. Unfortunately this seems to be an inherent tradeoff, that is, the combination of capacity and current-handling capability does get very slowly better over time, but you'll always need to choose one or the other. A lot of the recent capacity progress has been down to specialising the cells towards low-current applications.
But you know what, maybe you can take care of peak current with some kind of mixed battery design, where a low-current high-capacity battery recharges a high-current low-capacity one, or use a buffer capacitor.
Also, just install a BMS (internal balancer) and fly your cylindrical cells down to 12V.
Great video, I really like the plane as well. I would like to see a diy build for that plane because it looks very efficient. It looks similar to the skyhunter and I want to try to make a rc plane like this. It would very great if I can see a build video for that plane or maybe Slighly bigger scale.
Use low KV motors with larger propellers. Use 2 blade propellers instead 3 blade ones. And you will get much, much longer flight.
Next project! DIY electronics spot welder! And make your own battery back for an electric vehicle
Verry interesting data bits on batteries 🙂
Excellent Tom thanks. Simply explained and clear. And even better you didn't start the video with "Hey You Tubas! What up guys?" he he...
You can solder li-ion cells with Rose's metal, its melting point is below 100 celsius. And it will double as overheat protection.
I regularly run my LiPos down to 3.2-3.3v with no ill effects. One of my 3 cell ones (Turnigy branded, I got it in 2012)has around 250 cycles on it and it's still working fine. In fact, the EasyGlider I used to use with that battery lasted less than the battery itself... altough I dont know if that tells something good on the battery or something bad on the pilot, haha.