Should you be using Lithium-Ion batteries on your FPV drone?

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Buy the GEPRC 6000 mAh 6S battery I'm using in this video at:
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If shopping for a comparable LiIo to replace your LiPo, the best approach is to shop by weight. Look for a LiIo with matching voltage (e.g. 4S vs. 6S) and then find a mAh that is as close in weight as you can. There isn't a lot of variance in the mAh capacity of LiIo cells, so you may not have much selection. Each 18650 cell will be about 3500 mAh at most; each 21700 cell will be about 6000 mAh at most. In most cases, the LiIo pack will be a little heavier than the LiPo it replaces, but will give significantly longer flight time.
Li-Io packs will be either 1P or 2P. Such as "3000 mAh 4S" (this is a 1P) or "3000 mAh 6S2P" (this is a 2P). A 1P pack will be good for up to about 30-40 amps at most. A 2P pack wil lbe good for about 60-80 amps. Make sure to buy a pack that can support the current that suits your expected use.
Finally, be careful NOT to buy packs intended for use with FPV goggles. These packs will cost less, but also have extremely low C-rate and will not be good for flying with.
Shop for Li-Io packs at:
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* iFlight- bit.ly/46WOEmj
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00:00:00 - How can Lithium Ion be 2x the capacity for the same weight?!
00:00:20 - Maybe the specs are lying? No they're not.
00:01:53 - Why did the LiIo do so much better
00:03:05 - How low can LiIo voltage go?
00:04:04 - You need to change Betaflight Low Voltage threshold for LiIo batteries
00:06:13 - What to do if Betaflight mis-calculates the number of cells
00:07:32 - The absolute minimum for THIS PACK is about 2.7 volts
00:09:19 - Have I earned your support today?
00:10:11 - What's the advantage of a LiPo then?
00:12:29 - What are LiIo best at?
00:16:01 - When to choose LiIo vs. LiPo
These two quads use an 18650 cell for power. Are they any good?
HGLRC Rekon 3 - • Fly 15 minutes w/ one ...
Eachine Nano LR3 - • Eachine Nano LR3 prove...

[@GiantAntCowboy]

IMPORTANT: Make sure to calibrate your Current Sensor. The Amp reading is often inaccurate and it’s a very important metric when using Li-Ion packs.

[@3dxyz412]

How accurate is accurate? Which brand of sensor is the most accurate?

[@GiantAntCowboy]

@@3dxyz412 it’s impossible to get perfect because there’s a lot of variables... So I always calibrate my sensor so the Current (Amps) & mAh Used display are slightly higher than actual. This is the safest way to do it. With a couple tries you can usually get it within 5% of actual. Basic Process: Fully Charge a Pack, Fly/Drain it, Note the mAh Used, then Charge the pack & Note the mAh Hours Charged. The difference between the Used & Charged is what needs to be calibrated. Oscar Liang has a good write up in the Calibration Process with the calculation used to set the amount. Note: Also check your Voltage Readings. This is easy & usually pretty accurate, but Current (Amps) always needs to be checked & set.

[@Imakilln]

@@3dxyz412 Every single quad current sensor I've measured has been noticeably out, usually ~10-20% - some worse than others (iflight ESC's especially). The answer is to calibrate your quad so that it generally slightly OVER reads so that you always 'think' you've used a little more than you actually have & to account for Internal resistance losses. If you don't have access to an accurate meter you can 'calibrate' it to what your lipo charger recharges - fly a pack, note the mAh reading, charge, note the mAh reading then adjust current calibration up/down until readings are fairly close. Note charging a battery ALWAYS adds more energy to the pack than you discharge.. This also assumes your charger is accurate which is another story XD

[@Filipniak]

Funny after watching this video this question came up on my mind and I was just about to ask about it here, because that's quite often my main source of information in terms of how much battery I have left. I honestly was pretty sure this measurment is very accurate. Thanks for that advise, now I'll do some tests, especially now when I'm flyng iFlight quad. Thanks guys!

[@GiantAntCowboy]

@@Filipniak yea, most FC/ESC stacks actually give you a calibration number to use in BF; but most people probably never even noticed it, and honestly for most people super accurate Current readings isn’t that important. If you do longer-range flights, and/or use Li-Ion packs, it’s always best to do some calibration checks yourself. Having an accurate number will help you avoid running out of battery, or pulling too much current & frying the battery! Note: Though Current & mAh Used figures are helpful guides, it’s also extremely important to watch Per Cell Voltage because you can judge the true health of the battery by watching the Voltage. Over time batteries get weaker & lose capacity, so if you only focus on mAh Used as a fuel gauge you might get an unpleasant surprise one day!

[@HermyH66]

Li-ion has been the nr.1 choice for long range rigs for years.

[@tkanal1]

My friend is making his own Li-Ion packs from single 21700 battery cells that he is configuring according to his needs for his long range drone. Good thing about it is he can adjust the cell pack shape for the particular drone as he needs and also he can adjust the capacity based on how long he needs to fly...

[@chriscflint]

I have built a number of Li-ion batteries and the problem with the sag on a punch out is the thickness of the wires/connectors that are used, in your batteries case I would think it is flat metal plates spot welded to the batteries and the square area of those plates will make a difference eg. if they have used 10mm wide by 0.15 thick that equals a 1.5mm square wire. To do 20 amps the wire needs to be around 1.84 sq mm. To do 40 amps the square are is 7.9mm. Clearly difficult to achieve. If people want to build their own my recommendation is to use wires soldered to the battery not the flat plates with spot welding.

[@GiantAntCowboy]

Nice to see Bardwell touch on Li-Ion packs. I’ve been flying them exclusively on my 7” quad for years & here’s some additional thoughts: *Warning* Not a Popular Opinion, but Soldered packs perform much better than Spot Welded Packs. The reason: Welding requires the use of metals with High Resistance. Nickel is generally used, but Copper is 4x better at conducting electricity, so you get less sag & batteries stay cooler/last longer. Unfortunately all retail packs use thin nickel strips, so you’ll have to DIY to have copper packs. DIY isn’t hard but takes some basic knowledge & patience so you don’t overheat things… I’ve thought about doing a comparison but retail packs are 2x as expensive as DIY packs. For those curious; here’s a super stressful Li-ion tests in the mountains: kzbin.info/www/bejne/nam2l3dsha1khpI And here’s a very detailed comparison of various li-Ion setups: kzbin.info/www/bejne/qKrRnKuVhL6HfKs Definitely a great “tool in the bag!”

[@PhonesandDronesRepair]

When soldering Li-ion cells you need to be very careful. They're particularly sensitive to heat so you need a good iron with a large tip. The surface of the cells also needs to be prepped well. I would use very high grit sandpaper (1000+) or scotch brite then immediately coat with flux. You also need to solder very quickly, not more than a couple of seconds. -HereComesWhitey ;)

[@dividingbyzerofpv6748]

Sony VTC5D seemed to be the best cell available. Gave up some capacity but gained back amperage available. Tried some larger dimention "high amp" batteries and they proved not worth it.

[@GiantAntCowboy]

@@dividingbyzerofpv6748 my favorites are Molicel, especially the P28a for 18650, or P45b for 21700. Have you tried these?

[@GiantAntCowboy]

@@PhonesandDronesRepair hey bud, 100% accurate. Prep & Time are key. It’s usually takes my two rounds of soldering. Soldered a dozen packs and all turned out great. Glad you mentored this, people must do research and use caution. cheers!

[@alpenfoxvideo7255]

at what voltage do you land your drone? I have a pair of ion packs but i'm still landing them at 3.3v

[@MCsCreations]

Awesome flying and review, Joshua! 😃 Thanks for all the info! Stay safe there with your family! 🖖😊

[@grimmliberty7447]

AWESOME AWARD granted! Best explanation of the difference I have ever seen. Thanks!

[@MJ-bj1gn]

Congrats on the 300k subs, jb. 🎉 16:17 I don't quite agree with your choices. Most Li-Ion packs (4 or 6S1P) have a max discharge rate of 30-40A, depending on if they're using 18650s or 21700s. So even if you never exceed ~60% throttle, you will still hit the 30/40A rating of the battery (meaning that the battery gets hot and damaged). I've noticed that on my 7" when I when I exceed about 50% throttle the battery gets hot. Which is why I only recommend using LiIon packs on very efficient multicopters (like the Rekon line of quads) or on fixed wing aircraft

[@maro0016]

A “popped” one about a year ago, be careful 😉

[@CricketyChris]

8s FTW

[@robert-gille]

@MJ-bj1gn This is a 2P pack, that's why double the amp draw is possible.

[@maro0016]

@@robert-gille I had issues on a rekon 6, with I3 (no GoPro) on a geprc 3000mah 6s pack with original 2blade props. I think I used the pack before about 20 times -> it could’ve been also wear …

[@dividingbyzerofpv6748]

3000mah shows it was a straight 6s1p arrangement, yes tbat is gonna be problematic. 6s2p is the minimum I would want in combination with 7in or 10inch quads. I was very impressed with a 10in using 3115 980kv motors with 6s2p. If built for a pair of 4s2p pacls in series for 8s2p the thing would have outright ripped. That is one of places I left off when I backed off of building 4 years ago

[@TheParadigmShiftTV]

I fly the same GEPRC 6000mAh Li-Ion packs with my Chimera 7 V1 & V2 quads. They're great for long range cruising. They get me up mountains.

[@CorruptName1]

11:30 Although the lion battery is sagging to a lower voltage, it is still less of a sag than a typical lipo if you consider the percent of the usable voltage ranges.

[@robert-gille]

Could've included amp draw on osd after calibration to get an idea of c rate.

[@theshazman]

I make my own 4S Li-Ion packs out of Murata 18650's. Slightly heavier than LiPo 4S but I can fly my 4" with a naked gopro for 25 minutes on a good day. I fly cinematic/exploration and long range so it's perfect for me. 6S Li-Ion on a 7" is absolutely bonkers, I think I got up to 40 minutes in one test flight.. with some juice to spare.

[@ChainsawFPV]

Alright! I'm gonna learn something today!

[@prateekchauhan3104]

Tanks to Joshua, now we know the complete layout of his home. ;)

[@bendixtrinity]

one more thing to watch out for in li-on is the Amp draw/usage.. that punch out is really brave. xD I wont ever do that to my Li-on so thanks for showing it to me.

[@adamtrzaskowski3901]

I use Li-Ion cells in my big EDF jets ;) You can compensate for the voltage drop, by adding more cells (7S instead of 6S, plus a ESC that will handle that), or getting a 15% higher KV motors.

[@dividingbyzerofpv6748]

Lastly. Charge rates. 18650s do not want to see more than a 1C charge rate, some cells even listed .5C. So if you drain a Lithium Ion expect a solid hour or more on the charger to get it back up to full voltage. Even storage is gonna take around 45 min from 2.8-3v

[@SmirkInvestigator]

Totally a li-ion guy. Chill tours and and videography. But I do love a good punchy session. Hypothetically, I didn’t see fitted packs when I looked for them at the time

[@Mupshot]

My first and second builds were based on liIon batteries. But have since moved to lipo packs

[@enjoyyourlife2518]

Thanks so much for all your help . Your a hard working very helpful knowledgeable decent caring son of a gun so 👍 Thanks .

[@showdownz]

One is a lipo and the other a lion. You keep referring to the GepRC as a lipo I'll include two time stamps. The first 0:41 clearly shows the GepRC has 18650 and is lithium Ion as its marked Lion The second 1:53 is Bardwell making the slip of calling the lion a lipo. Its an easy slip to make and I expect later in the video this won't happen but I had already noticed this slip a few times by the 1:53 point. Prompting this note.

[@spartan3299]

In my researched opinion, FalconRad FPV has the finest methods for building quality Li-ion packs. I have been building packs for a couple years, but I wish I had seen his tutorial first. The way he lays out his balanced lead is perfect.

[@Fly_High_FPV]

UpgradeEnergy makes great Li-ions for long range, check out the Dark Lithium or the Botgrinder LongRange Batt

[@WendysNuts4u]

Lithium Ion packs FTW on long range cruising flights! Very nice.

[@jonscot8393]

Only battery I have ever go PUFFY was one of these. So much for the safe ones

[@HennadiyKornev]

Thank you for signing that battery, Man 🥰🗽

[@JoshuaBardwell]

Будь ласка

[@Arek_R.]

When I was a teen in need of money, like 10 years ago, I was making custom LI-ON battery packs like that for forum members from FPV/RC community. But then one guy crashed hard and the whole thing caught on fire and I've stopped doing this to not get myself in some legal trouble. Before that I had plane people tell me they would not need to land to change the battery anymore with my li-on battery and they could fly so long they would land because they get bored or their legs start to hurt, the flight time for planes was like 2-3x longer. I was testing those to be used for FPV quadcopters as well and the results were good for non-racing uses but then I stopped because of the above.

[@PhuckenTacoz]

As someone new to flying fpv even though I've had it for a few years this is my kind if battery. Just want to cruise and learn some cinematic videos

[@inakidb]

I had a Auline 3000mA 4S for my long range Roma L5 and I can get the 2.5 after 25 to 30 min of flight. I think Li-Ion will work different if the drone pulls less current than average 5" free style drone.

[@snviper]

I have those in 6S they are very good.

[@VladVortal]

Thx

[@luastoned]

If your amp reading is somewhat right, you are pulling beyond 100A from a 2P configuration, no 18650 cell is rated at or above 50A. Long range FPV usually does not exceed those ratings so it makes way more sense there.

[@lameandboard]

Ive noticed once you drop below 3volts it starts dropping a lot faster. I try to land around 3v per cell or just below it on lion

[@GiantAntCowboy]

Yea agreed. I’ve found that once it’s at 3v per cell you’ve used 90% of the pack & from there it’s drops very quick.

[@DFEUERMAN]

I agree dude, having made about four packs of 6S. I lost a quad listening to Bardwell 2.5v suggestion. (much love to Bardwell and his awesome work) The quad I lost went from 2.65v to zero in seconds. I think 3v to 2.9v is a safer landing threshold. I start coming home at about 3.35v, maybe sooner, depending on how far I've gone.

[@GiantAntCowboy]

@@DFEUERMAN yea, I always try to land before 3v, I save 3-2.5v for emergencies only. (Though I have drained them right down below 2v in one of my tests. Haha!)

[@DFEUERMAN]

@@GiantAntCowboy Haha, you're lucky the FC voltage regulator was able to handle the low battery voltage. (or did the FC power off?) My quad FC shut off over a cove of water. But the quad was so beat up, I don't miss it much. ✌️🪦 I think the 2.5v max discharge spec that JB keeps mentioning is intended for very light and slow loads like an LED flashlight, not for quadcopters.

[@GiantAntCowboy]

@@DFEUERMAN Yea, watch the end of this test video, kzbin.info/www/bejne/nam2l3dsha1khpI I pushed it as far as it would go… was an awesome test. 🏔️The quad actually survived, but was retired after this test. I used the parts for another build. However what’s really crazy is that I still use this battery pack years later to power my goggles! Molicel P42a cells are amazing, I push them well beyond their limits often.

[@proxemiafpv5746]

Nice video jb. What are the standard voltages for lithium ion batteries? Same as lipo? Minus discharge? For instance.. Full voltage: 4.2 and storage: 3.8? And can run them down let’s say 3.0? If you run it like that is this likely to generate reliability or is this considered abusing it?

[@fpvkabo]

I maxed out my ardupilot 6" to 2.233 v/cell before bringing it down from poshold running (hover test only) for 32min. on a homemade 3s battery using 21700 lion cells.

[@juricakrajacic4810]

This is goldmine. Ty

[@TheWalter777]

your thew best .THX👍👍

[@piranha1337]

Now test a LiFePo4 for the funsies! Generally a comparison of energy density (Wh/kg) and C discharge rating comparison would be so nice!

[@JekleFPV]

Great stuff!

[@kimgudboi]

Hello Mr. Bardwell, Just a newbie question, Planning to buy Nazgul Evoque5 v3, can I onset use Lithium Ion Batt packs on it? or do I need to change some hardware plus the settings? btw love the content! much love from the Phillippines

[@DroneMee]

For LiIon I land at 3.2-3.0v per cell. The last bit down to 2.8-2.5v is like emergency reserve fuel lol. On a GEPRC Mk5 with a 6S 4000mah I get 10+min landing around 3.1v

[@ThomasDoubting5]

I really like this guy because he knows what expensive is .

[@pvenzELP]

There is a certain technique when flying li-ion packs. You want to do small smooth movements on the sticks. I've been able to fly for a good 2 miles on low voltage by keeping the throttle at a set position and making elevation changes with pitch changes. If you try to do aggressive punch outs or quick tight turns you'll just crash. It's better to do long , smooth lines with li-ion.

[@dividingbyzerofpv6748]

Used to be I could take a 6s2p 18650 pack out and get nearly 6-7 minutes of cruising flying out of a 7in or 10in build. 3.0v is the time to be close to home to land while 2.8 is for something wrong and you need another minute to land due to some unexpected nonsense.

[@markfpv22]

Congrats for 300K

[@filipzawadzki]

Li-Ion pack for Mark 5 O3 DC - is it possible? Just for crusing, no hard punches. The battery won't get damage because of current?

[@spaced-mouse]

just gonna throw this out there, for DIY packs, the Molicel P28a 18650 li-ion are great. max continuous discharge rate of 35a!

[@KitePod]

yes 👍🏻… or for bigger packs the Molicel P45B 21700 cells with 4500mAh and 45A continuous discharge

[@scratchymaster]

​@@KitePodexcept p45b is like $9 per cell, & for drones prolly won't work in 1p.

[@ramus9]

Not just great, they’re the best!

[@unything2696]

Question, please help: I got a 6S LiIon Pack, Just Like in the video. But one of the cells is loosing voltage quickly. Can I remove the damaged cell safely? 5S and a little lighter would even be better I think.

[@keithcarpenter5254]

Current draw needs to balanced with battery capacity to get the discharge c rate sensible with lion, thats all. They don't have the ability to dump the same kinds of current as lipos, at least, 18650 sized lions dont. There are some bigger lions that can, but you'll have to go back to 4s.

[@mariokotlar303]

Ah, this must be the reason why DJI Avata has twice the battery efficiency than DJI FPV drone. Great to finally understand it, thanks JB!

[@markfpv22]

Finally the video I needed.

[@dronepilot260rc]

I’m convinced that Bardwell never ages 🎉 been watching for years! Keep up the good work man 😎

[@olavpettersen9465]

He definitely will if you refuse to even click the affiliate links.

[@flaparoundfpv8632]

Can't say the same for that wooden gate structure.

[@fpvlegenda]

im so sorry maybe its a lil annoying but i using lion bats a lot and i have some kind of problems statick Ampers at taking of way to high in my opinion its like 15-20 A at take off moment? and once at my 10 inch it went up to 60(with 5 kg additional weight ) but still kinda ???

[@nicolascaferatta2111]

Hello! As always Thank you for your content. Do you think i can use this in my protek 60 cinelifter?

[@pertificatus5420]

I don’t think he is gonna respond to that

[@wiredforstereo]

So, LIon is better for fixed wings? Lower power output for longer duration.

[@maro0016]

Actually lion packs are typically more prone to “pop” under load/high amp voltage. I had this happen to me once…

[@fp-AvERY]

Omg you are alive! 😂

[@musicvr3368]

Well, he said he will be on a road trip and would not upload for some time. No surprise.

[@fp-AvERY]

Listen someone has to give the man trouble. I know I was just joking around@@musicvr3368

[@pro_key_concept754]

This is really interesting how would these 2 batteries compare to a graphene battery in performance

[@mxracingunlimitedltd7784]

Why no Current/Amp Draw on the OSD? Im curious to see how many Amps this thing is pushing out during those full throttle vertical runs with the fully charged battery. It really did get up there quick and sounded as powerful as Lipo just by ear and how fast it punched up.. Im sure when the Li-ion cells get even better they will have all the advantagesbut without all the slight disadvantages vs a LiPo Battery Pack right now. Also, how is the charging time on this pack? Can it be charged at 1C or maybe even higher?

[@rocketman221projects]

The 6000mAh Geprc pack has a maximum charge rate of 5A or 0.83C. Most of the 18650 and 21700 cells have a recommended charge rate of 1C or less. Some can go higher, but they will get very hot and should use a charger with over temperature cutoff.

[@dividingbyzerofpv6748]

TLDW? Because useable voltage range you can use. But things get spicy on Lithium Ion when you fly below 3.2 volts. Basically better be looking to land, voltage sag is quick. 2.8v dips are right there. Parallel is needed for giving useable current. Higher series like 6s is needed to raise voltage so it helps to lower the current to a reasonable range handled by the parallel cells. Was building 6s2p on in and 10in builds 4+ years ago. Ran 6s4p on 13in Xclass. Planned next up was 8s4p for a 13in that could reasonably rip as well as something much bigger that would have been 6s8p.

[@rafaelm3404]

What about those GNB 70C lihv? A 4500mah is 497g. A 7000mah is 708g. Almost as lightweight as a Li Ion. Are they any good?

[@dimitarnaydenov90]

Nice I will use lion in 2 scenarios: 1Long range mauntaine cruising with simple freestyle, dives, loops ets.... 2 car chase at a track Both with 7 inch What do you think about that?

[@josiahmos5880]

Can one have both in parallel on the same drone to get a middle ground? I.e. Lipo helps with power spikes and li-ion for longer flight time... A small lipo kinda working as a large capacity capacitor?

[@rehepeks]

You could but the low voltage cutoff of a lipo and liion are too far apart. With my liions I usually plan to land at 3.0V per cell, sometimes I end up a bit lower. With lipos I try to land at 3.5 or above to keep them happy. That would be a lot of unused capacity of liion side of your combobattery. Better to just go with a bigger lipo.

[@hateforall4012]

Id love a good long range recommendation form my Chimara pro v2... Im having trouble picking a battery. On top of that I get a few hundred yards across a soy bean field and the video starts cutting out.. DJI O3

[@gus8378]

Where do you get those black rubber bands?

[@JefeDog]

You could potentially make this battery yourself pretty easily, for closer to $80 (just for the cells). I assume that they take six pairs that are in parallel, then put each pair in series, connecting your balance lead to the positive of each pair. You could even use the Samsung 30Q cell and get it done for closer to $60.

[@IVAN_ENT]

Have like 50 lishen 21700 cells left from building my ebike pack ,definitely gonna build a few packs

[@DKNguyen3.1415]

I assume the reason you say that you should pick a Li-ion pack in the same weight range as the LiPo pack is to to account for the lower discharge rating of the Li-Ion? As in: If you don't need extended flight times, don't attempt to reduce weight by going with a Li-ion pack half the weight of the Li-po in an attempt to reduce the weight but keep the same mAh.

[@josgraha]

thank you for the informative comparison, i have been curious about this myself but for whatever reason have not researched this. also thank you for the lovely scenery as always, Boulder is one of my favorite places on earth :). fwiw, the advice i have seen in the rc flight community is to use LI on fixed wing and LiPO on multi-rotor and now I know why. so cool!

[@ArcheantusFPV]

@JoshuaBardwell It seems that some of the performance between LiPo and LiIon packs is due to the operating voltage conditions under load. 3.6v LiPo vs 2.9v LiIon That is roughly 0.7v difference or roughly a 24% difference! If you normally use a 1850 kV motor would using a 2300kV motor compensate for the performance feel for LiIon batteries? Please please take a look into this!

[@JoshuaBardwell]

You could go to higher kv if you wanted, and that would raise the RPM, but keep in mind that you will do the same thing with your fingers by raising the throttle. If the voltage goes down, the thrust and rpm required to fly the quad doesn't change. Basically, that lower voltage is just cutting off the top end, and making your throttle position higher.

[@rehepeks]

@@JoshuaBardwell Maybe its time to revisit the 8S quad with LiIon battery? Try VTC5A cells, a bit less capacity (2600mah per cell) but higher C rating.

[@MykytaErikaikin]

What foam do you use for these DJI goggles 2?

[@redreefbud]

2.2v is low cut off for liion (good cell) molicel p42a 😁 but like 20a per cell output. So need more in parallel to match motor and esc.

[@redreefbud]

I build electric skateboards and scooters 😉 just getting into drones. Have a dji mini 3 pro but saw those supernova motors and had to have a set. So ordered the 2207 1980kv and going for a speedybee master 5 v2 and f7 stack 😁 i think the equal liion would be heavier but last longer in life. Each has their place 😁 beautiful place and keep the great videos coming

[@MarcusFPV]

From the rotor riot starter kits, which quad would you recommend? Mk3, moxy, tanq

[@JoshuaBardwell]

Tanq for its durability.

[@ravenm1165]

what about a 3500mah lithuim, would it be half the weight, how would it fly?

[@Pyromancers]

Maybe some light weight super capacitors could give you the big punches on demand with the 18650s?

[@ronmartin7253]

i accidentally overcharged a rc battery in 2011 and it literally flamed! and it was a hard fire to put out, and smelled horrible too. ....but, this killing-it by under volt, is there physical damage also? i have brought back old phone batteries from under volt using a pulse voltage so their charger will then recognise them again...

[@riddimgxd]

Hey Joshua can you do a video on the logic fpv sim, it’s the realest one out

[@thefatmoop]

There are a lot of built in safety features (and weight) of the cylindrical cells

[@benlay750]

The VTC6 cells in the pack are not high discharge 18650 li-ion. Try a true high discharge li-ion such as Molicel p28a slightly lower capacity but more than double the discharge current.

[@BASSstarlet]

Why aren't there esc's that also take measurements from the balance lead?

[@NeilKagan]

I would like to know what would happen if you use a motor with higher kv like a 4s motor? How good would it punch out?

[@dronepilot260rc]

It doesn’t have the ability to produce the intial burst of energy as a lipo but it will cruise a lot longer

[@aowi7280]

I use 4S1P liions with 2450kv motors. I set the throttle limit to 80% and can still pull more current than the battery is supposed to. Gotta be careful.

[@rehepeks]

The batteries were overloaded with even these motors so a higher kv would draw even more current which would sag the voltage even more and make it less efficient and just generate more heat.

[@dg9bfc]

So. For long range use 18650 or 21700 cells.. And keep it low on the throttle (no punching if not needed).. They are not build for the current..

[@truey90s]

That voltage sag is using 18650 cells. What if they were 21700 instead would that improve its performance??

[@JoshuaBardwell]

Definitely. Larger cells can provide more current.

[@isavv_]

My question is... Does the voltage under load count as minimum voltage? (If you punch out a lipo and falls under 3v/cell, will you damage the battery?)

[@QuickNick2402]

As I understand it, you will damage your Lipo if it falls under ~3V period. So yes, under 3V during a punch out will damage it. At least that's what I've always heard and how I fly my packs

[@lameandboard]

3v is very low for a LIPO. I stop at 3.6 I think or 3.5v per cell average

[@gpaull2]

The rebound voltage after sitting is the important number.

[@isavv_]

@@QuickNick2402 Makes sense! because you are under 3v no matter what.. but there is a debate that the recovery voltage is the most important, that's why I asked.

[@seb-depp]

Very interesting - especially as I want to build a 7". My 6S 1000 mAh LiPos give a a battery warning after less than a minute. Are they done? Around 2 to 2.5 years old...

[@aowi7280]

Probably. See how many mAh you get out (or put back in). It will get less with time.

[@overdosed51]

Even if your lipos were properly stored and not abused while flying, they honestly don't last much longer than 2 years.

[@seb-depp]

@@aowi7280 Great advice. How much percent do you normally drain when flying down to say 3.6 volts? I normally fly to 3.5 or 3.6 so when I disarm I'm at 3.8/storage.... Even those with the battery warning yesterday are back up to 3.8/3.9!

[@seb-depp]

@@overdosed51 Thanks, I'll keep that in mind and check more before flying at a "serious" spot like cliffs...

[@FabioPaulinhoView]

I just build li-on battery for long range on samsung 21700 50S cells, they are better than 18650 vtc6 imo, higher energy density and cheaper, at only 5A less discharge rating

[@dividingbyzerofpv6748]

VTC5D was where I went for better discharge rates. Tried single 4200-4800 range high discharge 21700s long ago and didnt like them, sagged way sooner than the 6s2p 18650s that were 2000mah doubled for a 4k mah pack.

[@KK-ol5ov]

I charged up my lithium pack for my GEPRC Croc 5 today and just wondered about this.

[@DannyFPV04]

Great info man!! Li-ion seems like it could be good for fixed wing aircrafts. Throughs?

[@dronepilot260rc]

For sure, I get over an hr flight time with a 4s 5000 mah li-ion pack 21700 cells on a Nano Talon Evo

[@hweissi]

I got a 2P4S pack in my 2.4m wingspan plane and it works great

[@DannyFPV04]

@@dronepilot260rc where’d you buy one of these from?

[@rehepeks]

For low current draw ones yes. A plane that draws a lot of current - no. Same with quads. Great for long range cruising but crap for racing or freestyle.

[@DannyFPV04]

@@rehepeks awesome. Thank you for the reply!

[@selfish1716]

I stopped using LiPo batteries. I fly long-range (from 5-inch to 10-inch quads) with current Li-ion batteries, such as those with 45 amps per cell, I no longer need LiPos.

[@PhonesandDronesRepair]

I recently built a little 2s li-ion pack for a micro FPV wing of mine believing the increased capacity would give me better flight times over lipo. I was wrong. A friend of mine in California has a working theory that due to a few factors, such as IR, you're best off going with a Lipo battery for sub 30 minute flights, and li-ion for flights over 30 minutes. Plane: LDARC 450x, 1206 5000kv, 4024 prop, 110g dry I was first using 36g 850mah lipos and getting a max flight time of about 17-18 minutes. I then built a 1200mah li-ion pack, with 18350 cells weighing 50g, that flew for about 20-21 minutes. Finally I bought some 1100mah lipos that weigh in at 45g. I'm getting 24 minute flights with those. The problem with the Li-ion pack is that they convert too much energy to heat. And then when the pack gets low on voltage you end up with with a negative feedback loop. The voltage is low which means you have to increase the throttle, which then just sags the pack more.

[@JoshuaBardwell]

If you are hitting the LiOn pack hard enough that it's getting super hot, then I agree. The LiOn pack needs to be used at low enough current draw that it doesn't get too hot.

[@rehepeks]

The negative feedback loop was the issue. You were drawing so much current from the liion that the voltage sagged a lot and that made you draw even more current to keep the power up. Most likely you were past the current at which the batteries are happy and that just transformed a lot of battery juice into heat. If the the weight and capacity difference is so small then indeed there is not much point going with a liion. Maybe a lower kv motor with 3S liion could be useful if the weight is not too much.

[@budoskolok]

I am using the home made 21700 lion pack on a 7 inch tricopter. It is cooll :D If you are gentle it can fly

[@Photonees]

Anyone know 4S XT30 LiIon batteries for 2inch? (lipo is around 600-750mah), but cant find LiIons

[@joltax]

Would Li-On packs also have better performance in cold weather?

[@JoshuaBardwell]

I believe LiPo tend to perform better because they have lower IR.

[@vkuran]

@@JoshuaBardwell actually it depends. For example Molicel p42a or p45b performs pretty good even if it's -23 celsius outside and I was able to fly 15 minutes that is approximately the same flight time in warm weather. LiPo looses a half of capacity and more at the same wether conditions.

[@sweed7777]

Do you think a large capacitor could be added to the pack? To help with sudden high amp needs. Like, with punch out or recoveries.

[@cloudpandarism2627]

nope because that capacitor is able to draw massive amounts of current to recharge. i tested it. makes no difference. what would make a difference is, if you can electrically decouple the capacitor from the pack and have a small PCB onboard charger which limits the current going in the capacitor until its fully charged and same PCB will activate it ONLY on full throttle punches. but to make it useful you need to have a huge capacitor on your quad. bigger than the quad itself i think. interesting idea for sure though... 🤔👍

[@techstuff6829]

There was a guy that made a combo pack with both LiPo for punch and Li-Ion for capacity.

[@rehepeks]

@@techstuff6829 Sounds like a good idea initially but in reality its not so great. Li-Ion cells should be used to a lower voltage to get the full capacity. If in parallel with a lipo then the lowest safe voltage of the lipo becomes limiting. So then you might aswell go with a higher capacity lipo.

[@madladdan]

JB really loving his goggles 2

[@stst8301]

I think that the v2 are better...

[@user-hc9dw9gb5w]

Did you try to combine li + li-po batteries to have both good throttle and long flight time?

[@JoshuaBardwell]

You can't do that because they don't have the same voltage range. When the LiIo went below 3.0 volts, the LiPo would be damaged.

[@user-hc9dw9gb5w]

@@JoshuaBardwell I mean not these exact batteries. Some others, whose voltage ranges are compatible with each other.

[@jdnic1]

I built an ultra light 5 inch that can pull 6amps when cruising And the voltage sag is almost non existent. When using lithium ion. This is because at %15 battery, the cells can still provide more than 5 amps. You can harness more out of a li-ion cell with a less piwer hungry quad. But you can double the c rating and amp output by putting it in parallel. 2s6p batteries is basically two 6s battery in parallel. So if you have 21700 baterry rated for 25a, at 2p setup you get 50a. At the cost of double the weight ofcourse.

[@sticky_ricebowl]

"this area under the curve" I got ptsd for a moment. Im still taking my engineering course and I heard something way too familiar

[@DKNguyen3.1415]

I think lithium-ion is also not as picky about state of charge in storage. More usage cycles in that sense.

[@TheJohanJonker]

Also remember 18650 charge time might be 3x more than a Lipo battery

[@neutronpcxt372]

In what universe can a VTC6 pack do 15C sustainably?

[@JoshuaBardwell]

Battery C ratings are always bullshit in FPV.