How to TEST 18650 cells (DIY Powerwalls)

[@DennisGentry]

First, I think it's great that you're doing this empirical testing. However, when it comes to temperature, you're doing it wrong. The datasheet is not claiming that the battery temperature will stay under the max temperature under all load and ambient temperatures. It's telling you that you are damaging the battery when you let it exceed that temperature. It is your responsibility to either cool the battery or else stop drawing so much current. It is true that good quality batteries will have low internal resistance and generate less heat at the same power output as worse quality batteries, so there is some correlation between good quality batteries and those that stay cooler, but that's incidental, not a claim of the datasheet. Heat is generally the enemy of batteries, from lead-acid to nickel metal-hydride to lithium. Keep your batteries cool! Good luck!

[@jamisusijarvi646]

True. Also measuring with that thermal camera is not reliable. It doesn't show very accurately correct temperature

[@charlesabrams1927]

@@kernowconnection o

[@AB-these-handles-are-stupid]

I know this is old & excuse the revival, but I was about to comment the same thing. I think the way he is testing the batteries would be ok if he was able to include the +/- with proper statistical deviation process. The thermal though is what saying and the camera doesn't really hold up. It is good to use though for safety if that's all you have, but I wouldn't use the data from it. What he is doing seems to be ok for what he is trying to accomplish. It certainly does not validate or replace the spec sheet data, but it gives a good enough look into what the batteries are capable of and if they are good quality. (SR ChemE Student)

[@AB-these-handles-are-stupid]

Also the current and the potential could be different at different temperatures, but that is fairly common knowledge and I am sure he has looked at that. Using just one discharge I believe isnt enough. I would like to see the data after a couple discharge and cool trials.

[@mjkorhon]

True, that's what the datasheet is trying to tell.

[@honpsu]

Temperature rise depends of your ambient conditions. The temperature spec gives you operational limits you should operate the cells. If the cell surface temperature rises over the spec (for example in ambient 40’C conditions), YOU MUST ACTIVELY COOL THE CELLS during charge/discharge and/or LIMIT the current/loading! 8A discharging is allowed up to the surface temperature limit - it doesn’t mean that the cell would be out of spec. And where’s all comparison of SAFETY and lifetime related? SAFETY CERTIFICATIONS (UL, CE, TÜV, ...), safety devices integrated in the cell and are they really working and preventing fire. Lifecycle cost per Wh is not the same if a cell lasts 50 cycles compared to a cell lasting 2000 cycles, especially in powerwall application.

[@Michael-OBrien]

Additionally, the “operating temperature” specification is not how hot a cell surface should get when discharged or while charging. It is a safety parameter that indicates you should, as previously said, not charge or discharge a cell if it’s surface temperature is beyond the given range without hearing or cooling the cell. The second data sheet you read with test currents and surface temperatures is accurate and is not a “deviation” or a duplicate and inaccurate specification.

[@incandescentwithrage]

No safety tests on the OEM cells, but recommending them for a group buy seems risky. Do they vent correctly under short circuit conditions, or just explode?

[@DoubleMonoLR]

Indeed, for packs of batteries used in tools at least, there is a thermistor to measure the temperature so they can presumably cut the power if they get too hot. I'm guessing lower draw situations just limit the current so it's practically impossible to overheat. That the specs say *-20* to 75 celsius does give it away a bit, that it doesn't mean it's the temperature it will reach in normal operation, but the conditions it can operate under. Batteries at 100 celsius sound rather scary, especially with Lithium Ion.

[@mmReefs]

Jehu, thanks for still wearing the "Power 2 Puerto Rico" shirt. It means a lot for us in the island!!!

[@roberthill4239]

Just be careful they haven't given you the best ones first then diminish the quality later on.

[@Crazy--Clown]

*Yes this is what chonks normally do*

[@程前-k8n]

If battery are OEM It could happen, But when the battery is produce at once, it can't be.

[@TRICHOMETRIST]

Bait n switch

[@fonzren3440]

Crazy Clown that's very racist you just said. Most of stuff you have in your life is all made is China, man. Carefully chose what you pay for. Good stuff never cheap.

[@123benley]

Fonz Ren Sony is Japanese and Samsung is Korean, not Chinese,

[@cmuller1441]

You should never let cells reach those high temperatures. So you have to use a cooling system. The closer to 25C the better. The problem is that those measures are for a single cell in free air. But imagine what happen if you pack many of those together... The problem is that using cells at high temperature generates some internal side chemical reactions (unwanted) that destroy them progressively. So the capacity will drop rapidly over time and may even drop sharply if the electrodes end up being plated / covered by side reaction byproducts blocking normal reactions. Unfortunately evaluating the rate of those reactions is hard to test without very high precision equipment.

[@aljanobin78]

Great video, but I want to note the operating temperature is based on your environment. You are not supposed to allow them to go above 60C not that the cell can't go above that. So in your case you should add more cooling and not allow the cell to go above that temperature.

[@haroldsy5066]

One of the ways I identify or classify a battery to be on the better side is to weigh them. Manufacturers usually decrease the raw materials making them lighter. With the same materials used like both have metal cover and same "mah" capacity, you can now compare them.

[@RonYason]

Just a newbie with the interest with powerwall. really great stuff sir..

[@davidaharris2561]

Meeeee Toooooooo.

[@rokask]

Be careful, young one. Treat a box of batteries as you would a canister of gasoline - both can burn your house down with the same ferocity.

[@vraymond2048]

Sorry to say, I ain't expert on battery, but I think the temperature 10:33 is the "recommended" temperature for the battery to work on, just in case if you expecting to get more energy. i.e. to get the best performance from the battery, Please actively maintain the batteries' temperature between -20°C to 75°C max, recommended to actively (fan) keep battery below 60°C during discharging. Please correct me if there is anything that doesn't make sense to you. Also, you should have test compare their charging cycle limit and degradation rate as well.

[@theone6805]

Milliamp spec, temperatures spec, and short term test of a battery does determine a good battery. It's the quality and long term use determine a good battery

[@dennisyoung4631]

Good. I’m hoping to start doing up my own “emergency suitcase batteries” within the next 18 months, and the same for “monstrous bike batteries.”

[@bro7269]

I do safety testing (short circuit and overcharging) on commercial 18650 and 21700 all day. I would never use any of those cheap cells. I’ve seen too many of them vent (at best), explode (at worst). I would never let them get above 70C on a charge or discharge. Even using good ones, all it takes is one mistake and your house will be gone.

[@stephentaylforth4731]

Quick and dirty - weigh the damn things. Fakes are almost invariably light. Testing is far better obviously but weighing them will catch a lot of crap before you get involved in testing. If you're running a powerwall the IR is often secondary as typical load is usually fairly low per cell. Pulling 10 amps per cell will discharge it in a few minutes. A powerwall that goes flat in 20 minutes isn't much use. It goes without saying don't buy anything with fire in the title......

[@bunnatang2081]

extra cement will make you lift the battery happily.

[@melgibson6331]

I have a trust fire charger ;)

[@robertkubrick3738]

@@melgibson6331 - I have actually seen some anecdotal evidence that non counterfeit trustfires are legit. Not highest quality, but not trash either.

[@davidaharris2561]

I would Check Every ONE anyway if I decide to Build a Power Wall...for Now I'm just Looking for Replacements to My UltraFire 14500 & 18650's for My Flashlights. Any that You would recommend ? I need 10> 14500 and 12. 18650's . Thanks ! I do have a Good LiPO charger(small VENOM Pro) to test Mine with(My 7 year old UltraFire) they have been doing Good, but don't last as long now.

[@gamtax]

I always use this quick and dirty test, until I received a fake powerbank. The cell felt heavy as usual. Once dissected, it filled with sands. Those genius rip-offs...

[@frankbumstead3838]

Well done, interesting that well known Manufacturers are not necessarily the best. I have bought a small number from a UK distributor and so far they Check out OK on capacity after a few cycles through the Charge / Discharge equipment I'm using. Sinowatt 34MP 3350mAh 18650

[@davidbanwell7728]

Thank you you have cleared up a lot of my questions about safe loads on charging Batterys.

[@joeemenaker]

What’s your recommended capacity tester? I didn’t notice a brand/model when you showed your discharge tester.

[@igorfomenko9189]

Revolectrix Dual PowerLab 6 Touch, not the best choice, author has another one because this one gives only 8 amps discharge current

[@choppergirl]

Seems to me of the few batteries you tested, the Samsung INR18650-35E seems to be the winner. You can't say the OEM batteries are the winner price for performance, because without a brand name / company, there is no way we could buy them, so they are automatcially crossed off the list as mystery battery that can not be sourced. fpv.air-war.org

[@LarryLaPine]

Thank you. I am looking to make some e-bike batteries and other projects. Aside from the oe brand of 18650 batteries do you have recommendations as to type and brands of other materials, gauges of lead wires, nickel strips, fish board etc.

[@riteshpatel6823]

Exactly when i was searching the time line for actual test it said "God when is this guy going to show us the actual test".

[@mrcrunch8000]

I can't believe they let you damage $4,000 in batteries. lol. I know this is old so hopefully by now you have learned to properly read the datasheets and test cells while understanding the temperature ratings and conditions.

[@garrettboice3040]

I liked that inception stuff you did with the camera and computer screen. At first I thought the video quality had just dropped markedly.

[@Derpy1969]

Regarding the temps you measured, you need to account for the room temperature and calculate temperature RISE above ambient. Verify what the spec says the ambient temp should be, how much airflow is allowed, and compare to your results.

[@ratgreen]

Hopefully you can ship to the UK. You just have to be careful they dont do the old bait and switch. Send you a few good ones to 'prove' they are good quality, and then sell the lower quality ones once you buy loads.

[@NIEPSEN]

With regard to the physical relationship between the internal resistance, the emitted temperature and the produced current, Re-Volt cells have an internal resistance of 40 mOhm and not 25.

[@nikoladd]

The operating temperature specification is for you to keep it in that range in order for it to perform. It's not something the cell manages. Basically you're using it wrong. You should have cooling for that purpose.

[@2061526]

how to test 18650 battery total capacity without lowering the cut off voltage too much?

[@jozsiolah1435]

Laptop battery pack can fix bad cells by pumping - into the +, if it has to. By making a laptop pcb board, you may be able to fix individual cells, later inserting into other devices, it still works.

[@mikedelcaribe7422]

The last OEM cells you tested work out to about $275/KHW at rated capacity.

[@shaunblack5365]

hi can you let me know where to get the OEM battery from i am in UK thankyou

[@johnnyzee383]

For someone without this sophisticated set up...if you have a cell that is high capacity like 3000 mah..2 things you can do right off the bat...weigh them first..they should come in a about 45 grams..if they come in at 35 grams, alarm bells should begin to ring...next is to measure resistance...if the cell is suppose to have 30 moh and it comes in at 60 then alarm bell no.2 should start ringing...next test capacity.

[@fernando63014]

subtitles in spanish your work is very interesting thanks from peru

[@Zener17]

You should learn about AC-IR for LiB batterys and look into the cole cole graphs.

[@Georges3DPrinters]

Excellent informative video. Only missing longevity, but you actually need to have them longer and actually use them, so I guess your doing that now and I hope it's a good life span. Dod is another thing. I really appreciate your videos.

[@benoittheminerandgamer]

so witch brand is the best?

[@UnrealVideoDuke]

Many times people were given samples of the better quality items and were sold less quality items afterwards. Did you ever check a very good and well known OEM brand Sanyo???

[@teamholmez86]

There are visual ways to tell if you have a fake, you have to take the wrap off but if you look online for certain cells there is a way to tell for some 25rs being one

[@ljprep6250]

Re-Volt looks good, Jehu. So you use the Powerlab6Touch for individual testing, but what were those 4-cell testing units (other than the LiitoKala Engineer Lii500)? Wish I could get in on this group buy, but the property tax people got to me first.

[@sherellucasemmanuelcarsola6896]

newbie here...just want to know with the 18650 batts how is it wired? i mean how many parallel and series? i mean from other youtube videos it says no more than 2 parallel and up to 48v series so im a bit confused bec i see a module here has so many parallel and many series. im really a newbie but willing to learn and will appreciate any clarification ty in advance.

[@rs45888]

You need to make cycle tests.. whether it really keeps performing after x number of cycles.

[@程前-k8n]

It can be really trouble if test it before we actually do the pack

[@goeja]

I have a question? Can you use ebike cells to build power wall? Please can you tell me if its possible?

[@jehugarcia]

Yes

[@goeja]

@@jehugarcia thank you so mutch

[@rohitdalal1929]

Hi, Can you mention the equipment you are using for testing the cells? So that we do not have to google a lot and just get the required tools and start testing? Please!

[@caloycoy6133]

Where did you buy those batteries

[@margeshsanghani4139]

Which one cell is best to buy according to you please named it????

[@Lot_2023]

Makes me wonder. WTF do the quality of the initial cells they sent you............have to do with the quality of the cells they will send you if you start ordering them?

[@bobravenscraft5376]

You have to sample from center of kilo lol

[@MsCripwalk]

How can i test my Cells at home? I dont have those techniques that you have for testing. I use 2 Sony Konion VTC5A for my E-cigarette. I have only a charger that shows Voltage, MAH etc. What do i need to pay attention for? The charger is a Golisi S2

[@maicod]

I wonder if the chinese 18650's that performed so well can be trusted to be of the same quality/specs each time a new batch is ordered

[@程前-k8n]

Only some big company you can trust

[@RoamMeYo]

Since you don't ship them outside US, why not share the seller details of the Chinese OEM?

[@RoamMeYo]

[e-mail] id :/

[@brinkshows2720]

Because then people from the US can also contact them and buy it from the manufacturer and now Jehugarcia won't make any money off they us people

[@RoamMeYo]

Details? hell yeah!

[@jehugarcia]

We are shipping to most countries, no legit excuse to try and circumvent me

[@jehugarcia]

That’s why we have gone straight to the factory

[@kowalskey007]

You are good man and I think you should charge them and keep them in good wentilated spare room ...for your health Mate

[@mujtabaahmedkhanjan8341]

can you guide me about Internal resistance of 18650, low is good for laptop battery or +60 is good? and with is maximum and minimum resistance of 18650 cells for used cells in a battery

[@NexiTech]

Great video and very useful info! Thanks. Keep the great work

[@motherjoon]

PCB mount XT-90s are not widely available. There are some on Ali Express but thats it.

[@legominimovieproductions]

One question: when i take bat-packs apart, they plastic around the 18650s often has glue on it or gets destroyed, how do you prevent it? and more important, how do you get the spot-welded ends of the batterys clean and so that they dont oxidise?

[@antidecepticon]

You don need anything fancy at all to charge batteries its all standardised and the chips are cheap as dirt. MCP73831T-2ACI/OT - LI-ION/LI-POLY CHARGE CONTROLLER its 72 cents. a cheap charger may be risky but if you can open it up and see if its using industry standard parts .

[@racerx1508]

Where is the best place to get 18 650 batteries for vaping

[@maximemineault8117]

I do not think the operating temperature is what the maximum temp the battery will get. I think the operating temperature is the range of temperature that you can actually charge and discharge them. If they write max 60 celcius, I think it mean that it is not suggested to charge or discharge it at any load if the outside temperature is more than 60. What do you think?

[@peterzingler6221]

Um the Operation temp is set by a test in the factory that shows how hot the battery gets if the maximum current rating is used over the entire capacity of the cell:)

[@NilsStinnesbeck]

@@peterzingler6221 No. That is exactly not what it is. It is exactly as some people already said the range of temperatures in which the manufacturer "guarantees" it's product to work in. For more you can also read en.wikipedia.org/wiki/Operating_temperature

[@MINDLE55EMPIRE]

This really helped

[@aaroncatolico7550]

*So which Chinese batteries are credible & for the best price? What do you recommend?*

[@E85_STI]

I found some 18650 cells on 18650batterystore and the cells that are available are Samsung 25R 18650 2500mAh 20A Battery. Would these be ok to build a 12v 10AH battery pack for an icy breeze that draws 4amps? I know it says 20A but I’ve seen the 30A 20S Samsung cells all sold out so I’m wondering if these would be strong enough to power the icy breeze or a power wheels truck? Are they high drain type that will work for those types of applications?

[@caserio323]

jehu!!! Me encanta los potes de pastillas de la mesa donde estas enseñando las baterias lol ya veo de donde biene la inpiracion para trabajar lol yo se que tienes un tick nervioso que sentado no paras de brincar pero trankilo nadie es perfecto yo soy igual bueno sigue tu trallecto para el nuevo futuro papa. saludos de su amigo de la internet Hector

[@ZillionPrey]

English would be appreciated

[@caserio323]

google translate

[@ljprep6250]

Jehu, have you checked with Re-Volt yet to make sure they =don't= use the bad Ni-Rich NCM cathodes in their batteries, or have you torn one down?

[@aceseightsazhvacsparkyandg8138]

Ok how do I get info on buying the OEM batteries?

[@igorberezin856]

Have you come across an ISR18650 cell? they seem to have been used in cao mm ebay ebike batteries. know anything about those?

[@typingcat]

Which of the following would you prefer? A. a puppy; B. a flower from your sweetie; or C. a large, properly labelled boxes of new batteries?

[@Broxine]

Awesome tests. thanks

[@MP-zf7kg]

I wonder....I got a pack of 39 cells that I feel is grossly underweight, maybe 49 oz vs what I'd think should probably be at least 64 oz. Seems like if you have a cell or group of cells that seem underweight, they might be junk? My conjecture is a typical 18650 is 1.7 oz.

[@wes1550]

I just got a LiitoKala charger and some LG 2200Mah modem cells. The modem cells tested great. I just got a couple of dozen NEW INR18650-35E 3500mAh 13A for DIY phone chargers. The cells only are testing out at about 1500 mAh discharging at 1000mA. The tests are cutting off at about 3.5 to 3.8V when the charger says cutoff is 2.8 V at 500mA. Are these fake cells?

[@lyfandeth]

Now, can you trust the no-name supplier who sent you great samples for testing, to maintain that quality on a bulk order? And will you test the longevity of their cells? On most of the brands, there were disturbing fliers, cells well out of spec, well apart from others, indicating qc problems.

[@keithm39]

Are the generic cells as good to just popping in the modulars without testing

[@johnclarke6647]

The Chinese can make counterfeit Bosch spark plugs that look just like Bosch WSR6F spark plugs, which is why I buy spark plugs from my Stihl dealer for my Stihl chainsaws. I pay a little more for them but I know they are genuine Bosch plugs.

[@pachanoid]

y cual bateria recomiendas aca en chile estoy cachando que son todas fake

[@DownToEngineer]

Thanks for sharing this info! Great content

[@97miguee]

(i am spanish)Which battery did you like the most?

[@miroslavpavlak1319]

Hi, can you post another link for that re-volt 2600mah battery, link in description is broken :/

[@EvolvedApe]

have you set up the import company? if not, I could do it. I have an import company. Normally I deal with larger batteries like 9v and 12v (APC batteries for back ups), but could probably bring this in for you. How many do you think you will need?

[@triplexdread]

Only supply to the states? KZbin is international, right?

[@reidbridges1774]

Great video, like others, have said you got cherry-picked cells. I have received so many fake cells, I cut them open and find tiny little cells inside packed in some powder. I have bought Panasonics that are a rerap knock-off, Samsung that are rerap. Really hard to get quality cells right now with covid.

[@giacomosmiderle9717]

What if there is no data sheet of my battery?

[@corporateair4853]

I thought that storing your cells in a cooler or colder temperature did not affect 18650s any opinions on that?.

[@FieryHyrdra]

Hot or cold will ruin a battery

[@jayank.duggal4814]

what cells are good for a 12V 100A DIY battery pack made of Li-ion cells?? 18650s , 21700s or other. Instead of 10A is it a wise option to good for a 40A discharge with better mAh to reduce the number of cells, therefore less weight. Better discharge so that my motors can draw at least 50A on different motors.

[@surfreadjumpsleep]

pricing on these are so close to lifepo4 cells. Though I'm comparing your 2018 18650 numbers with 2020 lifepo4 costs. lifepo4 lasts way longer so why would you use 18650 for a powerwall?

[@ed-jf3xh]

Didn't the spec sheets recommend never exceeding 60deg C? Just curious.

[@theinnocent714]

Hi i have a question mayb u can help me out. Whats a safe amp draw if i were to connect 3 lithium ion battery in series (11.1volt) the battery specs are: 3400mah rated at 4.9 amps. Its the ncr18650b. Im used to the c rating printed onthe battery not the amps. Thankx

[@jehugarcia]

Those are 3c max I’d say, so 10A-13A

[@christopherdenny595]

This is a good guy......keep it up...

[@karlbartelt3939]

Jehu, when you are averaging 10 cells to need to take out the worst performer and the best performer and average the 8 left, it will give you a more reliable average reading.

[@kenc215]

Im testing a bunch of ICR18650-26F (2600mAh) cells on the LiitoKala Lii500 (NOR test). A lot of them are testing over by 50, 70, and a few by 100 mAh. This is normal?

[@jehugarcia]

Yes

[@MrMAMAO2011]

Dear sir , I need an help to how to test 18650 cell from old laptops batterys using litokalla . I use normally NORTEST with 700 mha charge current. Because I want to garantee the discharge rate is good .

[@jorgezuni2818]

Temperature may be different of barometric elevation or location . That to be considered

[@achilles405]

So I vape and I only use the Samsung 30Q. I found vapebatteries.net has the cheapest cells, American Company, and I've never had an issue with them. Highly recommend you check them out if you're looking for quality 30Qs.

[@colorpanda8409]

What is the Re-volt battery? Where is the re-volt battery manufactured?

[@bobsaturday4273]

hey , your tele has a bix !

[@stclairstclair]

Why is it in every battery video they always have to show off how many they have?

[@salavila1072]

What capacity tester do you use?

[@mataribic3033]

Good hartke bass amplifar, i was had the same.

[@traetuusplays8987]

Yeah you can hit them up for me on that next 4000 battery shipment. Ive got 16 so far.

[@javieruriel]

Where did you get those batteries?

[@lookoutleo]

love your scottish west highland terrior , lovely :) but youve frazzled my nogin, i would like to build a bigger capacity 36v battery for my ebike. its 10a 36v at mo, 10s 4p but its just not enough range. ive been harvesting cells from old laptops but most have very little capacity can you sugest cheap decent cells?

[@mojestravel3702]

How do I get lithium battery cell in Kenya because I look for them at Amazon and eBay I don't find one

[@paulkline7831]

can you link to the tools used in this video? A little annoying that I watched this video to learn how to test batteries and then you don't talk about any of the tools you use.

[@abrahamgalicia5257]

Felicidades buen video amigo tienes nuevo subscriptor aquí 😁

[@polysquare]

In addition to thier discharge performance, how well do these cells hold up to the safety and robustness specs in thier datasheets? For example, the Samsung datasheets claim thier cells will not catch fire or explode when subjected to a 12V/2.6A overcharge for 2.5 hrs, or similar. Obviously, this would destroy the cell's normal characteristics so it's not something we'd like to do with cells destined for a powerwall. But perhaps it would be prudent to also confirm these safety specifications from the datasheet in a real-life test? Especially from a lesser known manufacturer, who may not catch as much legal flak than "brand name" manufacturers if their cells don't live up to thier specs in a spectacular way. It would be interesting to see how all these cells deal with abuse when something does not go quite as planned.

[@jehugarcia]

Totally, I see torture tests in my future for these cells