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,

[@Bill23799]

You've gone MAD with power Sir. UP with the struggle of the IR ( Internal Resistance ).

[@khaleef_hrm]

Jehu is now my Favorite 18650/Battery/Power KZbinr. No other comes next.

[@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.

[@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.

[@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.

[@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.”

[@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

[@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.

[@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".

[@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.

[@fernando63014]

subtitles in spanish your work is very interesting thanks from peru

[@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...

[@2061526]

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

[@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.

[@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.

[@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.

[@Q5Grafx]

just ordered a batch of LG mj1s and im hoping theyre the real thing. cant tell from ads.

[@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.

[@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

[@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.

[@XfireKeenmike]

lovin' this vid. Listening and will continue again and again. Love the learning here

[@mikedelcaribe7422]

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

[@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

[@rahmanocawni5618]

Good président you did.

[@shaunblack5365]

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

[@carscoffee5263]

Awesome vid

[@Zener17]

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

[@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.

[@benoittheminerandgamer]

so witch brand is the best?

[@PetreAdrian]

jehu the only thing that is now also popping out is that this Chinese manufacturers are using low end materials for manufacturing the cells that give extremely good results on few iteration but suffer a huge degradation upon more cycles. please do if possible like a 100 cycle for 10 cells and see then the results.

[@MINDLE55EMPIRE]

This really helped

[@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.

[@peterlim7053]

18650 battery for my first encounters with these batteries is during vaping time and my fav is Sony VTC 5 18650

[@pacman4568]

Nice video but all any one needs is to be able to check if they are fake or not by the simplest means possible.

[@baleallout4172]

With the group buy, will you ship to other countries e.g Australia 🇦🇺

[@jehugarcia]

Yes, I think it’s possible

[@washx2k755]

@@jehugarcia if it possible then do it init; if you don't take an action we will lose interest and we will buy from somewhere else

[@CanonFirefly]

Get panasonic PFs from NKON. Better value and good seller out of Europe. Just built an ebike pack with them and they tested great. I'm in Perth so I know how hard it is to get bulk quality cells for a decent price in oz.

[@zevak1]

CanonFirefly I’m in Perth too bro I just started looking for a kick ass setup for my bus

[@adrianjakovac897]

Any advise where/how/who to buy a bulk lot of decent 18650's

[@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.

[@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.

[@juancarloszamorasanchez3613]

Eres un crack Jehu !!!! Saludos ...Thanks,...

[@knalliebar]

About the temperatures. Aren't those at a certain ambient temperature? Probably specced at room temperature of 20 or 21°c. So a few degrees above that could increase temperature especially at higher loads.

[@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.

[@electronica7385]

Eres una maquina!! lastima que no hagas algún vídeo en Español. Es complicado seguirte sin hablar ingles, pero gracias desde España por tu aportación.

[@margeshsanghani4139]

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

[@Broxine]

Awesome tests. thanks

[@kowalskey007]

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

[@NexiTech]

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

[@inekehupkes3228]

what about the lifetime of the cells?

[@bhavinrathod406]

Hey sir I bought icr18650 26j Samsung batteries , I charged them with tp4056 module , initially battery voltage was around 0v and after putting it on charge many hours voltage doesn't rising above 2.5 v ,,, what could be fault plz help me about it sir , the only guy on internet I found is you for this question..

[@traetuusplays8987]

Those be dead cells mate. 0v? You'll never charge them to 3.7v

[@gregorybower2759]

Check out battery mooch

[@DownToEngineer]

Thanks for sharing this info! Great content

[@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

[@caloycoy6133]

Where did you buy those batteries

[@venusreena2532]

So which 18650 is worth buying..for a few flashlites?

[@rohtw2]

10:16 Discharge max 60C degree doesn't mean that the 18650 tube will not heat more than 60C. It recommends to use battery when the temperature is below 60C.

[@racerx1508]

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

[@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

[@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.

[@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?

[@samleonard525]

this is very impressive bro

[@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

[@aaroncatolico7550]

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

[@christopherdenny595]

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

this is a good vid ,i told a friend i liked that company litto kala whatever haha the box was even nice , i love the single 18650 charger for flashlights its great ! i subbed and rang the tacobell

[@shivas1719]

Thank you sir

[@MASKTERTV]

Sir .. hi... Where could i buy those 3200 mah 18650 battery....?? Watching your vid.. from philippines

[@abrahamgalicia5257]

Felicidades buen video amigo tienes nuevo subscriptor aquí 😁

[@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

[@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.

[@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.

[@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 .

[@bobsaturday4273]

hey , your tele has a bix !

[@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

[@dr.t3503]

I just discovered this video. Did you end up getting the OEM battery? Where can I get it? I am very interested. Thanks

[@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

[@motherjoon]

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

[@mataribic3033]

Good hartke bass amplifar, i was had the same.

[@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???

[@aceseightsazhvacsparkyandg8138]

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

[@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.

[@MASKTERTV]

A good quality 18650... 3200mah... Well you give me a link... Thank you

[@kentowakai1234]

Well done hermano.

[@rebelcharlie]

Jehu, how about a project on building single solar panel solar generators, for example, a 300watt panel with a lithuim cell pack , a charge controller and an inverter, all in a self contained unit or two, maybe three smaller panels 100watt panels in a folding configuration, or three 300watt panels that interlock and inter connect as needed? Saludos from PUR.

[@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!

[@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

[@FknNefFy]

☝🏻🤓You sound like that ehhh fururama scientist!! 😆

[@97miguee]

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

[@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?

[@giacomosmiderle9717]

What if there is no data sheet of my battery?

[@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.

[@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?

[@timrollins1015]

I recommend stop caring what other people say. Takes up too much time

[@igorberezin856]

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

[@raulcabe3392]

nice video and tedious work!

[@ginginthing]

Are these scooter pack batteries still available under your listing, best buy on batteries today. Was today 2 years ago?