18650 Battery Capacity Tester from eBay

A simple battery capacity tester from eBay, perfect for 18650 batteries and USB powerbanks.
The tester includes two ceramic resistors (7 Ohm 5W). Using 1 of the resistors against an 18650 is equivilent to 500mA and using 2 resisotrs
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[@MCsCreations]

Really nice! A question: if I solder the resistors with a thick wire, so I can use a heatsink in them, the soldering would resist?

[@throttlenerd]

Super, thanks man! Could you please help me to understand how to recalculate the mAh values if I’m testing the powerbank with constant ~5V output? Or I just multiply 5 and amp result, then divide it by 3.7 and thus get an approximate mAhs?

[@MrHassancehef]

cool video! what would be the lovest resistors you would use on it? what is the lowest cut off voltage you can set ? (If it's low, it could be porbably use for testing nimh also)

[@publicmail2]

True, most all large batteries are tested over an 8 hr period for Ah. As you mentioned you get more pulling less current over a longer period of time, that applies to Ah rating only.

[@sammy-pp1gl]

Hi , Very good info ,I have salvaged some 18650 batries from my old lap top. Only one has the full 3.7v and the rest is totally dead . I used my volt meter and checked the voltage and found no current at all ,I managed to revive those dead cell which now has some voltage in it as 1.2v .so i used my charger to charge it ,but the battery charger power trip and not charging the cell at all . Can i use this capacity charger and discharger to power the battery ,,and if can how to do it and how many resister to use .. your kind advice please .

[@familybrown2283]

I ordered two of these. I was a bit peeved when what arrived was not the ZB2L3 but the other commonly available one, the HW 586. When I queried this the seller said "they are the same". But the HW 586 has a critical appraisal here on u-tube. Anyway I checked them out and the performance and operation does seem to be essentially the same. Results were exactly in the expected ballpark, when I swapped cells over to test consistency with the other board any discrepancy was typically 1-2%, never more than

[@pleasecho2]

Assuming the tester will run at lower voltage and not draw too much itself, why not use the 18650 to power it?

[@AdamWelchUK]

These types of capacity checkers are really useful. I built one myself using an arduino and the parts probably cost as much as this item. Your two 7.5ohm resisters in parallel give a nice 3.75 ohm load which is almost perfect for a nominal 3.7 volt battery and an average of 1amp load. A resistive load gives a good example of how long some types of devices would run for on a specific battery, and a constant current load gives a good idea for other types. So they are both useful to have. Thanks for the video.

[@GadgetAddict]

Good info and yeah I'm happy with my purchase :) It's nice having a standalone tester for when I cant leave my laptop running the EBD-USB tester.

[@ANDYMCNET]

For anyone that doesn't know Adam Welch has a total amazing channel himself and his knowledge is legendary. 👌 I've never used an Arduino in a circuit before but I think I might try building this one. Iv already built myself an amazing DC to DC Buck Boost charger for my motorcycle thanks to Adams advice. Probably my favourite channel along with AVE & Big Clive. 👍 P.S. Thank you for this review as well its also a good video. ❤️

[@MichaelAirbnbHost]

I see, so the omh's gets cut in half when you double the resisters? what about the watts, is it 10 watt now or does it stay 5 watts? And can you lower the ohms too much for these cells?

[@PrajwithUllal]

Can u send me the link of eBay or Name of the product

[@james10739]

I have one of those and man that connector is brilliant because I was doing 18650s and also I started doing AA batteries also and it is kinda annoying changing the holders out basically any alkaline battery is pretty good even the cheap ones but the non alkaline batteries are like 1/3 of the power

[@thiamjoo]

Is the cut off voltage of 3V standard for all Li-on capacity tester? What if you set the cut off to 2.7V, wouldn't that give the battery a higher capacity reading?

[@aspergerhellasbn]

You would help alot if you can answer me .I build a 3s-4p battery pack out of lg 18650 cells. I tried to measure the capacity.I firstly charged and then discharged the pack.Turnigy smart charger has cut off voltage at 9,6 when having a 3s battery. When the discharge finished i show total 8000mah and voltages 3,4-3,2-3,4. It did not stopped at 9,6 and my main problem is that my second series batteries discharged faster. So having a pcb when u use the battery will cut the output voltage, while there is still voltage left in the pack .how to fix this? P.m all are same new lg cells except 1

[@JoseGarcia-px9xj]

so you know the capacity, witch ones you connect in parallel

[@Coffieman5150]

Is there a data sheet for this tester? If so please post it's link, thx.

[@Darkryoka]

i don't understand.. so what the number of capacity that batteries?

[@brannenthompson9662]

I finally got mine the other day and set the cut off for 3.2 volts but after checking and removing the 18650 it shows 3.4 volts and also when inserting a fresh fully charged 18650 4.2v it shows a starting voltage of around 3.8 when starting to draw current am I doing something wrong? Thanks, great battery as the tester comes with no instructions.

[@muhammetolmez530]

its normal for voltage to drop under load

[@Ziplock9000]

After capacity testing, should you leave them at the 3v? or charge them back up to nominal 3.7 for storage?

[@emilehoffmann]

John Michael Stock It’s better to get them up to the storage voltage.

[@barbadolid5170]

Safe cutoff voltages are between 2.4V and 2.5V, cutting it at 3 won't show the actual capacity on the meter's reading.

[@hungnguyen-vq7kd]

Yes,, but it is depending on manufacturer, battery he is using not a brand name, if he set cutoff voltage down to 2.5V battery may over heat.

[@NoFear4XJs]

Is there a circuit board that can be connected between a battery and a device that will state how long you can operate before it reaches a set cut off point ? Maybe a timer that has taken into account the volts and amp draw automatically.... This would be a money maker, even if the circuit board had to do a one time drain on the battery it could have a memory that could be reset... Their must be many ways one can be designed and set up to function. Thank you for your time.

[@GadgetAddict]

If you search for 'lipo battery alarm' on eBay, you'll find many devices like you described and usually they have an adjustable voltage warning and can be used with many battery types.

[@NoFear4XJs]

Awesome thanks !

[@stevehodges6792]

hi any chance you could explain how i would calculate the capacity as i would like to use this tester to test capacity of a couple of usb 5v power banks i own. thanks

[@hungnguyen-vq7kd]

search and buy a "USB Power Tester Voltage Current Capacity Meter". So you don't have to build a cable this tester had a usb input so you just plug in your power bank and other side it had USB output to plugin a lamp or something using power to test a capacity of your power bank.

[@asiluzunlar2596]

I bought same capacity tester but indicator display wrong voltage. That's why it measures wrong capacity. How can I fix it? Edited: I fixed it. Google it "zb2l3 calibration"

[@zamazakati]

Did you calibrate the device?

[@gordiebrooks]

Couldn’t you just discharge the battery for say 30 seconds to workout the estimated mAh without draining the entire battery? Most smart charger meters/analysers these days tell you exactly how many mAh the battery was charged for.

[@alfblack2]

I want one of those too! Sweet.

[@bebangali6617]

I bought two of those did you use both resistor most video I Saw used only one will it be fine does it make a difference

[@trif55]

I bought one and it came with 2 resistors, it depends if you want to measure the capacity at 1AH or 0.5AH, this mainly depends on your usage

[@BasementBen]

Blows my mind this is like $1 from China. Would have made hobbies immensely helpful years ago!

[@saleemkader2126]

I have tested the same 18650 battery twice first charging them to 4.2v with two of the load resisters and set 3 v cut off voltage and there is a huge difference in capacity on all 12 of my capacity meters.

[@muhamed-ramadan]

my zb2l3 is the same, no accuracy at all, did u find any solution ?

[@2kMario]

Is accurate method ?

[@ackenta]

Hello. Can you explain why do you use the two resistors instead of only one to make the test? Thanks and btw, nice video

[@GadgetAddict]

If I only used one resistor, the load would be closer to 500mA instead of 1A. Since most powerbanks, cellphones and other gadgets charge at 1A, I find it's a better test value.

[@ackenta]

Thanks. I asked because I can't take more than 160mA from any 18650 battery, using the two resistors, while with one, I can get only 100mA.. Any solution with what can be happening? Thank you

[@GadgetAddict]

That's odd. How did you connect your 18650 to the tester?

[@ackenta]

Gadget Addict, I use those plastic holders for 18650 li ion batterys that you can find easily on ebay.. I tried to discharge with only one resistor, and I get only 100mA,and 159mA with the two resistors.. I even tried to change the conectors from the holder cause they seem to be too fragile.. I don t understand what am I doing wrong :c any advice? Thanks by your time

[@dungcukhongday5697]

Ackenta increasing discharging current

[@dimosvamvourellis]

I have an other problem where I charge the battery to 4,2v but when I but it in the tester it shows 3,4v and this happens with two completely different testers. What you think the problem is because if I put 3v cut off the mah reading won’t be correct.

[@hungnguyen-vq7kd]

Maybe your battery is weak, Normal Lithium battery voltage is 3.6V or 3.7V it may slightly higher depending manufacturer and battery Specifications. 3V cut off mean when you are using your battery then battery voltage will going down, so when battery voltage get down to 3V it will stop (cut off power) you from using it. Like a power tools when this happen a light will flashing and no power out put from a battery.

[@rosekreuze]

i have the same batteries that has higher resistsnce. one claimed to 1600+ mah but when i discharge test it using only one reeistor, the voltage drop tremendously. if it cant handle half an amp, what more if i use two resistors, lol! so technically, we have both tested a bad bwttery

[@AcidRainSleeves]

LOVE this video mate. I was wondering though if I were to buy a new resistor, what would this thing be able to handle? I only gor one with mine and it says "5W 75ohm J" and I don't really know what that means :S

[@aksquad5522]

7.5 Ohm

[@hungnguyen-vq7kd]

With his circuit board Max current draw can handle is 3A, so you can use 10W 1.5 Ohm or 2 5W 3 Ohm resistors in parallel.

[@danhle1032]

what's the difference in putting the resistors in series vs parallel?

[@hungnguyen-vq7kd]

He is using 2 5W 7 Ohm resistors in parallel which is 10W 3.5 Ohm, Current = Voltage X Resistor so battery he is using 4V X 3.5 Ohm = 1.14 A ( current draw ). For this circuit you can use a Resistor 10W 1.5 Ohm for a current draw of 2.6 A ( Maximum current draw for this circuit is 3 A ).

[@TheRealThisIsAlex]

It's very neat!

[@jarednormanyanosbusandtruc321]

that is recommended for make a Piso Net Machines

[@jhizzh2]

why not test the blue/orange battery that came with the power bank it self

[@GadgetAddict]

I don't have the original battery anymore. I cannibalized those cheap cdrking powerbanks to act as standalone battery holders like you saw in this video or as basic 18650 chargers that I cycle different batteries through.

[@IvanRiveraStagea]

With so many counterfeit 18650 cells around, where do you source legit ones? Thank you very much!

[@GadgetAddict]

Well that's a very good question. Even Amazon gets flooded with fake cells or sellers that start with genuine cells and then swap for clones/fakes. I generally try to buy from somewhere that has a good returns policy (like Amazon) and then test them on arrival. If they don't hit the specs or there's something that shows them to be fake, I send them back for a refund.

[@neutronpcxt372]

Power banks for high capacity low load cells. They can be as low as 2.5$/cell, which is very good.

[@NicholasMontesa]

Pretty helpful

[@rviejohn]

can you make a test of Golisi 26650 4300 mah? :)

[@hungnguyen-vq7kd]

you can use a same circuit he is using.

[@trif55]

I have multiples of these, is it possible to solder a 5v power input somewhere directly to the board instead of using the USB? Nevermind, I noticed the two square unused pads on the back of the PCB near the USB end, +is right below the USB port, negative is offset behind the AH A V lights

[@publicmail2]

How did it compare to the EBD with Ah?

[@GadgetAddict]

A difference of around 150 mAh. But when testing with the EBD-USB I had a constant 1A load while this load varied from 1A down to 0.8A as the battery voltage decreased. So I'd say they're both pretty close to each other.

[@tonbovee5486]

ericcl

[@5041042]

There is difference btw the results of this capacity checker and litokala Lii500, why?

[@jopalzm1]

Yea, i have this problem too

[@solopomodoro5853]

@@jopalzm1 how big difference?

[@jopalzm1]

@@solopomodoro5853 3x Liitokala paralel HG2 18650 3000mAh show mi tester 6800 mAh, repeatedly.

[@solopomodoro5853]

@@jopalzm1 did you try what capasity each cell alone showed? Meybe they arent full 3000mA?

[@jopalzm1]

I understand, but it is connected as the power bank and the problem is unraveling it. But I have the similar experience when bought a 20,000 mAh from a branded power bank manufacturer and the test showed 12,000. Complaint powerbank, I get next kind, and showed 11,800 mAh. So I don't get it.

[@gsmgsa]

Well well well... what about the connector's losses? :)

[@GadgetAddict]

There's only so much you can do. I've tested this battery in 4 different ways and all tests gave very similar results which suggests the wires and connectors used aren't that important if they're kept short. It might not be good enough for a space rocket but it's close enough for a normal consumer.

[@zz2nkt]

Have resistence measure?

[@exgenica]

Many of these kits seem to come with a pair of 7.5 ohm, 5 Watt ceramic resistors. The resistance tolerance may or may not be marked. Assume +/- 10% if not marked. Two that I received measured 7.44 and 7.50 ohms. They may also be marked something like this: 5W7R5, which in this case meant 5W 7.5 ohms. It's usually a good idea to confirm the at least approximate values of parts like this by measurement especially when the price of something is really low. For example, a manufacturing or packaging mistake could send you a 0.75 ohm resistor instead of a 7.5 ohm resistor which could drastically change your results and any calculations. Also, while ceramic resistors can withstand high temperatures, be prepared to keep them cool with a fan as they could cause burns or melt plastic parts, insulation, etc.

[@prads34]

How long does it take to discharge 1 18650 cell on this ?

[@GadgetAddict]

It would depend on the capacity of the 18650 cell.

[@prads34]

Gadget Addict I was looking for a rough estimate.iv ordered similar one from aliexpress but have to wait another 40days for the delivery.btw nice work on the turning old battery bank into a holder👍

[@GadgetAddict]

Anywhere from 10 minutes to about 3 hours. Depending on the capacity of the cell :) 40 days is a longggg time to wait!

[@matejhlaca5171]

If you have battery with capacity 3000mAh this is 3Ah and you are discharging with 1A it will take 3hours

[@br1ckbr3ak3r]

The device is capable of 3A discharge. If you were testing high draw cells and wanted a 3A discharge you would have to get appropriate resistors to load it?

[@deriklfixit]

I realize its easy to make but i still would rather just buy yours. You should pre-make a few and trow them on ebay.. I want to buy one just like you have but i don't care to collect the parts and make it myself.

[@SJChip]

With all the 18650 batteries in use now, I just don't get why NO ONE has simply put together the already - available components into a single box with a proper 18650 battery holder, freeze the settings to 18650 batteries and print the instructions on the box. I'd gladly pay $10 for that, and I'd pay $20 for one that I could put 4 batteries at the same time into (discharging takes hours). It would sure beat breaking out all this stuff.

[@cbm80amiga]

Can you provide the link to ebay item?

[@GadgetAddict]

It wouldn't be practical because eBay sellers and listings come and go all the time. If you search 'battery capacity tester' on eBay you'll them listed by various sellers :)

[@cbm80amiga]

Ok I found such testers at Aliexpress for $3.25 cheapest. However I have IMAX B6 mini battery charger so I will rather wait for something smarter where I will be able to choose constant current more convenient way than using external resistors. Thank you for your finding.

[@GadgetAddict]

You might want to check out the EBD-USB that I previously reviewed - kzbin.info/www/bejne/oGPMkquHgNiqf9k

[@IonMan]

yeah cdr king🔋

[@Linkachus17]

Hey thank to the video now i can test fake battery capacity now

[@joshuahuang07]

omg u're supposed to use both resistors at a time lmao. No wonder my resistor was burning hot

[@GadgetAddict]

They'll get hot either way :)

[@joshuahuang07]

Gadget Addict haha yea i just tried it and it got too hot to touch within 1 minute. Does yours get this hot too? I'm scared to leave it on for over 5 mins

[@didtoknan8128]

They can only dissipate 5W. 10W resistor would have been better.

[@SachinUK08wala]

Send me links module chager