General Category > Batteries & Solar

18650 battery testing

(1/3) > >>

Andywragg:
So off the back of my 18650 bulk purchase, i thought I'd better get some means of testing them.

First of all I ordered one of these;

https://www.ebay.co.uk/itm/Battery-Capacity-Meter-Discharge-Tester-18650-Li-ion-Lithium-Load-Resistors-UK/122484972541?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649


It came the other day, and I havent had chance to use it yet, but I kind f had a WTF moment when I thought about how long it would take me to process 40 cells using this device.

I also thought about how to charge them to enable the tests. I do have a number of the individual cell chargers that you get with the cheap ebay flash lights. I also have on of of the Xtar smart 2 cell chargers but that has developed a problem where only one cell charges.

I looked a couple of videos from guys that are processing a good number of cells and they are using the Opus BT-C3100 charger and tester.  So I've got a pair of them (the V2.2 version) on order from GearBest. This will allow me to test 8 cells concurrently, and also allow me to charge other cell types and chemistrys (secret switch inside alters the max charge voltage).

https://www.gearbest.com/chargers/pp_174044.html?wid=1433363

Obviously at some point i need to consider the solar aspect but this will do for the QTH. Once the chargers arrive I'll get busy testing the cells out and keep you posted.

caulktel:
Hi Andy,

I had to do the same thing when I started working with 18650 batteries but I bought this  tester.

 https://www.ebay.co.uk/itm/1pcs-Constant-Current-Electronic-Load-9-99A-60W-30V-Battery-Discharge-Capacity-C/191883750242?epid=2024203215&hash=item2cad29ab62:g:mp4AAOSwintXSj2m

Works great.

Joel
N6ALT

Andywragg:
Yeah I saw that product as well.

The Opus chargers arrived on Friday, but I've been away at a bushcraft meet over the weekend so didn't get chance to have a look at them.

I put the first 8 cells on the chargers yesterday. Some cells were below 3v but above 2v and the chargers still charged them to 4.2v irrespective. They are current undergoing a 3 cycle test since yesterday. I'm using the default 500ma charge and discharge rates, so a complete test takes around 27 hours.

The cells are 2800mah nominal based on the markings on the cases and the sleeve/ring colours. I'm already seeing capacity of over 2100mah for most cells.

Andywragg:
The first batch of 8 cells completed Yesterday, or maybe the day before - this week has been a blur as my wife had a heart attack Tuesday evening, so I've been shuttling to/from the hospital since.

All cells are usable and are giving me between 2100 and 2300mAH,  all with internal resistance below 150.

I have another batch of 8 on test now. I'll test all 40 cells then group them based on capacity and internal resistance. My BMS boards have yet to arrive, the slow boat from China must be taking the long way around.

caulktel:
Sorry to hear about your Wife, I hope she will be okay. Good new on your cells. i need to test the bunch i have and build some new packs.

Joel
N6ALT

Navigation

[0] Message Index

[#] Next page

Go to full version