18650 chargers

[Wayne's World]

Looking for used chargers with capacity test. Brisbane (Australia) Northside. LiitoKala, Opus, pack charger etc.

 

[Crimp Daddy]

Just a thought, but if you want the LiitoKala you should consider keeping an eye out at AliExpress... if you buy without the power adapters, and make you own power distribution which you will most likely need to do if you have a few, the you can get them pretty cheap.

I paid $13 each after waiting for some coupons / volume discounts.

Here is an example...
https://www.aliexpress.com/item/400...earchweb0_0,searchweb201602_,searchweb201603_

 

[Wayne's World]

I just bought another 500 and a 500s on Aliexress from the LiitoKala store with the 50% off sale. I should have bought a couple more 500. Planning on getting an Opus from Lanplus in Australia.

And yes, the plan is to use an old high current power supply and make a 12v rail, and rig up a cooling bench for them all.

 

[Crimp Daddy]

If you are going to use the 500, keep using the 500. Do not mix and match testers, it will skew your results and create problems with the final product.

The most important thing in capacity testing is consistency in the testing process. If you use different testers, you loose that as they don't all meter the same.

At the end of the day, the actual capacity number is irreverent, what is important is that number in relation to the next cell. I could have a tester that tests 50% higher than the actual capacity, which is totally fine as long as I use the same tester for everything, I will end up with a more balanced pack than if I was to mix and match testers.

 

[Wayne's World]

Agreed. I wanted the 500s specifically for the 0v recovery, and the OPUS just because I hear its a good charger and I want to see what it can do and how it compares. I've just ordered another 3 Lii-500, and looking to make a charging/cooling rack. I might use an old PC PSU. Not that its needed in this weather cool Brisbane atm, but for safety and convenience.

 

[Crimp Daddy]

Personally I think the 500s are terrible for 0v recovery.

I would use a parallel cradle and a CC/CV power supply and bump them up at 10-20mA until you get to about 3v.

A bench / lab power-supply works soo well for this (that is what I use) , but if you are on a budget, I highly recommend this little thingy. I have one too and it works well.

https://www.aliexpress.com/item/32872607362.html?spm=a2g0s.9042311.0.0.78804c4dVmKkcE

 

[Wayne's World]

Cool gadget. Might get a couple. I've had a benchtop PSU on the list for a while, but hasn't been a necessity. It'll be useful for upcoming projects though, so I might do some research.

I've had success recovering 0v cells by paralleling with a good cell, and with a cheapo DIY USB powerbank, till I shorted that and killed it the other day.

I need to setup something more efficient though. About 1/4 of the cells I'm getting are 0v. Its usually an entire pack, and occasionally a pair in a pack. So I'd like to try and recover them. Many of them are 25R's. Would it work putting a bunch of similar (low) voltage cells in parallel to this DC DC unit you linked, and multiplying the current?

 

[Crimp Daddy]

You are literally doing the worst possible thing you can do to a 0v cell... you are bumping it back up with too much current. You can't control the charge current in parallel and the initial inrush is probably much higher than you want it to be. Doing that can cause permanent damage and will increase the likelihood of an internal short because that is how you create denrites between the annode and cathode. It just keeps growing until it breaches the separator and shorts out internally.

You must use a controlled LOW constant current charge rate in the 10mA to 50mA range to try and recover them.

I'll be 100% honest, I don't use 0v cells in my builds. I have recovered plenty, but they are generally in worse condition than you think. The permanent damage wont be realized immediately. I consider them to be "ticking time-bombs"

I would just bin them and move on. I know it sucks, but just know what you are getting into.

 

[Wayne's World]

I understand the basics. I literally connect them for 10-15 seconds to get the voltage high enough to be recognised by the charger. I did use the USB powerbank as I mentioned, but I won't do that again. I've marked them all, so intend using therm for test packs or the like.

 

[Crimp Daddy]

I have done this as well, but ultimately decided it wasn't ideal just throwing both in parallel.

That said, it can be improved on for very little money. I have single cell holders and put them in parallel with a resistor between the two. There is also enough room for a current clamp to monitor. This help keep the current down significantly.

Just a though.