Hello from Melbourne, VIC

[finisterre]

Hi all,

My name is Darren. My job involves sometimes repairing a certain brand of household cleaning equipment that essentially gets a battery module replaced. The old unit is usually thrown into e-waste bins, but I have been collecting and extracting the (Samsung) cells from these modules (what is left, charging circuits, holders etc. are put back to recycling) and have now got a reasonable quantity (est. 150-175 cells?)
Charged most of these with a Yonii charger from Amazon, but some of course don't make the grade. That is why I was looking for resources on how to test and possibly revive those cells if possible)
I hope to learn a lot here.
Thanks!

 

[OffGridInTheCity]

Welcome to the forum! Over 100 cells... if you turn away now there might be hope you'll escape the addiction that has overtaken a lot of us

Hi all,

My name is Darren. My job involves sometimes repairing a certain brand of household cleaning equipment that essentially gets a battery module replaced. The old unit is usually thrown into e-waste bins, but I have been collecting and extracting the (Samsung) cells from these modules (what is left, charging circuits, holders etc. are put back to recycling) and have now got a reasonable quantity (est. 150-175 cells?)

I see a YONII charger on Amazon - powered by USB it looks like. Would suggest a beefier charger such as an OPUS (https://www.amazon.com/Opus-BT-Intelligent-Compatible-Batteries/dp/B01852TBOU) or a Zanflare (https://www.amazon.com/gp/product/B07428G1G2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1) or something like that that can charge/discharge at 1000mah per cell x 4.

Charged most of these with a Yonii charger from Amazon, but some of course don't make the grade. That is why I was looking for resources on how to test and possibly revive those cells if possible)
I hope to learn a lot here.
Thanks!

There's often discussion on 18650 cell test steps such as this thread with a flow chart later on in the thread - https://secondlifestorage.com/index...to-test-my-cells-18650.9560/page-3#post-66447 - and the sites FAQs.

Sounds like you have 0v cells? For the most part these are difficult to recover. A think a general consensus has formed over time that cells should have 'something' left - 1.5v or 2v or even 1v etc - before making it worthwhile to recover. In my own experience, recovering 0v cells has been a very low % success.

 

[italianuser]

Welcome Darrento revive cells you could try feeding them with a real low amperage at 3V. When (if!) they reach 3V you can try to charge them to the next step 3.5V. To do this I use a 2$ variabile DC-DC step down converter bought on AliExpress. After 3.5V let them rest to see if they die again, if not you can try them in the real charger

 

[floydR]

Welcome to the best DIY lithium battery site on the net. As OGITC says it might not be too late to turn away. What italianuser says is good advice. low amperage is 100 or 200ma. even less if you charger can go lower.
Later floyd

 

[Redpacket]

Using an IR tester like a YR1035 would be a good idea. Bad cells typically have higher IR.
Have a look at these cell testing flow charts to help weed out bad cells:

18650 Harvesting Flow Charts

As a community we all have our different ways of processing cells and I wanted to take the opportunity by starting this thread to find some common ground on how we all should harvest cells. This is not meant to be a "be all end all" but more of a guide for new members and maybe some senior...

secondlifestorage.com

If cells are bad, "reviving" them isn't such a good idea. Cells with initial low voltage can develop sudden internal shorts later & be a fire risk.
If they are self discharging you might get some secondary use, eg in torches, etc.