How to test/charge laptop/cellphone packs directly.

Found these two videos by EcProjects, might help people find which batteries have the most life left before ripping them open.

Great find !

If you have a batch of Lenovo batteries (Perhaps from abusiness), Lenovo sell an external charger which works for almost all thinkpad batteries(https://support.lenovo.com/au/en/documents/migr-61244).I have not looked into it but other manufacturers SMBus batteries may be compatible (no idea)there are also generic external chargers on ebay. This could be an option to pre-test packs onsite before you purchasewithout going to the effort of opening them.

Ever open a laptop pack and have the banks at vastly different voltages, even though there is nothing wrong with the cells?
I think that just as often as bad cells we just have a bad controller board in the laptop packs, and that is how it gets thrown into the scrap bin. I test the individual banks when I disassemble each one, and I have 2 separate boxes that I throw the controllers into. One for OK boards and ones suspected bad, or damaged in opening. I find I can reuse many of the components off these boards, like micro-switches, diodes, etc. But the known good boards can also be reused for rebuilding small dedicated packs.

But since you don't know if the board is good before you are able to measure individual charges, I wouldn't try to recharge directly. Instead. I leave the cells connected intact and quickly balance them then bring the whole pack to 3.9-4.1v per cell using a DC-DC converter with constant current, before disassembling the individual cells for final finishing charge and capacity test. This greatly cuts down on the amount of time needed to charge the individual cells. And if I cant capacity check them right away I make sure they are all between 3.6 - 3.85v for a safe storage charge.