‘Free’ Power Bank

‘Waste not, want not’ was another of my mother’s favourite maxims – one I have certainly taken to heart, as my wife will attest as I have fill our house and sheds up with all sorts of ‘mathoms’ – hobbit for ‘junk’.

I had two ‘dead’ laptop batteries which I probably ought to have binned or recycled but today (it was raining) I decided to dismantle them instead and stripped off the welded tabs. Each contained 6 x 18650 rechargeable lithium batteries.

Each cell was dead flat. After placing them in the single power bank I recommended here they (surprisingly) all came back ‘to life’.

Lightest Power bank

Once they were charged up a bit I could put them in one of these four cell power banks where they came back to 100% – as you can see.

Free Power Bank

Each cell seems to be (about) a 2200mAh Samsung 18650 battery, so I have now got three 8800 mAh power banks for just the price of the cases ($6 in total). I have used one to charge three phones from flat then recharged it to 100% again, so they are going to work.

I used a pair of long nose snips to dismantle them, then a pair of pliers. Here is the process in pictures:

Free Power Bank

Free Power Bank

Free Power Bank

Free Power Bank

Free Power Bank

The empty power banks cost US1-2 each, so this is a big saving. Dead Teslas would have probably 1,000 or more of these things in them, but I’m sure you can find a dead rechargeable drill or robot vacuum cleaner battery etc lying around which has quite a few too, and maybe of better quality than these ones.

Lightest Cheapest Power Banks


2 thoughts on “‘Free’ Power Bank”

  1. Hi Steve, Very interesting. Do you have any ideas on why the single batteries ‘came back to life’ when they would not charge in the original power bank? Was the power bank’s charging circuit defective? Timtinker

    1. One of them had been brand new. I suspect that when a group of cells falls below a critical voltage that they just can’t start charging collectively yet they can still start charging individually. I’m sure there is a scientific explanation for this, but one set was quite old yet they are holding now seemingly perfectly too. All I can recommend is that we stop throwing them away. Cheers, Steve.

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