Whilst preparing for our recent expedition I noted with some dismay that my very first 2,200mAh 3S LiPo, given to me by Gerald, G4OIG early in 2009 and veteran of a few hundred activations, had decided to throw in the towel. It had begun to swell, so despite it still being balanced to within 0.02V at it’s storage voltage of 3.8V per cell I decided it was time to consign it to the great recycling yard in the sky
I connected a 100 ohm 3W resistor across it, and left it out on the patio to slowly fade away whilst I took some of it’s younger siblings up a few Scottish summits On my return, it’s terminal voltage had dropped to around 200mV so I deemed it safe to strip and twist together the load wires, before taking it to the local recycling facility.
If you find yourself in a similar situation, please please DON’T take what seems to be the almost universal advice on the forums and dump your dearly departing in a bucket of salt water, or even worse puncture it/slash it open then dump it in the salt water - at best this wont work too well (the aluminium tabs on the cells quickly corrode away, leaving them impossible to discharge) and at worst the physical damage could lead to violent expulsion of the battery’s innards in your direction, or fire…
Similarly, throwing the battery in the domestic refuse once discharged though often recommended is not a good idea - LiPos do contain transition metal compounds - usually cobalt, nickel or manganese - and it’s better for these not to end up in landfill!
Final observation - the original battery stayed hard and flat throughout it’s working life, whereas the newer replacements all seem to get bloated with gas after a few charge cycles - is it just me or is it a widespread phenomenon?
73 de Paul G4MD