Small issue with LiFEPO battery


100 W
May 11, 2016
Hey guys, for some reason after sitting for a few months the battery for my wifes bike no longer fits. Is there any recovering this? Maybe try to push it back together with some stick tape?


On a more serious note, what would be the best chemistry for intermittent use, Lifpo, LTO, ...Pb?
When the cells swell up like that, they have usually overcharged or overdischarged or had some other internal failure, and are damaged, and would need to be replaced.

If the battery sat unused for months with the BMS attached, it's possible the power needed to run the BMS drained the pack below usability. (if it was left attached to the bike or any other load, the load could have drained it, even if the device was "off" if it isn't an off switch that actually physically disconnects the battery from the load).

As for what to replace it with...if it only sees a little use every so often, get or make a pack that you can completely physically disconnect the BMS from, or ensure you test the battery and recharge at least partially as often as necessary while not in use.

There are various storage protocols discussed in many threads around the forum, most of which recommend leaving the battery at 50% or less amount of charge, to lower the stress on the cells (increase lifespan). But if you have a BMS or other load on the battery, the drain from it may kill the battery in the time it sits there if you don't monitor it.

Lead would be the worst choice, as it will self-discharge even if not connected to anything. (well, everything self-discharges but lead is pretty bad about it). Also, lead will be damaged (sulfated) by not being at it's full-charge state.
That battery is toast. I would figure out how to dispose of it properly and get it out of the garage ASAP. As Amberwolf suggests there are proper ways to store a battery that will prevent this, better luck next time!
It was maybe 10 yo, old probably lived a better life than most. Until I can get the time to desolder the cells, its sitting on a concrete slab, more than 3m clear of anything, inside a 1.5mm checker plate steel box (with the lid shut but not latched, I know about confinement), surrounded by bricks. I may have been a little concerned about it catching fire...