I have recently accidentally come into possession of a bunch of old lead acid batteries, ranging from a few months to several years without charging or maintenance. I could just get rid of them, but I would like to recondition and reuse them as additional power storage for my solar array, if possible. I have been looking at desulfator chargers online and I am planning on getting one and hooking it up to the batteries and just seeing what happens.
Does anyone have any experience reconditioning old lead acid batteries? Are there pitfalls I should be aware of? Since they are of unknown condition, am I better off scrapping them and buying new?


Some tips: listen for bubbling. If a lead acid battery makes bubbling sound, that means it produces and vents hydrogen. That’s not supposed to happen outside a short period at the very end of charging (equalization period).
If it happens early, there could be one or several dead cells, causing other cells to experience overcharging. If it doesn’t hold a voltage of at least 2V per cell (6 cells = 12 volts), discontinue using, as a dead cell is then very likely present in the battery.
good note, I’ll keep a lookout for that.