Vintage465 wrote:
I have two 6v interstate batteries, purchased new in August 2015. I did flatten them twice and by flatten I mean zero volts. I have been provided with tons of info on how not to flatten my batteries and how to see if they are still good. I got them up to a full charge disconnected the ground, let it sit 24hrs then checked them with a hydrometer. All the cells were way up into the green and very equal.
Never say never but considering a totally "dead" 12 volt battery's unloaded voltage will read no lower than 10.5 volts (half that for 6 volt batteries) it's hard to believe that
any battery truly reading "zero volts" could possibly ever be recovered. Sounds like black magic to me. :W