I take 4 junk 12V batteries and bring them back to life with a combo of epsom salt and used battery acid.
I've now done a part 2 with a cold cranking amp test and opened a battery up so you can see the process. Link below,

   • Reconditioning / Repair an Old 12V Ca...  

#battery #batteryreconditioning #oldbattery #epsomsalt