Learned something from my dad today. One can measure each cell in a lead acid battery and see the voltage raise between cells due to them being in series. 6 cells at approx 2v each should give 12v. But today we found out that this 7 year old battery has two cells with little to no charge.
Also goes without saying: corrosive acid bad. Use caution and safety first.
Also got to use coke for corrosion for first time. .. how do we drink this stuff without dying?