In Reply to: Re: The Old Girl Wouldn't Start. posted by 49er swGA on March 17, 2019 at 13:33:15:
As a battery ages, lead sheds off of the plates and collects in the bottom of the battery. This eventually causes a short between plates and you have a bad cell. By bumping the battery you dislodged some of this soft lead deposit.
What Dan is suggesting removes that lead deposit. However the capacity of the battery will likely be diminished due to the loss of plate surface.
I've never attempted to do this.
Be careful! Sulfuric Acid is dangerous.