When do you replace a battery?

[Johnp33]

First off a lead acid battery has 12.6 volts in it that is all it may have surface voltage above that but not for long.
To charge a battery fully it needs at least 13.8 volts to get a full charge.
On rebuilding batterys I think every town use to have someone that did that at one time, I was one of their customers, if it failed the guy would usually just give you anouther one for free.

 

[ultrarunner]

Never used a Battery Minder... have another brand with similar claims.

So far I have no complaints.