We must remember volts is NOT amps! It takes more amps to run the starter than anything else.
The test is simple turn on the headlites and then when they are on hit the starter If they dim greatly the battery or the cables are bad.
If the cables are growing a beard after cleaning them the chances are the battery is going soon..
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

professional bovine relocation specialist