Mechanic says battery has low voltage

part 2 of the story. I bought a battery at Sears last year. last week when i was having the oil changed, the mechanic said my battery showed "low voltage". i went back to sears. they said their machine showed my battery had "low voltage"; said i needed a new starter and they referred me to another mechanic. he tested the battery on a different type of machine, said the voltage was fine, and i didn't need a new starter.

i have intermittent problems starting the car. basically the engine will not "turn over" without it having to chug a bit.

any suggestions on what to do? do i just wait for the battery to die?

thanks in advance.

Its not too hard to measure the voltage at the battery terminals. It should read about 12.6 volts with the engine shut off, and at least 13.75 volts with the engine running at an idle.
The symptoms of the engine turning over slowly at first, then turning faster is a common indicator of a starter whose brushes are worn down and the commutator is covered in grease. As the grease gets heated by the electrical current it thins out and the starter turns a little faster.
But it could also be a bad battery cable or connector. Both the positive cable and negative cables could be bad - usually from corrosion. The corrosion can be hidden under the insulation too. To get a good look at both cables and check them out for being healthy I imagine you would need to remove the battery, & the big air inlet duct. The positive cable runs behind the engine to the large screw post on the starter - which contact can also be bad. This you would have to inspect by looking up from below. Installing all new battery cables might be a good idea too. At least it would eliminate the cables as the problem.
Replacing the starter is also done from below, and reaching the uppper bolt, (one of two that holds the starter to the engine) will require about a 9" extension on the socket. I forget if the socket is a 12mm or 13mm or a 14mm.