"We don't use voltage; 12.57 volts or anything else to measure if a
battery has remaining capacity. In fact voltage is a very poor way to
determine the capacity of a battery. Especially lead/acid 'storage'
batteries; although voltage may be of some use with the cheap small
disposable 'primary' batteries (AA, C, D etc.) used for flashlights etc.
There are some voltage numbers that MIGHT be of some use after a
disconnected battery has been left standing for 24 hours without
charging or use. But to test voltage of the battery in a car that has
just been driven (to the oil change location) a short while before
probably meaningless.
We recently had to change the battery in a friend's Toyota that was 13
years old. Before and after changing the battery we tested the charging
voltage which was and should be in the range of 13.8 to 14 volts (or
little higher with some modern cars) AFTER STARTING AND WHILE THE ENGINE
IS RUNNING.
The 8+ year old battery in my Nissan pickup is working fine, starts
every time, in this cold climate. In fact 'hot' climates often worse on
batteries.
And even if the battery HAD only 388 ampere hours capacity remaining of
the original rating of 600, that's still 65% and if that is starting the
car correctly no neeed IMO to change it! The battery will probably
finally die after some 10 to 12 years; unless vehicle is being used as a
taxi or delivery vehicle that requires frequent starting many times
during each day."


WOW back to the subject! I think everone agrees it's a scam.

Thanks