It's tough to say just from that whether your battery is good or bad,
but at least the voltage appears to be OK.
For a slightly better test, turn on the headlights for about 10 seconds,
turn them off and check the voltage again. If it's still 12.6 or above,
your battery is at least charged.
However, this still won't detect many common failure modes, including
just being "worn out", eg not enough material left on the plates; or
having a high resistance internal short ("won't hold a charge").
Sears used to offer free battery and charging system testing, don't know
if they still do that. Some auto parts stores will do just the battery.
For a more functional test, I'd suggest disconnecting the battery from
the car (after slow charging it), and letting it sit overnight. (If
your car has electronics that need to stay powered, connect your slow
charger to the cables before disconnecting them from the battery.) If
the battery won't start the car in the morning, the battery is bad.
Certainly, finding only one cell dry is usually an indication of a bad
battery. That cell was weak to begin with, causing the electrolyte to
boil away. As the electrolyte level drops, the current gets
concentrated across the bottom of the plates, which will ruin them.
When you refill the cell, the electrolyte reaches to the top of the
plates, so the battery works, but only for a short while until the top
of the plates are ruined too.
Randall
Betti Ann & Preston Smith wrote:
>
> One cell was dry so i added distilled water and slow charged it
> again. I have nothing to check the specific gravity but my digital meter
> shows 13.08 v across the posts.
>
> Does this reading signify a good battery (or bad) battery?
///
/// shop-talk@autox.team.net mailing list
/// To unsubscribe send a plain text message to majordomo@autox.team.net
/// with nothing in it but
///
/// unsubscribe shop-talk
///
///
|