"feetwet" wrote in message
news
My boat has an Interstate Lead-Acid RV/Marine Battery the dealer installed
this spring. When I picked up the boat with this battery I noticed the
voltage was low (probably around 11.5 v?). I've charged it since, but it
seems to lose charge quickly.

I disconnected all leads from the battery for 3 days and it held 95%
without
drop. Once I re-connect the wires, it lost 7% charge in one day (95%
@12.75v
to 88% @12.63v), this seems like a lot of drop for not having any
accessories turned on. I'm certainily interested in a battery shut-off
switch... but perhas I should warranty the battery first?

Can anyone validate if this is unusually high capacity drop for a 35-40 ma
load (as measured by my digital voltmeter)?

Stepping right up to the group flame throwers here.......... Lead acid
battery capacity cannot be accurately measured by the open circuit voltage.
There could be a battery fault here, but the tests so far don't mean an
awful lot. Although the 35-40 ma current draw without anything turned on
seems a little high for perhaps only one or two pieces of equipment with
"push-button" electronic off/on switching, it is certainly enough to take
the freshly charged voltage down a fraction over a day's time. In most cases
the freshly charged open circuit voltage will fall a half-volt or so over
two or three hours as the battery cools.

Verdict? Hard to be sure, but doesn't sound too far from normal.

You really, really need to have (and use) a battery switch.

Let the flames begin.

Old Chief Lynn