At 02:23 PM 4/16/2009, neil N wrote:
>Charged the aux. battery, then left "intelligent" charger connected to
>battery overnight. Charger was off. Battery got quite low.

Not likely.  Can't say it's impossible.

But easy to test.  Hook up your ammeter on 2-amp (2,000-ma) or 10-A
range between charger and battery, charger off.  If you don't have
half an amp or so drain then not the charger's fault. 50 ma is trivial.

If you exonerate the charger, take the ground terminal off the
battery and put the ammeter in series there, everything turned
off.  If no drain, then your cat sneaked out and turned something on
in the night, and the dog turned it off again.  If there *is* a
significant drain, pull fuses one at a time until it stops, then
evaluate your situation.

  --
David Beierl - Providence RI USA -- http://pws.prserv.net/synergy/Vanagon/
'89 Po' White Star "Scamp"