T&T: Charger/battery problems?

[Paul Brannon]

I have an interesting situation I need help with.  A fellow boater has 3 8D
batteries as a house bank and 1 8D as a start battery.  The house bank is
driving a Xantrex MS2000 inverter and the start batteries for the main and
genset are charged by a Xantrex Truecharge 40.  All of the batteries are new
(house bank is only 2 days old).  The inverter/charger on the house bank is
charging but changes to absorbtion and then to float rather quickly with a
current output of ~10 amps.  The problem is that the hydrometer is reading
around 1.2 (upper "recharge" range) for specific gravity.  The start battery
(different brand) is reading 1.3 (top of "good" range).  The charger acts as
if the batteries are fully charged but the hydrometer says differently.  We
tried connecting the Trucharge to the house bank independently with all other
connections removed and it also went to the 10 amp range rather than 40 amps
(which it should have done if the batteries are actually at 50% per the
hydrometer).  Two different hydrometers read the same.  So, the question is,
is it possible to have the batteries actually near full charge such that the
chargers are reduced to float and have the hydrometer read low?


Paul & Stacy Brannon
m/v SEASEA
1978 Gulfstar 44 MC