boiled batteries

[birdshill123]

Our 88 FC is equiped with 6/ 6 volt batteries. 4 on the drivers side
and 2 on the passenger side. They are wired together and supply both
coach and engine power. They are probably nearing the end of their life
cycle as they are almost 6 years old. I always have to add a lot of
water. My alternator is a Powerline. I think 200 amps. THis mother has
an internal regulator. I spoke to Powerline and they told me to adjust
the voltage to 14.2 with fully charged batteries. It was putting out
15 volts. For some reason it starts out at just over 14 volts but then
after driving awhile it goes back to 15 volts. Strangely the ammeter on
the dash shows almost 75 amps at 14 volts?? I recently changed all my
battery cables and cleaned all the ground connections as well as the
shunts ( 3 I think) in the DS battery compartment. Another anomaly is
that the DS batteries will be boiled almost dry and the other 2 take
only a little water??? I dont want to buy new batteries until I have
solved this problem. Any help appreciated.


Bruce

88 FC35