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Old April 26th 04, 07:20 PM
Sheldon Haynie
Posts: n/a
Default Dual banks with Duo charge?

Thanks Larry, that would work well, IF the batteries were to be common
chemistry. Currently I have Flooded parallel-series connected 6V for House
bank and a small flooded for starter, Eventually I plan to change those
over, probably to an AGM for the starter. I do loan Lioness out and I want a
fool proof system.


On 4/23/04 11:30 PM, in article , "Larry
W4CSC" wrote:

Sheldon Haynie wrote in

Anyone have experience with dual banks (small starter and big house)
with the Balmar Duo-Charge? I am taking two seized up alternators off
a Westerbeke 46 (don't ask about why they are seized) and replacing
with a single 100A Balmar alternator. Rather than futz about with the
battery switch for charging, I would prefer to have a separate path
for charging so I do NOT forget to switch etc.

Sounds like a job for a 100A or more battery isolator, to me. Connect the
alternator to the common terminal of the isolator and one of the battery
banks to the output terminals. The diodes in the isolator will keep the
big batteries from sucking the guts out of the little starting battery.
The alternator will charge whatever batteries are low just fine.....

Because you say you are forgetful, I won't mention using a continuous-duty
solenoid relay to hook the house batteries up to the starting batteries in
parallel from a little switch at the helm. One boater I did some work for
was brainwashed that all diode isolators were like bubonic plague, which
they're not, so I mounted a 12V, continuous-duty, 250A solenoid relay
between the + on the house batteries to the + on the starter battery. At
the helm, I put a simple toggle switch marked CHARGE! with a BRIGHT RED
indicator in your face. The toggle switch wasn't turned ON until the
engine was running. The toggle switch to turn on the coil of the relay got
its power through a 3A fuse hooked to the engine power switch so you
COULDN'T leave it on when you switched the engine off, even if the switch
was left on. What was neat was that bright, red light. It was hooked up
ACROSS the toggle switch, not to ground. If you cranked the engine and
DIDN'T turn on the house battery charging switch after the engine cranked,
the light LIT! Turning on the house battery relay extinguished the bright
light and charged everything in parallel. It didn't make any difference
where you left the charging switch when you turned the engine off, as long
as you turned it off to disconnect dead house batteries before you turned
the engine switch on next time you cranked it. If the house batteries
weren't dead, you can just let the solenoid come on with the key to the
engine as it makes no difference and helps crank the diesel with all the
batteries pulling at once, which is where he leaves it all the time....on.

A great advantage to using the solenoid and not the isolator was there was
still enough power in an almost-dead starting battery to power the solenoid
if the starting battery wouldn't crank the diesel. Once "on", with the
house batteries now hooked up like jumper cables, the house batteries will
crank the diesel to kick it all into charge, dead starting battery and all.
The guy I hooked it up for simply loves the way it works.....(c;


Sheldon Haynie
Texas Instruments
50 Phillipe Cote
Manchester, NH 03101
603 222 8652