Re: Batteries

jjwiggin02 <no_reply@...>

--- In, "Ian & Judy Jenkins"
<ianjudyjenkins@h...> wrote:
On our SM, 302, June 2000 launch, now lived aboard for 18 months,we
that at sea we run the genset about every six hours for an hour to
an hour
and a half on each occasion. Less when at anchor without autohelm,
lights radar etc.Our first batteries ( we have 420 amps) lasted two
since when I tend to recharge when we are down to 90% ( We found
that the
fridge cut out somewhere below 87% notwithstanding the fact that we
had 24v).
I find that the recharge quickly up to 99% but that those last few
amps,say the last 7, take for ever.
Does anyone know how important it is to always recharge to 100%?
The one thing I would suggest when running the genset is to check
that the
220v fan is working ( put your hand over the outlet in the cockpit
) Ours failed in the Caribean and the extra heat in the engine room
appparently the reason why our 50 amp charger failed after 3 years,
to be
followed by the 30 amp one ten weeks later.This, despite the fact
that both
chargers have heat cut outs.The first failed in Guadeloupe and was
the knowledge of Pochon for a speedy repair.but both were repaired
by Manuel
in Ecuador ( thank God for the third world--they still know how to
things there).He said he had never seen anything so hi tech and
powerful in
such a small box--the last time he saw such a powerful gadget it was
size and weight of his mother in law!
The cost of a new 220v fan ,one new 50 amp and two repairs was
and I don`t understand the need for the 220v fan. The two 24v fans
are much
more powerful,give you an element of redundancy, much cheaper and
can be
sourced anywhere.Is there a good reason why they could not be wired
up to
come on with the genset just as they come on with the Volvo/Yanmar?
Ian. Pen

If you are trying to charge to 100% you will be running your genset
far more than necessary. Conventional wisdom is that it is bad for
the batteries to go below 50% and that above 80% further recharging
becomes increasingly less cost-effective. Therefor an optimal program
would be to dischage to 50% and re charge to only 80%. Crossing the
Atlantic 19 days with 6 people, radar on most of the time,
transmitting daily on SSB, two refrigerators and a freezer, we ran it
for 1 to 1 1/2 hours twice a day.

Hope this helps,

Jim Wiggin, ANTARES, Amel SM
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