Glenn Ashmore wrote:
I was talking to an engineer with a local school bus manufacturer
yesterday about Rutu's progress. I mentioned that I was leaning
towards a high capacity Group 31 battery to use for the starter bank.
More than the 4JH4 needs but would give me a lot of reserve. He
replied that was a bad idea on a sailboat. Seems that they no longer
equip their school busses with 925 CCA Group 31's because they have a
very high self discharge rate. They are great for regular highway use
but school busses like sailboats spend a lot of time with the engine
off. The 620 to 700 CCA batteries hold their charge much better and
will last a lot longer in that type service.

Just another tidbit to store away for future use.

Glenn, thanks for the info. I targeted Gr-31s as my battery
because they are cheap & readily available... the last bunch
I bought were no-maintenance types from the 'Batteries Plus'
outlet, re-labelled Exides.


Jeff wrote:
I've used AGM's for my starting batteries. The self discharge is very
low, and the cost isn't that high.


I haven't found AGMs for less than about twice the price of
'dual-purpose' Gr-31s, which are about $60 at the
farm-n-truck supply.

OTOH I'm surprised Glenn isn't buying Surrette batteries for
his boat.

Fresh Breezes- Doug King