[C320-list] Battery charger/inverter

[Warren Updike]

Re. shore charger capacity: for wet-acid batteries, the max. charge acceptance rate is about 25% of the total capacity.  Therefore, with 400AH, a 50A charger is not overkill.  A 30AH charger will work but just take longer to bring the batteries to full charge.  If you're plugging in overnight the time may not be an issue; but, be sure to factor in the existing load (refer, lights, fans, etc.) as that will reduce the charging going to the batteries.

For those interested in battery/charging stuff, there is a great article in the Spring 2007 issue of "BoatWorks" mag authored by the pro Nigel Calder.  (A great reference for DYI projects; $10/yr, www.boatworksmagazine.com.)  The article and the accompanying sidebar is the clearest explanation I've seen yet of the alternator charging process, and how to improve it.  One interesting point is the effect of voltage drop on the process: just what Jeff Hare has been telling me since I started my alternator upgrade project.  My birthday is coming up and Nigel's book is going to be top on my gift list.  On page 19, same issue, is a Q&A re. an old shore charger that is also interesting.

Warren & Pattie Updike
C320, #62, 1994, "Warr De Mar"
Frog Mortar Creek, Middle River
Chesapeake Bay