batery charger question

[nolasailor]

hello all,,, Doing a complete rewire on a 31 niagara sail boat. Will post pics soon,,
Batery bank design will be one starter batery isolated from the house bank which will be two batteries...
Will a two bank battery charger work, one bank for starter bat, and one bank for the two house bats, or do i need a 3 bank charger one bank per battery. All batteries are new, and the two house bats are matching.
and any suggestions on brand and amp size,,, thanks,,,, Kevin

[mitiempo]

A two bank charger will work because the house bank is 2 batteries in parallel - seen as one larger battery by the charger.
As far as size, how large are the batteries in AH? Will you be living aboard? If so, and you are consuming 15 amps and the charger is a 20 amp charger the batteries only see 5 amps. If you are not living aboard the full 20 amps is available to charge the batteries.
How will you be wiring the alternator output? The system that makes the most sense is direct to the house bank. This avoids the problems with charging current going through the 1/2/both switch. The start battery is taken care of with either an ACR or an Echo Charge automatically. If this is done your AC charger only has to service one bank, the house bank.

[sailingdog]

You're much better off getting an ACR/EchoCharger/Duocharge unit and using a single bank charger. The multiple bank chargers are not as reliable or robust as the single bank chargers as a general rule. Also, by using an ACR/Echocharger/DuoCharge unit, you will greatly simplify your life and your wiring of the boat's battery banks with respect to non-shorepower based charging. Just connect all the charging sources to the house bank and let the ACR/EC/DC unit take care of the start bank.