Re: chargers for dockside (or generator) use, it's hard to beat the Iota
chargers, with IQ-4 smart controllers. They are very robust, virtually RFI free, use pulse-width modulation technology, have automatic equalization
capability, and are relatively inexpensive. They come in 15, 30, 45, 55, 75, and 90A versions. For a 400AH battery bank, a 55A or 75A would be appropriate. Be sure to get the IQ-4 option ($35). You can find them on eBay and through various marine
Re: solar panels
, the more the merrier. How many and how much capacity would depend on your intended use (cruising practices) and location.
Re: batteries, many sailors prefer to use 6V golf-cart batteries in a series/parallel arrangement. Four of these would give you 450AH capacity. This is probably one of the most economical ways to get that kind of capacity in a true deep-cycle battery bank.
Re: the question on one large bank vs. two or more banks, yes, it's true that this is a fairly recent accepted practice. Many older boats, including mine, were wired with two banks through a 1-2-both switch. I'm convinced that many were done this way just because they didn't know what to do with the switch if you didn't have two banks :-)
One large bank is preferable for the reasons cited above. If you like, you can set up two banks (equal or unequal capacity...it doesn't matter so long as the battery types are the same), and use them mostly as one large bank by leaving the house battery switch in the "both" position. This is how it's done on my boat, and it works well so long as you use BIG battery cables
, have really good connections, and have a robust battery switch.
Re: a separate starting battery, yes, that's almost always the most desirable thing to do. Keep the starting battery completely separate, and charge it using a device like an EchoCharger which senses a charge on the house batteries and bleeds off enough to keep the starting battery fully charged. EXCEPTION: if the motor
is just an outboard and is easily started by hand -- as in the case of the original poster here -- then it might be economical to simply use the house bank for engine
starting and not have a separate starting battery setup.
S/V Born Free