ON Board Chargers

[bluefin56]

Hey guys,

I have three batteries on board my boat at present. One for my main motor and accessories like radio, nav lights, bilge pump and voltage monitor. One for my electric trolling motor, and one for my live well pump. If I was to install an onboard charger, how much amperage per bank should I get, and how much would I be looking at as far as cost?

Thanks, Bluefin56

 

[galamb]

I run a 3 battery set-up - one "cranking" battery for the motor and two "house" batteries (grp 27 deep cycles @ 90 amp hours each).

I recharge with a 20 amp, triple output, Pro Mariner, Pro Tech charger (retails for about 330 bucks).

It's a (smart) charger so it can send more "juice" to the battery that most needs it and will switch to a float charge when they are all topped up.

It's one limitation is that you have to use 3 (similar) batteries - either ALL flooded, or ALL AGM etc, you can't mix and match.

So depending on how quickly you want to recharge and how many amps you want to "put back", that will determine how much charging power you need.

In my case it is pretty much just the house batteries that need the charge time - the charge stator on the motor keeps the starting battery topped up and does provide a bit of a charge to the other pair through the charge relay (but usually not as much as gets taken from them - especially running stuff at anchor).

So in a "worst case" I need to replace 180 amp hours worth of power during an overnight period - a 20 amp charger would need 9 hours to do that - so 20 amps works for me.

You need to figure how fast you want to recharge and how much you need to "put back".

You can get a decent 10 amp charger for around 100 bucks. If you want to get really fancy you can easily drop 500 or more on a charger...