Battery charger coice

[BonesD]

Howdy, I need to buy a new battery charger for two seperate batteries, both 1131MF 950-RC 1.75.
I’m looking at the Promariner 44020 or the 44021.
Both are rated at 20 amps but one has 2 outputs vs 3. The price is almost the same so I thought the 3 bank version would give the room to expand if needed. Would this output amperage be suitable for my batteries.
Thank You

[donradcliffe]

It depends a bit on your house loads, how much time you spend on the boat, and how much time the boat is plugged in. For instance, if I had a large inverter and microwave or on a mooring and only plugged in occasionally, I might go up to a 40a charger. If I was a weekend user and the boat was plugged into shore power when I was not using the boat, either Promariner would be fine. Not too many boats have 3 battery banks unless they have a bow thruster.

[Sailmonkey]

What are your DC loads?

With a 43’ boat it’s quite possible that you can exceed 20amps of draw. Do you spend a lot of time on the boat at the dock?

[BonesD]

Thanks for the replies. Forty foot boat
No inverter
I am a live aboard on a dock and hooked to the shore.
My dc loads are mostly led lights which are seldom used here in the PNW.
When I am out cruising the auto pilot is drawing but the alternator keeps up with it when motoring. It makes me a bit nervous though when running long under sail. So far I have not done much of that but will be cutting the cord asp. Add depth finder,vhf, radar, and ais the draw adds up although I can’t imagine these things pull to many amps. The wiring is to small to demand much. Even the radar power lead isn’t more than a 16 gauge wire at best.
I may add a third battery to one of the big 12s in parallel to run this stuff and save the third for starting purposes.
Pretty simple set up but it amazes me how much wire there is on this boat!