Mainship Pilot 34 House Battery Addition

[ewandeane]

Hello people of the forum and fellow Mainship owners

I am adding a house battery bank to the boat, currently there is a single 8D for the engine start, house usage and thruster. We also have a group 24 for generator start.

We plan to spend more time away this year and want to add a separate house battery bank. Space is a little limited, we will utilize the storage area under a settee in the exterior salon.
We really only need the bank to keep the fridge on, lights (all LED), vacuflush, phone chargers etc.
My mechanic is suggesting to add a second 8D for the house side and beef up the charger.
I am concerned about how low we can drain it, and if the amp hours are enough. Should we go 4x 6V golf carts?

Any other Mainship owners want to chime in with their systems? More knowledge the better.

I have read a few of the battery posts here, but its hard to relate them to my needs, plus electrical systems I find challenging.

As usual, appreciate the feedback.

Ewan.

 

[DavidM]

Scrap the 8D and replace it with a good G31. Then set up a separate house bank of two GCs. That is what we had on our Pilot 34 and it all fit under the aft sole. With a generator you don't need so much house capacity. We would need to run the generator for coffee in the morning or hot water at night. With a half hour of running morning and night that kept the house bank charged up.

David

 

[ewandeane]

David,
You were able to get batteries in the aft sole? The access hatch is not great, and the center line storage has the shaft there, the port and starboard side are pretty hard to get to. Impressive on your part. I think I will go with something easier to get at.

 

[Bacchus]

I'm with DavidM and plan to scrap my (3) 8Ds on my MS 34HT as soon as they need replacement. No advantage for 8Ds and more than one negative.
My plan is to move start to my thruster bank (done) and install a pair of Gp31s.
That will leave my house bank pure house - If you are staying with FLA I'd go with a pair of 6V GCs in series for house.
If you compare I think you will find a pair of GP31s provide about the same CCA as an 8D and a pair of GCs provide roughly the same AH as an 8D
My (3) 8Ds are AGM and I will replace with AGM but plan GP31 AGMs for all - 2 - start / thruster and 4 for house.
My research w/ East Penn indicates AGM GP31s are as good at deep cycle as AGM GCs.
Like you I have a gen w/ separate batty as an emergency back-up. I can easily jumper my house to start if needed in an emergency