Battery Question

[George Forrer]

Hi Guy’s
I am looking at changing my 8D batteries. They are in a bad spot and to heavy for me to be dragging around. I was thinking about 4D’s or wiring two group 31’s together? The motors are QSC 8.3. Does anyone have any suggestions on what is the better way to go. The generator and battery charger are on the whole time the boat is away from the dock. Thanks George

Topic

[George Forrer]

Thanks guys for all the input. I think I will be going with the group 31 setup. I think I can manage those the best.

[Roger Franklin Williams]

Batteries

Have a 40′ Avanti with 2 Cummins 6BTA’s that had been wired with 1-8D for each engine 1-8D for house. Installed Inverter 15 yrs ago and put 2-8D’s in one house bank used 1-8D for engines. 10 years ago changed out all 8-D’s to 4-D’s and use 2-31’s in a bank for engines. Could use one 4-D also. Have cross over switch to combine house and engine batteries if needed.
Have tried glass mat and wet cells. I get 3 years out of InterstateDeep Cycle wet cells which for me have proven to be the best bang for the buck.

[james]

6 volt

My boat had monster 8d’s as well, and I coudn’t manage the. I ended up redoing the boat with the following: House 6 trojan golf cart batteries, wired serial to get 12 volt, then parelled into a single bank.

For starting I have 4 group 27 interstates. I always use the battery parallel switch when starting, so my engines are receiving the voltage of 4 batteries.

This does require that I water the batteries once per month, but my access is reasonable ok, and it encourages me to check different spots in the engine room.

[KevinS]

George – I got sick of moving 8D’s for my QSC8.3 and house bank as well. Last spring I did a complete refit from shelving, boxes, battery configuration to switches and charging system for better management and less struggle of moving 8D’s.

I had 1 – 8D for the start and 1 – 8D for the house. Both a PIA to swap out. I replaced all batteries (including my gen-set battery with DEKA brand wet cells. The QSC 8.3 requires 1250 CCA at 12 amps / 1563 MCA. I connected 2 Grp 31 batteries in Parallel dedicated and to the engine combined to 1400 CCA … plenty of crank and easy in and out.

I also had 1 – 8D for my house bank and for my type of boating it was insufficient. I switched this bank for 6 – 6 volt golf cart batteries wired in series and parallel creating a robust 12 volt house bank of 765 Amps.

Changing out batteries is now a Super Easy one man job and all batteries are for dedicated uses and not combined! I highly recommend this fix.

My NorthernLights gen-set would be satisfied with a Grp 27, but I opted for a 31.

I also took advantage of this project and added the Seaboard SMX Volt meters for simple battery management. This was the best part!

I hope that this all helps and gives you motivation to take making your battery management a bit easier.

Here’s a link to a topic that I started on my DC refit and the SMX Volt Meters.

https://www.sbmar.com/community/topic/smx-digital-voltage-monitors/

2 users thanked author for this post.

George Forrer, Rob Schepis

[Philip]

My boat is wired with 2-GRP31’s for starting/generator and 3-GRP31’s for house loads. This meets the Cummins spec for the QSC8.3 and provides plenty of power at night for a lights, 12v refegiation, bait pump, etc and I have the two engine/gen batteries for starting in the morning.

Lots of ways to set up your charging, some ways simpler than others. No right or wrong way as long as you understand and can monitor you charging status.

[Fireisland1]

I have the same problem . 8d glass mat are just too expensive. I put in new 8d’s with the help of a strong friend. That solved the issue short term. The problem is I can get into fill the cells and don’t want to bother friends. So I went to powerstridebattery.com . They make an auto fill system. You replace all the caps with valves that link all the caps together with tubing. You can then fill all cells from a remote jar.

1 user thanked author for this post.

George Forrer

[Author]

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