Fitting more batteries

[kevin27]

Hello,

I have an '88 where the battery compartment fits a group 24 and a group 27 side by side.
I'm looking for ideas for expanded house capacity. AH numbers are totals at 12v.

1. I think a 4D (160 AH) can fit where the 24 and 27 (80 AH) are, maybe with a little modification because
another inch of width is needed. Then a 24 start battery can go behind the engine.

2. There is a lot of room in the lazarettes. Two Trojan GC2 (450 - 520 AH depends on model) golf car batteries
would fit well on the plywood that supports the fuel tank and water heaters, one on each side. An L16 6v (720 AH)
battery would fit on each side as well but that's a little crazy, hard to box and hard to strap down.
(And heavy!) But if you needed a big bank, the height is there.

Has anyone expanded beyond having a 24 + 27? Thanks.

[wes]

Kevin - I can' really speak to your ideas, except to say I'd be cautious about shifting a lot of battery weight further aft.

I've just posted separately about how to install two group 27 AGMs. For my purposes I feel the resulting 178 Ah of capacity will satisfy my needs.

Wes

[moonlight]

I recently did a job for a 36' Californian Trawler.

Removed four 8D (245Ah, 165#) batteries that were inaccessible, outboard of the engines.

Installed a 14"x14"x14" cube of LiFePO4 which comprised two 12V, 200Ah banks weighing 88# a piece.

Total usable amps = 320.

Still sorting out the rest of their wiring irregularities (the owner had installed a new aft bilge pump with float switch, but couldn't get it working.  Because the trailer cable (that's right, brown/green/yellow) didn't have any voltage.  Not to be confused with the other trailer cable, which was to the starboard fuel tank sender (NO, that should be PINK wire).  Ugh.

Anyway, since he has two 120A alternators, once I get it all sorted out, he'll be able to invert off the bank and run air conditioners off the alternators ... toss the generator overboard (except for when he wants air conditioning without engines, but he's considering enlarging the battery bank for those times...)

(I have other boats running air conditioners off inverters; formerly by 4xGroup31+4xGroup55 AGM batteries, or a total of 660Ah & 480#.  This was replaced with 115# of LiFePO4 which fit in the space formerly occupied by only the 4xGroup31 AND is 480Ah which is actually more useable energy than he had with the AGM)...

[relamb]

I have the two under the step, 24 and 27, then added a third 27 deep cycle battery behind and to the starboard of the engine.  There's a plywood divider around my engine to keep stuff from the compartments from sliding into it.  The battery is located inside the rear starboard quarter of that barrier.  There is just barely enough room in front of the battery to close the engine intake through hull valve.  I had to make a plywood base similar to what the fuel tank sets on, glass it in, and added tie downs.

[kevin27]

Thanks. Two 27 deep cycles have the capacity of a 4D so it's nice to know some brands will fit in front of the engine. And behind the engine is a nice spot for a 24 for cranking. I thought about weight distribution but didn't see why more weight down low would be a big problem.

[Allure2sail]

HI:
I have two group 27's under the stars (eliminated plastic battery boxes) and one group 31 in a battery box under the vbert on the starboard side. Use a solar panel and regulator to keep it charged. It is only used for the windless and not connected to the pair of 27s under the stairs in any way. Did not see any difference in how the boat handles. I am currently shopping for a bigger boat and may put Allure my 27 up for sale this summer !! Have to find another boat first, looking at Pearsons, Catalinas and Odays in the 30 to 34 foot range. Nothing yet.