CD30 battery box replacement

[jbenagh]

I'm thinking of upgrading my battery capacity on Christine C, my 1983 CD30. I'd like enough house capacity to run essentials (radio, lights, foghorn and radar) for the ~30hr trip to Maine without running the engine. I presently have one group 31 for the house and one group 24 for the starter. Either one can be switched in using a standard 1/2/all/off switch. I've already relocated the existing two batteries to the front of the starboard cockpit locker after moving the water heater under the cockpit sole. I plan to add an ACR charging relay no matter what.
I'm thinking of two 31's for the house and the 24 for the starter. I'll build a battery box to locate atop the old water heater shelf out of 1/4 ply, glass mat and epoxy. I'll firmly attach it to the existing water heater mount and provide some good tie downs for the batteries. I might also just do Coosa instead of ply since I've seen the effect of battery acid on ply and think I'd prefer more chemical resistance. In the horizontal space, I can fit all three batteries with room for cables and such. Only problem is, I cannot fit the assebled box through the cockpit locker. It seems like I can fit in the box about 2/3 height and then could glass in the upper part. The box I have in mind is almost exactly the size of the 20 gallon diesel tank but the locker opening is smaller than the port side.
What do you all think is the best way to get the box in place? Seems like I could:
1) put all the ply pieces in the locker, assemble them, glue them and then glass the inside.
2) build the bottom half of the box, get it in the locker, attach the upper part, then glass everything in
3) as #2 but glass the bottom part before the install
I think #3 might be best as the most likely battery failure is 1-2 cells and the glass would be more secure this way. Also I could make much better tie downs working on the workbench rather than inside the locker. I think there's not much difficulty difference between 1 & 2 so I'd probably go for 1. I might try to get the bottom plate built first with the tie downs and the external attachments built.
Jeff

[tjr818]

Why does the battery box have to be so deep? I thought the only purpose was to contain any spillage. Think about having to lift a Group 31 up into the box, that can be difficult. Are you going to use plastic battery boxes too? I prefer the plastic battery boxes with lids strapped to a robust shelf with just a one or two inch lip and good tie downs for the boxes.

[Jim Walsh]

I’ve added a battery shelf and a standard battery box is held on it with a strap. The shelf is glassed to the aft starboard cockpit locker in what was essentially unused space. The orientation is athwartships as is preferred with flooded batteries. The shelf is constructed of 3/4 inch ply (with essential help from a skilled carpenter). The fiddles are an exterior decking hardwood with slots for the strap. The entire box was fastened with stainless screws and coated with epoxy before bedding in place and fiberglassing to the hull. I haven’t run new battery cables yet, I’ll do that in the spring. I’ll also add a coat of bilge paint for appearances sake.
Orion has always had two batteries, a group 27 and a group 31. I’ll now have a second group 31, doubling my house bank capacity.

[Steve Laume]

I also put my replacement water heater under the cockpit sole. This freed up the shelf for batteries. Before making accommodations for the batteries, I trimmed (cut away a big chunk of) the shelf to allow much better access to the cockpit drain, seacock. Raven has two group 27 AGM batteries that are treated as one as far as charging and use are concerned. I mounted a Group 24 start battery down low to the hull, just behind the seacock and close to the access panel to the engine. This keeps some of the weight a bit lower and closer to the center line while staying as far forward as possible. I simply added cleats and a heavy tie down for plastic battery boxes. It is hard enough to get the batteries out as it is. Mine are right up against the cabin bulkhead and I could not lift them out of a box,

This situation seems to rest firmly in the don't make it harder than it has to be category, Steve.

[jbenagh]

Thanks for the feedback! Maybe I need to reconsider my plans. I do like the idea of improving access to the seacock.

Jeff