Looking for advice on batteries placement.

[Wisakedjack]

I am looking for some advise on batteries placement. May boat ('76 Catalina 30) has two batteries which were sitting on a wooden shelf on the port side in the engine compartment. During the offseason the shelf broke from the mound of 5200 it was secured with. I did give it a nudge to see how secure it was and I consider myself really lucky it did not happen during sailing. So, I decided it was a good time to redo some wiring and rethink battery positioning in the process. In general I am looking at a simple setup with one starting battery and one house battery. Something similar to what Neil posted a while back. Basically separate circuits for starting and house batteries. House will be charged by small solar panel and starter will be charged by the alternator. I am not going to combine them using ACR. My electrical panel is located near the ice box on the port side. My boat sits on the mooring, so I don't have access to shore power. I currently have 2 group 27 wet cell batteries, which are old but may serve for another few years. So, I have some constraints on how they should be oriented. I may add another battery to the house back in the future, but currently I don't see the need. So, here are the options I am considering:

1. Make a new shelf and glass it to the hull in the old location in the engine compartment. I was wondering if that space is better used for fresh water cooling that I am considering adding in the future? I am not sure how much space it requires and where people usually mount the components.

2. Move both batteries under nav table. The space there allows to secure batteries well and opening is big enough for two batteries in boxes. However, this will mean a longer cable run to the engine.

3. Put starter battery under the port side settee and house bank into the port side lazarette. This way starter battery can be secured easily and will be close to the engine. House bank will be close to the main panel.

What do you guys think about these options? Is there a better solution that I am overlooking? I read a lot of posts on this forum and a long write up on C34 forum. Most of them focus on wiring, but my big concern is finding a good solution for securing the batteries. Ideally something that could be accomplished without having to do too much glasswork. Any advise would be greatly appreciated.

[ndutton]

I recommend a hybrid approach of your options #2 & 3. Engine starter near the engine to minimize the cable length and potential voltage drop with the heavy starter load and the house battery under the chart table to help offset the natural Catalina 30 port list.

[Wisakedjack]

Thanks for your advice Neil. I did think about Catalina's port lisp, but hoped I would offset it by having all my water tanks on the starboard side. But I do like your suggestion. I've read your posts and know that you favor wet cell batteries for their robustness. I am toying with an idea of switching to AGMs, which will allow me to place them under the settees parallel to boat's centerline. I keep thinking this is the ideal location with settee wall on one side. I would still need to make some shelves, which is also the case for under nav table location. Do you have any suggestions on how to do it? Glass them to hull or bolt through side walls?

[ndutton]

It depends on your skill set. I'm experienced with fiberglass so that would be my preference, a 3/4" plywood shelf glassed to the hull. If you change your mind re: battery type, wet lead-acid batteries require ventilation for safety so that may factor into your choice of location. You don't want a hydrogen gas bubble gathering anywhere.

[Wisakedjack]

Thanks again Neil. I have experience working with fiberglass. In fact I love doing glassing projects. But I want to make sure my solution would not be an overkill. Besides FG leaves a permanent mark on the boat. So, its nice to get a second opinion to make sure that what I am doing is reasonable

[roadnsky]

One more thing to consider in choosing the location...

Remember that eventually your needs (or the needs of another skipper) will change.
ie. You'll decide to add another battery to the house bank.

Thinking that thru now and planning for it may make you look wise later.

[Wisakedjack]

Yes, I am considering expandability. I found this post:

https://www.moyermarineforum.com/forums/showthread.php?t=5040

where similar project was done on same boat as mine. I like how the batteries fit under the starboard bench. I think I will do just that and keep the starter battery close to the engine under the port settee like Neil have suggested. I have to think about battery orientation, so that both AGM and wet cells could be used. But all I need to do for that is replace plastic battery box with tie downs.

[sastanley]

Whoa...cool..that is my thread, and I didn't quite finish it up.
Here is the (almost) finished product..I hadn't painted the glass work yet. I am happy with the re-wire project, however, I am considering bumping the main wires to #2 because I do sometimes trip the 100amp main breaker..and I think upping the wires to the engine may help with voltage drop for the long run.
Here is a pic of all the batteries in place..2 wired in parallel for house + gr24 start. I also like the hybrid approach where you could put a start batt close to the engine.

I am not sure how people jam batteries under the nav table..mine are under the settee. Where is your main panel now? Mine was near the ice box originally, and I put a Cat42 panel in my re-built nav station during the re-wire.

[ndutton]

I have to think about battery orientation, so that both AGM and wet cells could be used.

Please reconsider this plan. Different battery chemistries require very different charging voltages and profiles. Mixing battery types will result in one of the types being unhappy and performing poorly.

[Wisakedjack]

Please reconsider this plan. Different battery chemistries require very different charging voltages and profiles. Mixing battery types will result in one of the types being unhappy and performing poorly.

Neil, I did not mean mixing AGM and wet cell batteries together. Rather using one type or another, but having mounting positions that would allow to use either type.

[Wisakedjack]

I am not sure how people jam batteries under the nav table..mine are under the settee. Where is your main panel now? Mine was near the ice box originally, and I put a Cat42 panel in my re-built nav station during the re-wire.

Shawn, thanks a lot for the pictures. They were very helpful. My main panel is near the ice box. My nav table is angled, so there is no much vertical space to put main panel on top of it. In addition that location was prone to water leaks in the past (hopefully fixed now).

I can put two batteries in the nav table if I remove the bottom shelf there. The opening is almost perfect size for 2 group 27 batteries.

[ndutton]

Neil, I did not mean mixing AGM and wet cell batteries together. Rather using one type or another, but having mounting positions that would allow to use either type.

My misunderstanding, sorry.

[sastanley]

w..jack,

Yeah...mine was too. With some help, I rebuilt my chart table to accommodate the eBay panel, give me a flat surface, and re-wired the entire boat in the process. However, one note, I still ran a 12v feed to the old panel for many seasons while I slowly relocated old circuits (i.e. running lights) - it took a few years to get those new wires run to the more remote areas of the boat. I still don't have any cabin lights on the stbd side of the boat, except in the v-berth.

One more note. My Gr29's are the same foot print as a Gr27 I think, just a bit taller...they barely clear the settee, but they fit..not sure if they would fit under the chart table..I store too much junk in my chart table locker, so I didn't want to put batteries under there that I could not get to easily.

[Wisakedjack]

Thanks Shawn! You did really nice job with that rewiring project. I wanted to ask you one thing. I saw in your earlier picture that you battery tray was screwed into those pieces of wood on the sides. Are you still doing it or do you have a solid shelf to support your batteries. You are also right about tight fit under the settee. I currently use battery boxes and those don't fit. However, if I turn the batteries 90 degree compared to your orientation they fit well. Problem is I can't install wet cell batteries like that. I can do that with AGMs though. So, this is something I am considering. But I do agree with Neil that wet cells can take a lot of abuse and provide a very robust solution. We'll see....

[sastanley]

I am not always good about taking critical in-the-moment pics.The boards are actually PVC board. I mitered the edges as close to the hull contour as I could get them. They were 3/4" x 3" or so...glassed in longitudinally, with West epoxy to secure them to the boat. What you cannot see is on the inboard side of the settee, I glassed in 1 inch wide blocks that were vertical to give me something to screw the battery boxes into on that side too. The top of the verticals matched the height of the 3/4" outboard support boards.

In hindsight, I might have done a similar build, however, I might have run the PVC boards athwarthships and glassed the whole thing in. I will keep digging to see if I can find more pics.