Relocate lithium batteries to bilge?

[sailingunity]

Last year we installed lithium batteries, my previous bank was in the engine room, and knowing what heat does to batteries I decided to relocate them. At the time, I was stuck between putting them under the floor in the salon, or in the workbench. I chose the workbench for a few reasons: I was worried what might happen if the bilge were to fill with water above the batteries, we have a lot of storage in the deep bilge which we'd lose access to, it's a bit shorter run to the charger inverter in the engine room, and I'd have to relocate the autopilot compass.

Let me explain our bilge however, it is very deep. The keel lead is in the bottom, then it's about 18 inches to the top of the stringers (this portion I call the "deep bilge"), I have a plywood floor on the stringers for flat storage. It's about 13 inches from the plywood floor to the salon floor. The 18 inch deep portion runs from the mast to the almost the back of the boat, under the engine the lead stops and the keel deepens all the way to the bottom (there's a bilge pump way down there).

We now have a list to port as the 3 batteries weigh in at 240 lbs. We can partly correct this by manually ballasting the starboard side of the boat, but that's not a permanent solution and the list periodically comes back (if we've eaten all of our canned food, for example). If all of us happen to be sitting on the port settee the list is even worse. I'm also thinking about repurposing the current battery space for a freezer.

So I'm wondering if my caution was overblown and it would be OK to relocate them. I know a lot of boats keep batteries below the floorboards, and in my boat it would take a lot of water to reach the terminals.

(photo of the kids helping me clean the bilge)

[sailingunity]

I should probably add that the batteries would not go in the "deep bilge" portion anyway, they would be sitting on the plywood in the upper part, under the settee you see in the bottom left of the image.

[newhaul]

Originally Posted by sailingunity

Last year we installed lithium batteries, my previous bank was in the engine room, and knowing what heat does to batteries I decided to relocate them. At the time, I was stuck between putting them under the floor in the salon, or in the workbench. I chose the workbench for a few reasons: I was worried what might happen if the bilge were to fill with water above the batteries, we have a lot of storage in the deep bilge which we'd lose access to, it's a bit shorter run to the charger inverter in the engine room, and I'd have to relocate the autopilot compass.

Let me explain our bilge however, it is very deep. The keel lead is in the bottom, then it's about 18 inches to the top of the stringers (this portion I call the "deep bilge"), I have a plywood floor on the stringers for flat storage. It's about 13 inches from the plywood floor to the salon floor. The 18 inch deep portion runs from the mast to the almost the back of the boat, under the engine the lead stops and the keel deepens all the way to the bottom (there's a bilge pump way down there).

We now have a list to port as the 3 batteries weigh in at 240 lbs. We can partly correct this by manually ballasting the starboard side of the boat, but that's not a permanent solution and the list periodically comes back (if we've eaten all of our canned food, for example). If all of us happen to be sitting on the port settee the list is even worse. I'm also thinking about repurposing the current battery space for a freezer.

So I'm wondering if my caution was overblown and it would be OK to relocate them. I know a lot of boats keep batteries below the floorboards, and in my boat it would take a lot of water to reach the terminals.

(photo of the kids helping me clean the bilge)

I see no issue as long as they are in a box that is water tight on bottom and sides at minimum besides I bet the ( let's call it ) high bilge is a lot cooler than even your main salon. Secure the bank on top of the lead ( great heat sink) the deep bilge is plenty deep so as if you get water filling most of your high bilge a foot deep and ingressing into the battery compartment the sudden water ingress is much more of a concern than what could happen to your bank if it gets flooded.
I vote go for it

[sailingunity]

Thanks. I'd hazard a guess I could probably fit one or two of these batteries (they are kilovault 300AH batteries, so they are pretty big) in the deep bilge, and if I built a waterproof box would even be safe in there. Just not sure how the cables would exit the box and keep it waterproof?

[sailingunity]

Something like this maybe.

[newhaul]

Originally Posted by sailingunity

Thanks. I'd hazard a guess I could probably fit one or two of these batteries (they are kilovault 300AH batteries, so they are pretty big) in the deep bilge, and if I built a waterproof box would even be safe in there. Just not sure how the cables would exit the box and keep it waterproof?

Waterproof cable glands

[gonesail]

I think the bilge shelf is a good idea. i want to do that in my boat. but the box sounds like a good idea too .. additional safety. I believe one of the members here put a battery bank in his bilge or keel

[sailingunity]

Does it count as extra ballast in the bilge? haha!

[newhaul]

Originally Posted by sailingunity

Does it count as extra ballast in the bilge? haha!

Well some do move storm anchors and chain to bilge for ballast so why not