Battery Orientation

[TimFromLI]

I am replacing three 4d AGMs with 6 Trojan T-105s. Because of the height of the batteries, I have to do some modifications to the battery compartment. I thought I had it all planned out until I found this old post on battery orientation which recommends that flooded batteries be oriented port/starboard:

Installation & Orientation of Flooded Batteries

Port to Starboard Orientation In the photo below I am simulating a sailboat heeling with flooded batteries. For years I have been wanting to write this article but until my friend Dave let me shoot these polycarbonate cased UPS batteries it was going to be tough to explain. A picture is...

forums.sailboatowners.com

Does this still hold true? If so, I have a bit more modification to do. My other question is how level does the bottom of the compartment need to be. The bottom of one of the two compartments slopes slightly from aft to forward. I am about to remove my inverter /charger and most of the battery wiring to correct that.

 

[dmax]

Still true - if the slope is more than a couple of degrees, I would attempt to "level" it.

 

[Tally Ho]

I am replacing three 4d AGMs with 6 Trojan T-105s. Because of the height of the batteries, I have to do some modifications to the battery compartment. I thought I had it all planned out until I found this old post on battery orientation which recommends that flooded batteries be oriented port/starboard:

Installation & Orientation of Flooded Batteries

Port to Starboard Orientation In the photo below I am simulating a sailboat heeling with flooded batteries. For years I have been wanting to write this article but until my friend Dave let me shoot these polycarbonate cased UPS batteries it was going to be tough to explain. A picture is...

forums.sailboatowners.com

Does this still hold true? If so, I have a bit more modification to do. My other question is how level does the bottom of the compartment need to be. The bottom of one of the two compartments slopes slightly from aft to forward. I am about to remove my inverter /charger and most of the battery wiring to correct that.

Yes, depending on your battery choice.

It has more to do with the orientation when heeled over...and the acid not covering the plates if oriented bow/stern.

Greg

 

[Mark Maulden]

I'm tending to think that if the water level is to the bottom of the vertical sight slot, or a bit higher, that the orientation shouldn’t matter much. If you are heeled so much that this occurs, you are probably bouncing around a bit which would keep plates wet. I would keep them level with the boat being level. And, if I’m wrong, what percentage would I lose?

 

[mermike]

I would think that uncovering any part of the plates is going to damage them. How much capacity loss will be hard to quantify. Perhaps AGM would be a better choice here, assuming you're not already committed.

 

[Maine Sail]

This is actually part of the ABYC Standards..


"10.7 INSTALLATION:
When installing flooded batteries on a sailing vessel, consideration should be given so that the orientation of the battery minimizes the uncovering of battery plates while heeling."

 

[JamesG161]

Minimizing uncovering plates = longevity of batteries.

Hard charging, while a plate is not covered, is worst case.

I am impressed at my Hunter's battery compartment.

1) Near the Center of movement of boat [Fore/Aft and Port/Starboard]
2) Well vented
3) Easy access to maintain and remove/replace.
4) Oriented Port/Starboard.
5) Close to Boat Ground Buss
6) Sized for 2x8D
7) Level at berth.
8) Less than 3 feet from the Smart Charger.

I made this list since there are more to consider than just calm sea leveling.
Jim...

 

[JamesG161]

This is the "Broker" pictures 2012 of 2x8D by the Previous owner.
I now have 2x4D
I show this since the Engine and Batteries are aligned on the Centerline of the boat.
The plates will be exposed in heavy seas, no matter Port/Starboard.
But plate exposure is minimized.

Jim...

 

[DougM]

Its difficult with a sailboat to keep batteries anywhere near level with the boat heeled over (says captain obvious..).

My boat has flooded batteries in the OEM locations. One is port to starboard in front of the engine and the other fore/aft adjacent to the prop shaft. I suppose if one really wanted to get fussy about mounting they would have to create some form of a gimbal mount.

 

[Maine Sail]

These may help:

https://marinehowto.com/installation-orientation-of-flooded-batteries-on-boats/

Also:

https://marinehowto.com/what-is-a-deep-cycle-battery/

 

[TimFromLI]

This is the "Broker" pictures 2012 of 2x8D by the Previous owner.
I now have 2x4D
I show this since the Engine and Batteries are aligned on the Centerline of the boat.
The plates will be exposed in heavy seas, no matter Port/Starboard.
But plate exposure is minimized.
View attachment 176648
Jim...

I think that is the proper orientation for 4Ds since the cells are aligned differently in 4ds

 

[TimFromLI]

Well I dismantled the starboard battery compartment to find that the plywood bottom is glued down with 5200 (that battle will probably be another thread). The port battery compartment is identical minus the glued plywood bottom. I should be able to fit three T-105s in each side oriented port/starboard. However, that means the jumper from one of the T-105 will need to travel 4 feet or so to join up with it's partner in the port battery compartment. Assuming I size the jumper correctly (any advice on wire size there would be appreciated) would there be any problem with having them that far apart?

 

[JamesG161]

I think that is the proper orientation for 4Ds since the cells are aligned differently

The 4D's and 8D's are the same cell alignment. Port/Starboard.
The Middle cell will stay flooded in Fore/Aft heavy seas.

But think of 10' seas, who really cares about battery longevity then.

Use thinner painted plywood in Port compartment.

Wire size is determined by length and Amp load.
Jim...