42: L42 - Best Location for Lithium Batteries

[Jim Woodall]

Has anyone investigated replacing the L42 batteries with Lithium? If so, any idea of typical ambient operating temperatures in the engine compartments, particularly in the starboard engine compartment? I've not done very much research but with the house batteries and chargers in the starboard engine compartment an upgrade to Lithium might necessitate moving the batteries and chargers to a cooler location. My understanding is that ambient temperature at or above 45C (113F) is very detrimental to the charging cycle and life of the batteries. I think the engine compartments are well ventilated, but I'm curious if they're well ventilated enough to drop the ambient temperature below 45C (113F). Obviously a few degrees below that threshold would be better.

I've seen recent posts from Impi and Starry Horizons (Out Chasing Stars) about this issue. Starry Horizons' battery bank (and chargers I think) were moved from the engine compartment to a location under a settee in the saloon.

Note sure how accurate this next bit is, but I read that getting the ambient temperature down below 105F puts one in a range in which the charging cycle and battery life will not suffer at all. I'm not sure if it's realistic to get enough ventilation in the L42 starboard engine compartment to even approach 105F.

[rom]

Would it be possible to install the batteries in a cockpit locker ? That's what I did on my L440, better weight distribution, easy access, and quite the center of the boat so I could eliminate lots of cables... I don't know the L42 setup though and I am suprised batts are in the engine room ! (I thought they were under an aft bunk on all lagoons)

[Jim Woodall]

Originally Posted by rom

Would it be possible to install the batteries in a cockpit locker ? That's what I did on my L440, better weight distribution, easy access, and quite the center of the boat so I could eliminate lots of cables... I don't know the L42 setup though and I am suprised batts are in the engine room ! (I thought they were under an aft bunk on all lagoons)

It seems that many of the production catamaran manufacturers are now placing the house batteries and chargers in the engine compartments. Brent from Impi mentioned it was a concession to the charter market. Perhaps easier access if charters are onboard and there's an issue with the batteries or chargers. Instead of taking over the saloon or cockpit and displacing the charterers only a transom step is being occupied for repairs. There is a good amount of space and it puts everything in close proximity. I'm not sure why it's becoming a trend.

[tuskie]

I wouldn't think an engine compartment is an ideal location for a LiFePO4 battery bank. Aside from the temperature issue that you mentioned there's also increased exposure to salt and water. Sometimes its necessary to open the engIne conpartment at sea and it does get seawater splashed in there.

At the very least the batteries would need to be housed in a weatherproof box. With an incorporated battery management system and cell equalizing circuits, a lithium bank is more like a piece of electronic equipment than a bank of old lead acid batteries. The smaller size, absence of gas output and reduced weight would enable installation in a more protected location.

[senormechanico]

Originally Posted by Jim Woodall

Instead of taking over the saloon or cockpit and displacing the charterers only a transom step is being occupied for repairs. There is a good amount of space and it puts everything in close proximity. I'm not sure why it's becoming a trend.

I suspect you answered your own question.
Bean counters from the charter companies influenced the builders.
"Hang the efficiency or long life of components, we just want return charter people who murder batteries !"

[james247]

Originally Posted by Jim Woodall

Has anyone investigated replacing the L42 batteries with Lithium? If so, any idea of typical ambient operating temperatures in the engine compartments, particularly in the starboard engine compartment? I've not done very much research but with the house batteries and chargers in the starboard engine compartment an upgrade to Lithium might necessitate moving the batteries and chargers to a cooler location. My understanding is that ambient temperature at or above 45C (113F) is very detrimental to the charging cycle and life of the batteries. I think the engine compartments are well ventilated, but I'm curious if they're well ventilated enough to drop the ambient temperature below 45C (113F). Obviously a few degrees below that threshold would be better.



I've seen recent posts from Impi and Starry Horizons (Out Chasing Stars) about this issue. Starry Horizons' battery bank (and chargers I think) were moved from the engine compartment to a location under a settee in the saloon.



Note sure how accurate this next bit is, but I read that getting the ambient temperature down below 105F puts one in a range in which the charging cycle and battery life will not suffer at all. I'm not sure if it's realistic to get enough ventilation in the L42 starboard engine compartment to even approach 105F.

Try putting a recording thermometer in the compartment and find out what temperature it actually reaches.

[Jim Woodall]

Originally Posted by tuskie

I wouldn't think an engine compartment is an ideal location for a LiFePO4 battery bank. Aside from the temperature issue that you mentioned there's also increased exposure to salt and water. Sometimes its necessary to open the engIne conpartment at sea and it does get seawater splashed in there.

At the very least the batteries would need to be housed in a weatherproof box. With an incorporated battery management system and cell equalizing circuits, a lithium bank is more like a piece of electronic equipment than a bank of old lead acid batteries. The smaller size, absence of gas output and reduced weight would enable installation in a more protected location.

A very good point, I hadn't really thought about the likelihood of seawater being splashed into the engine compartment.

Another response mentioned putting a recording thermometer in the engine compartment to determine temperature and I had thought about that, looking for a reliable one!

[HBrew]

My cat came with factory installed Lithium batteries and they are installed just behind the mast under the seats in the saloon. Centrally positioned for weight, dry and accessible - seems like a good choice to me.

[Valiente]

Originally Posted by HBrew

My cat came with factory installed Lithium batteries and they are installed just behind the mast under the seats in the saloon. Centrally positioned for weight, dry and accessible - seems like a good choice to me.

Factory installed In a Lagoon 42?

[senormechanico]

Right under his moniker it says

Boat: Outremer 51

[SVFairIsle]

If interested, I am selling my 600 AH Sinopoly Lifepo4 setup, including aluminum frame, balancers, compression system, etc. NOS, has not been put through a single cycle. I bolted mine under the galley floor. It would have fit under nav station seat, but running the cables would have been a little tight. Total space is about 20" x 18".