Agm Battery Space In Forward Engine Cavity

[windomember]

Hi all you 38s5 owners. Mine is in Trinidad and I am in Vancouver, Canada. I am wanting to purchase and take with me 2 Trojan 6v AGM batteries that are 10 3/4" high and 7 1/2" wide and 10 1/4 long and parallel them as my house 400 amp.
I have a Yanmar 3GM30 to be installed and am concerned with clearance for these batteries. One of the benefits of these batteries is that they can be installed at any angle so the critical measurement is the width of the box and the total width of the space. Then the height at any angle to have clearance with the companionway step cover and the engine front.
If anyone has access to these measurements it would be appreciated. Also any comments on the use of these batteries and a recommended charge regulator to go with the Yanmar 55amp alternator. i will also use a Trojan 27 12 volt AGM as starter/reserve which will be installed under the berth on the port side along with a Xantrex charger/inver

 

[Gunni]

Check your electrical calc. You won't end up with the power you think. You will end up with something close to 200AH, not much for a cruiser. And why not source your bats in Trinidad? The airlines will charge you a fortune to fly those things down, and T&T customs will ding you real good.

 

[onecoolair]

Getting Batteries on a Passenger Plane

Check your electrical calc. You won't end up with the power you think. You will end up with something close to 200AH, not much for a cruiser. And why not source your bats in Trinidad? The airlines will charge you a fortune to fly those things down, and T&T customs will ding you real good.

Yes... good luck on that idea.....Instead .....Maybe he is planing on taking a cruise ship to get his batteries there?

 

[windomember]

Actually, you are right about my miscalc on these at 400 ah. I am leaning towards 200 ah on these two in parallel and 200 on another pair installed on the port side of the engine. Going with two banks of 200 ah will give me the 400 ah with a battery combiner when needed. I have calculated led usage and 2.8 ah electric fridge with a 100 watt ( 5 x 20 w rollups) solar array to assist and this should be sufficient for coastal performannce cruising where I will be at a dock 50% of the time with a 40 amp charger connected. The beauty of the AGM's is the ease of installation and no servicing. The charge rate is 5x the wet cells which accords with sailing a performance boat with no long periods of engine use especially in trade wind environs.
Regarding the shipping that will be by ocean freight from Miami (where the batteries will be purchased along with other heavy items) and the supply is to a boat in transit in Trinidad which makes the gear tax exempt. If you have tried to buy reasonably priced marine gear in Trinidad don't bother because it doesn't exist to my knowledge.

My real question was about the space under the ladder in front of the engine. If you chaps have any access to the Beneteau 38s5 you could help but thanks for your comments.

 

[Maine Sail]

Actually, you are right about my miscalc on these at 400 ah. I am leaning towards 200 ah on these two in parallel and 200 on another pair installed on the port side of the engine. Going with two banks of 200 ah will give me the 400 ah with a battery combiner when needed. I have calculated led usage and 2.8 ah electric fridge with a 100 watt ( 5 x 20 w rollups) solar array to assist and this should be sufficient for coastal performannce cruising where I will be at a dock 50% of the time with a 40 amp charger connected. The beauty of the AGM's is the ease of installation and no servicing. The charge rate is 5x the wet cells which accords with sailing a performance boat with no long periods of engine use especially in trade wind environs.
Regarding the shipping that will be by ocean freight from Miami (where the batteries will be purchased along with other heavy items) and the supply is to a boat in transit in Trinidad which makes the gear tax exempt. If you have tried to buy reasonably priced marine gear in Trinidad don't bother because it doesn't exist to my knowledge.

My real question was about the space under the ladder in front of the engine. If you chaps have any access to the Beneteau 38s5 you could help but thanks for your comments.

Please keep in mind that heat KILLS batteries and destroys longevity and AGM's are already one of the least robust battery choices for cruising boats. Most boaters with a 400Ah wet bank don't have the charging capability to even meet what wet cells can take. To take advange of acceptance rates on a 400Ah bank of wets you'd need an alternator of at least 125A and the belsts to drive it. Lifeline wants to see a minimum charge rate of 20% of capacity which is 80A. This is the bare minimum. Odyssey AGM's want a bare minimum of 40% of "C"....

Despite builders installing batteries in engine spaces it is a HORRIBLE location for them. If that is the only choice buy the cheapest flooded batteries you can buy and just replace them when they die..

Also for these batteries they also need to be temp compensated when charging in a hot engine bay or they will be cooked in short order.

 

[Gunni]

Hey Maine, a little off topic, but how heat sensitive are the Li-ion bats that you are working with?

 

[windomember]

Thanks for your input Maine Sail. I have followed some of your other threads and appreciate your insight. This battery compartment is on the main ventilation path to the companionway Dorados. The difficulty with installing other wet cells in another areas is the sulfating under a aft berth that is not well ventilated. This Yanmar 3GM30 alternator is likely a 55 amp so producing about what the Xantrex 40 amp charger will do. The conundrum here may be solved by simply using one set of 6 volt AGMs for 240 amps under the berth even mounted on there sides with the Xantrex inv/chr nearby in a separate compartment and a 12 volt 120 amp in the original battery compartment which will be changed out as necessary. This does away with the sulfate problem which would also not be good for the Xantrex. The boat sits at a dock most often when not out racing/cruising and on a mooring or the hook with controlled minimal power usage other than the 2.8 amp fridge(or ice). The solar array is light and weight is a definite consideration for this boat 's performance.
Any thoughts?