Adding a forward bow thruster battery

I'm considering adding a dedicated bow thruster battery and looking for suggestions on forward placement and wiring. Currently the bow thruster is powered by our house bank and easily overheats if overused and just doesn't have much oomph. It's been suggested that a dedicated, forward battery would help with both.

Seems like locating it in the chain locker would work and just using existing wiring with an isolator between house bank of six GRP 31XTs. Would use another 31XT I to keep things simple.

Any tips or pictures of the battery placement would be appreciated.

Lamar,
On my IP-37 I have two group 24 batteries that are located in the aft most V Berth locker. This gives the shortest possible run to the bow thruster motor. I use an echo charger to charge these batteries which keeps the wire size running from the main battery bank manageable. There is a on/off battery selector located in the locker as well. If the weather ever breaks I will try and get you some pictures.

Lamar - have you considered locating it in the compartment with the bow thruster? Or maybe under the forward bunk? I've tried working up in that chain locker and its big but not easy to maneuver in. Just a thought.

Tom

Thanks for replies I hadn't considered with the bow thruster. Do you know how to remove the shower seat to get access? I can't see any screws.

Under berth also a good option, but access to the already installed cables could be more challenging.

Lamar - to get to the screws stick your head in the chain locker and look down. You'll see a round port. Remove that and you have access to the bottom of the seat or lid for the bow thruster compartment. Remove the four nuts and you can lift the lid.

Tom

LJD610 wrote: I'm considering adding a dedicated bow thruster battery and looking for suggestions on forward placement and wiring. Currently the bow thruster is powered by our house bank and easily overheats if overused and just doesn't have much oomph. It's been suggested that a dedicated, forward battery would help with both.

Seems like locating it in the chain locker would work and just using existing wiring with an isolator between house bank of six GRP 31XTs. Would use another 31XT I to keep things simple.

Any tips or pictures of the battery placement would be appreciated.

Having just worked with Mainsail of marine electrics council fame, I feel qualified to comment on the battery charging and maintenance issues you will face. I moved my battery bank a full 40 feet (round trip) of wiring forward to help balance the weight in my IP 31. This main concern is the voltage drop and the error it introduces when your now very remotely located alternator and regulator try to charge your bow thruster power source. But since I do not have a bow thruster I am at a disadvantage when trying to consider your thruster's amperage needs. I first question is, if spending time cruising for a few days involving several uses of your bow thruster without having had a chance to plug into shore power to use the suggested shore charger, how will you keep your new battery charged? Another question is how are you going to wire your battery to the alternator? You're remote battery will get a mere trickle from the alternator. Also you will have to charge the thruster battery as a separate bank. It cannot be tied into the other bank(s) or none of the batteries will get a proper charge due to regulator sensing error. Knowing these things, my approach would be to write down the age and size of your current bank, and measure the round trip to the thruster. With this info I would contact the customer support people for your thruster and see what they recommend. I think it is a matter if increasingly the size of the cables to your thruster, and possibly of your battery bank.