I have been undecided on the need for a forward battery bank for some time. I will have a windlass (Lofrans Tigres) and possibly a 4HP Vetus bow-thruster installed. I finally decided to bite the bullet and install two group 24 batteries (79AH each, installed in parallel) in the port locker in the vee-berth. I have connected the two banks (house and forward) with 1/0 cable via the Mastervolt DC Distribution 500. This cable is fused at both ends and has a switch at the forward battery end. Most of the time this switch will be off. The forward bank will be maintained by a Xantrex Echo Charger. This will ensure that the forward bank is charged anytime a charging source is charging the House Bank.
My logic is as follows.
1. The windlass needs a battery bank of a minimum of 100 AH - check. Its max draw is 125 Amps.
2. Under normal windlass operations I will switch the connecting switch ON. This will allow the alternator/house bank to pass this amperage to the windlass should it be needed. The 1/0 wire is far in excess of the minimum required for a 30 ft (round trip) of 125 Amps. This setup will permit almost continuous use of the windlass.
The bow-thruster is another ball of chalk;
1. Interestingly it only needs a min battery bank of 108 AH. It draws 350 Amps for a max of 4 mins. In reality you use it far less that this or you are doing something wrong. I would have to connect both banks using 3/0 wire to facilitate recharging from the house bank. This was a non starter.
2. Under normal bow-thruster operations I will have the connecting switch to OFF. The bow-thruster will ONLY operate off the forward bank. This is acceptable in my book. Any current used will be recharged from the Echo Charge once a charging source (e.g. Alternator/solar/wind) is available.
All opinions welcome, speak now or forever hold your peace.