Batteries / Bow thruster question.
I have a 2600 SE that currently has 2 x 85 AH deep cycle batteries connected to a 1/2/Both switch. They are just over a year old.
I start the engine on 1, switch to 2 on the anchor then 1 to start again at the end of the day. Both charged on shore power when back at the marina.
When using the bow thruster (needed for a difficult home berth) , the voltage drops quite significantly,
even on the both switch and the other day cut out the nav device.
I'm thinking of adding a third battery and this is my plan...... parallel the 2 x 85 AH deep cycle batteries and use as the house bank (Switch position 2), buy and fit a proper starting battery with some serious CCA to use for starting and also to help deliver some decent power to the bow thruster as I don't think the deep cycle batteries can deliver the power in quick short bursts.
I figure this is the easiest and cheapest way to do it, thoughts??
(The current 85 ah batteries have been tested, all good, alternator is delivering decent charge as is the shore power battery charger)
I don't really want to add dedicated batteries up front for the bow thruster due to expense/ complexity and it really is only used for 2 - 3 short bursts.