Bowthruster Wiring & Charging

[Dino]

Hi,
I'm in the process of repairing my Cramm 12V bowthruster. The solenoid was in bad shape and one of the retaining clips for the motor brushes was damaged. It also needed a new time delay unit as it was corroded.
The bowthruster was supplied from one of the 12v batteries in a 24V bank for engine starting. I have disconnected this and have a new plan.
I have bought one of these https://www.es-store.co.uk/product_...=Victron-Non-Isolated-&cat_id=93&show_menu=26
The plan is to connect one 24V engine bank to the DC-DC converter/charger. Then connect the 12V side to a new bowthruster battery in the bow. This battery will feed the bowthruster and I will fit an isolator switch also.
Has anyone used this type of buffer charging to charge a bowthruster battery. It seems to be a simpler option than fitting a 12V alternator to one engine.
What size cable would I need to run from the 24V bank to the DC-DC charger?

 

[matt_lake]

Hi,
I'm in the process of repairing my Cramm 12V bowthruster. The solenoid was in bad shape and one of the retaining clips for the motor brushes was damaged. It also needed a new time delay unit as it was corroded.
The bowthruster was supplied from one of the 12v batteries in a 24V bank for engine starting. I have disconnected this and have a new plan.
I have bought one of these https://www.es-store.co.uk/product_...=Victron-Non-Isolated-&cat_id=93&show_menu=26
The plan is to connect one 24V engine bank to the DC-DC converter/charger. Then connect the 12V side to a new bowthruster battery in the bow. This battery will feed the bowthruster and I will fit an isolator switch also.
Has anyone used this type of buffer charging to charge a bowthruster battery. It seems to be a simpler option than fitting a 12V alternator to one engine.
What size cable would I need to run from the 24V bank to the DC-DC charger?

How far is it from the DC/DC charger to the location of the bow thruster battery?

 

[Dino]

About 5-6 metres.
I have done a bit of research on this today and I think I may have an issue. It appears that the unit I have bought will continuously charge the bowthruster battery. A remote on/off switch can be wired in from the ignition switch but that does not seem ideal either. So I think I need to wire in a VSR or similar that will only cut in when the bowthruster batter needs a charge and switches off when it is fully charged.