Best 12v to 24v charging set-up for stern thruster

So I bought a Sideshift stern thruster for my 40ft Trawler (runs on 12v and has a generator). I wanted the most thrust so I purchased the 24v unit.

Question:

Since I spend most time off shore power (but do plan on weekend excursions off the grid), whats the best solution for charging the thruster dedicated batteries both on/off shore?

Per manufacturer, they recommend batteries close to the thruster.
Currently, I have 3 large group 4D batteries for Starting and house. The plan is to add another set of batteries dedicated to the stern thruster and somehow charge them. I'm open to suggestions, ideas, and experience.

Here is the wiring schematic from their website.



Thanks,

Josh

Converted my 12 volt bow thruster to 24 volt. Have a 4/0 12 volt power cable to feed the bow thruster and windlass, but no 110 AC easily available there. So I'm going with a 12 volt to 24 volt battery charger. They are on back order till after the first of the year. Currently only available from the manufacture, but significantly cheaper than the 120 volt to 24 volt version. Hopefully worth the wait.

Chargeteck 12 volt to 24 volt battery charger

Ted

Ours are 24v off a 12v system. This
Is the magic box that does it. Not sure who makes as there's no marking, but the thruster is a sidepower.

N4712,

Found the conversion box made by Sidepower...$2000 I'm hoping for more affordable options

Thanks,

Josh

The small outboard fish killers have 12V outboards and 24V trolling motots. Their solution is a 3 batt or 4 batt charger that sees each 12V as a seperiate battery , not part of a bank system. Wire each 12V batt as if it were a stand alone and you are all set..

About $400 at defender 40A

Last winter I replaced my 12v bow thruster with a 24v unit giving me almost twice the thrust with twice the duration. Two AGMs were placed next to the thruster and I removed 30 feet of 4/0 cabling. As for the charging system, I have a Guest 20A (12v)charger capable of two banks. Each bank charges one battery. This was done at a very reputable yard and we had many discussions about it before the install. They do it all the time. It took many discussions because I had to get my head wrapped around it before I could have it done.

No, it's not the most efficient system but it's inexpensive, simple, and it works.

Sterling DC->DC Charger

I have one of these to keep my thruster batteries happy:

Sterling Power DC input 12v to 24v battery charging, battery to battery charger, marine grade DC input charger

Works like a charm.

Steve

Sounds like you have a couple of choices. If you are on shore power or generator all the time a two bank AC charger is the answer. If you are a battery guy a battery to battery charger might suit you better. A series parallel switch would work too but only if you want to use existing batteries.