series parallel switch for 12v/24v charging

[jfelds]

Hi Guys:

I have a 12v boat with a 24v thruster which is powered by 2x 12v batteries wired in series. It has a dedicated charger which functions when the the boat is connected to shore power or the gen set is running. I would like these batteries to be charged by my 200 amp alternator that charges all the other batteries on board so that I don't have to run the gen set just to charge the thruster batteries. Besides, how do I know how long to run the genny just to charge these batteries?

I've been told that I could rig a series/parallel switch to accomplish this. Does anyone have experience with this? Thanks.

Jim Felds
MV Kokomo
48 Hatteras LRC

 

[oscar]

Not familiar with a specific product for this, but the theory is sound. Put a disconnect in the cable that runs from the first to the second battery. What you have now is two twelve volt batteries, period.

Now you can run a two bank 12V charger.

The only question I haven't answered in my head yet is whether you would have to make sure you disconnect the charger from the two batteries BEFORE you switch back to the 24V configuration.....

 

[Roamer Blue]

The trucking industry used 12/24 series/parallel switches back in the day.

Try a Kenworth dealer, look for an old guy in the parts dept...

An excellent strategy for your install, all the 12 volt things stay connected, as they are unable to get 24 volts to them, regardless of the series/parellel switch position.

RB

 

[boatpoker]

The trucking industry used 12/24 series/parallel switches back in the day.

Try a Kenworth dealer, look for an old guy in the parts dept...

An excellent strategy for your install, all the 12 volt things stay connected, as they are unable to get 24 volts to them, regardless of the series/parellel switch position.

RB

+1
Did this 20 years ago on my boat. Bought a series/parallel switch from a farm equipment place (lots of farm equipment works this way) and a small relay. ...... simple wiring.

 

[awpptdt]

Same setup, I installed a series/parallel switch for my bow thruster. Got it off of ebay, made by Texas Industrial Electric, works great. The only draw back is it is rated for only a few minutes use at a time just like the bow thruster, so I wired it to a momentary push button switch which I mounted next to the thruster control in order to operate it and the thruster with one hand, fly bridge also. The unit has a built in circuit that you can hook up that will charge your batteries with 12 volts. I can not tell you the model until I visit the boat latter this week. You can call them at 210-654-4075. Very friendly and helpful, I think it was around 200 bucks. Go to there web site to see excellent wiring diagrams.

 

[O C Diver]

Do you have an inverter on your boat? Connect the battery charger to the inverter. My boat has a 2,800 watt inverter with a transfer switch. When I leave the dock, there are several circuits that are powered by the inverter. The bow thruster battery charger is on one of them. When I turn on the generator or connect to shore power, the transfer switch moves the load to one of them. Seems a lot simpler and the batteries are being recharged with power from the engine alternator.

Ted

 

[kev_rm]

Kinda complicated for something that is working? Maybe I'm just jealous you have bow thrusters.