Wiring a 12 volt device to a 24 volt system

[PlaynDoc]

Ok, this may sound like a pretty basic question, but here goes....

Situation:
After I get two 12 volt batteries installed - for the 24 volt trolling motor, I want to hard-wire several 12 volt devices to the 24 volt system. For example, I'm going to turn one of the seat bases into a live well, instead of using a cooler - so a hard-wired aerator will be needed. I'm going to install a 12 volt self-priming RV water pump - to fill the live well, and to rinse off stuff. Later, I'll change my stereo to the 24 volt system. I want the power source for my accessories to be the two trolling motor batteries, so the starting motor is dedicated to starting the boat and running my LED navigation lights.

Question:
When I connect the hot and ground wires from these 12 volt devices to the 24 volt power source, how do I do that? Just choose a battery and make the + and - connections? Since the two 12 volt batteries will be connected together, will it 'send too much power' to the device? I'd like to wire each device straight to battery, with use of in-line fuses.

[cwag911]

If you just connect to 1 of the batteries it should be ok. Do you have a voltmeter? If not, they can be had for cheap at Northern tool or an auto parts store. It's always a good tool to have. Here ya go: http://www.amazon.com/DT830B-Digital-Vo ... =voltmeter Very inexpensive but it'll do the job.

[redbeard]

I'm with Carl here. If you pull power from one bat you will get 12 volts, you only get 24 volts when you pull pos from one bat and neg from the other.

[The_Hellbilly]

Pick a battery and wire it up. NOTE: when I wired a stereo system into by 36v golf cart battery pack, it did wear down two (6v) of the batteries signifcantly faster than the others.

[Todd4]

Yeah, that's the only drawback. You don't want to significantly draw down one battery more than the other and then run your 24V TM . You should try to wire up your auxilliary devices to both batteries so they drain "relatively" evenly.

[HandymanHerb]

You can pull from both batteries and still get only 12 volt, you run the wires parallel, you only get 24 volt when you go from positive to negative adding to the voltage, but if you put negative to negative and positive to positive you still only have 12 volts from both batteries.

So you be running series for the 24 volt TM and be running parallel for 12 volts both at the same time