12 volt accesorys on a 24 volt system

[calvnatter]

iv been thinking on adding some extra 12v backup lights and some spot lights to me duce and was wandering how this would work on a 24v system i have 2 12v interstate 1000 marine batterys hooked in searies . could i just hook up my 12v lights to just 1 of them batterys or do i have to get some special system. i think trucks tv on skipe network had some thing for this but i can remember what it was . any help would be nice

 

[212sparky]

I did a build a few months ago. Look at thread title when an electrician gets bored. It they are standard halogen lights you can hook them up in series. + - +- and run them on 24 volts. Easy as pie

 

[ARYankee]

I would say do a search because there are several different ways folks have done it. I would say do what you can afford and what you feel comfortable doing. I am adding a separate 12 volt alternator with battery, just for 12 volt stuff.

 

[gungearz]

There are plenty of threads discussing how to adapt a 12v to a 24v system and even adding a seperate 12v system to your truck. Use the search engine and poke around. It might not have the exact headline but it has been discussed in those threads.

 

[mistaken1]

If your equipment uses the case or frame for the ground/negative connection or has the case or frame bonded to it's negative input and is attached to the vehicle chassis then you must pull 12V from the same battery that has it's negative post connected to the vehicle chassis.

If you do not do this you will have a direct short from the negative post of the 'second' battery to the vehicle chassis/ground.

If your equipment is isolated from the vehicle chassis then you could use the 'second' battery. However, in this scenario, if this equipment has an internal connection from the negative input to it's case and that case is isolated from the vehicle chassis it will work but your multimeter will read 12V from that equipment case to the vehicle chassis.

Water is a good conductor of electricity so when everything gets wet this voltage difference can become dangerous.

 

[Stalwart]

Mistaken is quite correct in his choice of names, he is mistaken on tapping ONE battery for a 12V load. DO NOT do it, it will unbalance the charge on each battery and lead to failure of both batteries. Wait a minute, I don't care, they are your batteies and you have to pay for new ones.

He is correct in tapping the upper battery, unless you like smoke.

 

[3dAngus]

You might want to consider a battery equalizer, where it makes sure both batteries charge up evenly, and also you can tap into it for a 12vdc output that will not hurt either of your batteries when drawing 12vdc power from a 24vdc power source that cosists of two seperate 12vdc batteries in series, like the deuce battery system. I just bought a used one yesterday off a popular auction site for $100 plus shipping, and it will put out 12vdc balanced, at up to 50 amps, plenty enough to power anything I might want to power up in a deuce. I saw where some people were fortunate enought to buy a 100amp output one for the same price, but I could not find those. Made by Vanner.
You might be able to see a schematic for hookup on this picture. Seems easy enough.

 

[rronning84]

You can find most all standard bulbs for any light on ebay in 24V for very cheap.

 

[mistaken1]

Mistaken is quite correct in his choice of names, he is mistaken on tapping ONE battery for a 12V load. DO NOT do it, it will unbalance the charge on each battery and lead to failure of both batteries. Wait a minute, I don't care, they are your batteies and you have to pay for new ones.

True. I was not thinking about balancing the batteries for charging purposes.

This questions seems to come up regularly in the CUCV forum where the imbalance is not an issue (separate alternators).

I just wanted to point out the safety aspects of using the 'second' battery.