12v spot lights wired in series?

[snoredog]

hey guys I have been trying to figure something out and the search didnt yield very much info on this. my dad uses our deuce for a hayride every year for all the kids from church and he asked me if there was any way I could get some more lights on it. most of the ride is down a curvy firebreak in the woods so he needs to be able to see well. I just so happen to have (4) 130 watt spotlights and (2) 100 watt spotlights i pulled off my old truck that still work, 12v of course. my ? is if I can wire 2 of the 130 watters in series and safely run off the 24v circuit of the truck? I know if 1 burns out then they both go but they are not the primary headlights so that is not really an issue. also I have a pile of those metal toggle switches with the red safety covers I bought off ebay a while back that are rated @ 20A. on my old truck I had to run relays for the 12v set up but with the 24v and reduced amp draw can I run the whole draw through the switch?

also, lets say I decided to run all (4) 130 watters, (2) 100 watters, and (2) 55 watt work lights on the back. if my math is right total draw is 830 watts @ 24v would be about 36 amps right? will the stock alternator on the deuce supply that much or do I need to cut back the load some?

sorry for the long post but I dont want to mess with something not knowing everything about it first

thanks - John

 

[Stalwart]

Yes you can do it, the switch might not last too long and may get warm or even hot. Nominally with your engine running, the switch will flowing just under 30A. If you keep the revs up your stock 60A alternator should keep up, but even if not, you will be loosing a little bit and have a draw on your batteries. If you start with fully charged batteries, unless you are going to be running for hours on end, the batteries just won't be fully charged when you're done.

 

[OPCOM]

You can use a 50, 70, or 100 amp DC circuit breaker as your switch, and run leads from this 'power distribution area' to the battery, both + and -, with 6-ga wire. then you can draw what you like. You can use a large terminal strip for the high current wires. I have seen similar work done using 12 ga. romex house wire, using all 3 conductors as one combined. Cheaper than #6. You can use #8 but use only a 50A or 70A breaker if using less than #6 wire. The breaker will pop in case of a short, and will last a long time as a switch. The only thing might be that all the lights coming on at once will draw a surge that can pop the breaker, so that is why use a bigger size. If you have nothing else, an AC-type house breaker will also work.

The breaker sizes mentioned are suggested to act in place of a fuse. Breakers do not limit the current, only the load does.

 

[snoredog]

thanks for the help and I just realized I need to correct myself. when I referred to those switches powering everything I meant a pair of lights on each switch, like 2 130s, 2 130s and 2 100s each on seperate switches. or would a standard 12v 40A relay or two work with 24V? cause I have 10 of them in a box with nothing to use them on at the moment. so the 12V lights should not be a problem set up in series right?

 

[goldneagle]

The series idea will work. I am not sure the 12 volt relay will. You can get 24 volt relays at a truck parts store. NAPA may have it. I just bought a 30 amp switch to run my aux. fuel pump-so you a=can try using multiple switches to run the paired lights.

 

[Speddmon]

the 12 volt relays will work also, as long as you put the coils in series just like you are wanting to do with the lights. But the same thing will happen...if one relay coil goes bad....they both stop working.

 

[Scarecrow1]

To be safe I would use the inverters sold to down size the voltage to the proper output . There is one on Ebay for 50 Dollars and no there not mine or anyone I know

 

[Memphisdoug]

. on my old truck I had to run relays for the 12v set up but with the 24v and reduced amp draw can I run the whole draw through the switch?

Your amperage is actually going to be the same in this case with 24V because you have the two lights in series. Voltage = Amps x Resistance. Since both your voltage and resistance are doubling the amps will remain the same. So, if you needed relays before for the switches you still will.