LED Pod Lights - 12V in Series Question

[Lee0smond]

I bought 4 identical 18W 12V LED Pod lights. My cart has (6) 8V batteries so no real way to get 12V without a step down.

Can I wire the Pod lights in series (since they are identical) and then hook the 4 12V lights up to the full 48v bank?

They're only 18W so
18W/12V = 1.5A
1.5A * 4 Lights = 6A
6A * 1.25 safety factor = 7.5A

So with only a 7.5 Amp max draw, I'm not too concerned with overloading a simple switch and wire.

[Volt_Ampere]

Maybe is the answer. IT depends if the voltage splits evenly among them. If you run them in series, they will only draw 1.5 amps from your batteries! Try hooking them in series and measure the voltage across each one. If it's close to even then you're good. My guess is that it will work fine. All of your wires will only see 1.5 amps if you run the lights in series!!!

[Lee0smond]

Originally Posted by Volt_Ampere

Maybe is the answer. IT depends if the voltage splits evenly among them. If you run them in series, they will only draw 1.5 amps from your batteries! Try hooking them in series and measure the voltage across each one. If it's close to even then you're good. My guess is that it will work fine. All of your wires will only see 1.5 amps if you run the lights in series!!!

Good call on the Amps. Not used to running lights in series so brain fart on that one.

Ok, so yeah at 1.5A even less of a risk of overloading wire/switch. Probably won't even need a relay for that low draw and just put an inline fuse before the rocker switch.

So in theory this works. But just confirm lights seeing similar voltage. Just as a worst case, is the risk that I burn out one light prematurely if the voltage is out of whack?

[Volt_Ampere]

Yes. Each pod is actually going to be several LED's in series with a dropping resistor. As long as you see equal voltages (or nearly so) across each one, you should be good. Keep in mind that if one fails, they will all go out. With that light a load, you could also get a fairly cheap voltage reducer to run them in parallel.

[Lee0smond]

Originally Posted by Volt_Ampere

Yes. Each pod is actually going to be several LED's in series with a dropping resistor. As long as you see equal voltages (or nearly so) across each one, you should be good. Keep in mind that if one fails, they will all go out. With that light a load, you could also get a fairly cheap voltage reducer to run them in parallel.

They were $28 for 4, so I'm not super concerned if they burn out haha just wanted to confirm I wasn't doing something ridiculous to burn down the cart haha

I'll take a look at voltage reducers.

So would it go:

Bat+ -> Fuse -> Reducer -> Switch -> Lights in parallel

Also, since 48V is the rating but obviously not peak voltage, do I need to size the reducer for a 72v system instead of a 48V rating?

[Volt_Ampere]

A regular 48V reducer will work fine. Many reducers come with an inline fuse in the bat plus lead. You can also add one in the 12V output lead. Wiring the reducer varies depending on what you get. I prefer the ones that have a trigger wire that goes to the ignition switch to turn it on. It hooks across the battery directly. Then you would switch the 12V to the lights and the reducer would only power on when the ignition switch is on. If you get one without a trigger wire, then you would want to switch the battery power to the reducer so that it isn't on all the time.

But your idea to put the four in series will probably work just fine and if that's the only thing you want to run then you don't need a reducer.

[Lee0smond]

Originally Posted by Volt_Ampere

...
But your idea to put the four in series will probably work just fine and if that's the only thing you want to run then you don't need a reducer.

Another quick question, this is getting a little too cobbled for my liking, but are there any risks to temporarily running an oversized AC rated switch?

Got a cheap 250V-10A/125V-15A rated switch. Going on the 48V cart with an amp draw of about 1.6.

Will this work as a temporary solution? or not a good idea?

[Lee0smond]

Looking at amazon F/R switches, they also seem to be rated with AC only, so I can't be crazy thinking the that AC switch will hold for 4 lights, am I?

[Volt_Ampere]

Switches don't really care AC vs DC unless there is a very substantial load on them. Your four lights won't push any normal switch especially one rated for 15 amps.

[Lee0smond]

Originally Posted by Volt_Ampere

Switches don't really care AC vs DC unless there is a very substantial load on them. Your four lights won't push any normal switch especially one rated for 15 amps.

Thanks again buddy, appreciate your answers!