Will 12v automotive relays survive 36v?

[oredith]

Originally Posted by timmyjane

Wire the relay to two batteries. Positive to the switch and the ground to the second battery negative. That will give you the 12v you need to activate the relay.

Can someone elaborate on this? I hooked a led harness to the batteries. The harness had a 12v relay. Didn't think much of it. It worked for a bit, but ended up getting fried.

Hoping to be able to just use the harness but in some 12v configuration as stated above, vs rewiring for 36v relays (which are now available on Amazon, but I don't think they'll plug into the 12v relay socket?)

[cgtech]

So, think about it this way- it's a little magnetic coil with wire wrapped around it. They used enough "loops" to make it suitable for 12v. Those "loops" of wire will draw a certain amount of power when 12v is passed through it to pull the contacts closed, (let's use 1 amp as a "made up figure" at 12v). If you "3x" the voltage through it (36v), it will consume 3x the amperage too. The little wires wrapped around the core were "ready to" handle the heat generated when they were handling "1 amp" worth of heat, now they are expected to handle "3 amp" worth of heat (1x voltage = 1x amps = 1x heat), so now its "3x voltage, 3x amperage, & 3x heat). It will die soon. This is the little "pull the switch closed" part, not the power switching contacts portion of the relay.

[JohnnieB]

FWIW: Watts increase exponentially as Amps increase through the same resistance. (W = I² R)

So "3x voltage, 3x amperage, & 3x heat" should read "3x voltage, 3x amperage, & 9x heat"

[cgtech]

Originally Posted by JohnnieB

FWIW: Watts increase exponentially as Amps increase through the same resistance. (W = I² R)

So "3x voltage, 3x amperage, & 3x heat" should read "3x voltage, 3x amperage, & 9x heat"

Indeed it does, It was late & I wasnt thinking.