How to wire swamp cooler to car battery?

[rattlebrain]

I built a swamp cooler using Figjam's wonderful instructions, and it works great connected to 8 AA batteries. Now I want to connect it to a bigger battery, but my first attempts melted the wire!

I bought a West Marine SeaVolt Dual Purpose 685 car battery. It says cranking amps = 685 and amp hours = 65. When I wired it up to my swamp cooler, I used cheap Radio Shack speaker wire (24 gauge copper core) on the battery, with a switch in between the 24 gauge stranded wire coming from swamp cooler. When I switched it on, the fan came on but the wire connected to the battery got hot and melted in about 3 seconds. What a stink! Also scared me! I've been searching around for info on how to do this correctly, but see nothing about what kind of wire to use. Advice, anyone?

[GreyCoyote]

Check for a short first, but that wire at 24 gauge is way too small. Try some 16 gauge or just cannibalize an old 14 gauge extension cord.

[tatonka]

the fan wires and pump wires are very small ga , I have a old small jumper cables to come from the batt , need to connect these with the small pump and fan wire.
do you need a relay ?

[FIGJAM]

That's a little odd.

I just spliced the fan to the pump wire and connected to the battery.

Never got anything hot or even warm.

[tatonka]

That's a little odd.

I just spliced the fan to the pump wire and connected to the battery.

Never got anything hot or even warm.

good , should be no problem then , thks

[Jackass]

Go with at least some 14 gauge, that way you don't get that puff of smoke, like it's part of a magic show or something...

[rattlebrain]

The wires coming from the fan and pump ARE small, which is why I spliced them into more 24 gauge wire. Can I connect that 24 gauge wire to the bigger wire (14 or 16 gauge) coming from the battery?

FIgjam, did you connect the small gauge wire from your pump and fan directly to your battery? I wonder if it makes a difference whether you're using a charging battery or a deep cycle battery?

I like the magic show image for my puff of smoke! Although it was really more like the sizzle of coyote after the roadrunner tricks him into immolating himself ... Either way, something to be avoided.

[FIGJAM]

I just spliced the fan to the pump wire and connect directly to the battery.

Never got anything hot or even warm.