Any solar panel peeps on here?
 

Have had alittle solar setup on my greenhouse.

Equipment -

4- 120mm commerical computer fans. So they push more volts then household pc.

2 - 1.5 12volt solar panels

Thermostat

Old 12v car battery

Everything was working fine but forgot to remove the leads to the battery while working on the thermostat connection. So the fans ran for 16hrs or more and drained the battery since there was no light to power solar panels. Charged the battery here and its good. Alittle weak to start a car maybe but should be fine with my setup and the thermo will shut the fans off. Thing is that at night with all the connections still on the battery will it drain it? I would think not just like the battery being still in the car.

Second - If this battery is toast can I use a electric battery thats 12v thats made for a tractor. Do I need a solar charge controller with this setup? Fans turn on when its about 80* in the greenhouse then go off when it gets below.

Thanks for any help!