Thread: 12/24v hook up?

I was reading you post about the specs for the 80w panel - look under the open circuit bit and you'll see that it's a a lot higher than under load. I'd bet that the 23v you found is the open circuit max for the 100w panel. Put a headlight bulb on it and see what it does under load. I'm betting that it'll drop a fair bit - and that gives you the right input for the regulator.

Originally Posted by discowhite

i got my 100w panel today, sitting in the sun at 9am i have 10.98v and 23.2v depending on where multi meter was placed on the terminals.

now, i have a 12/24v 20amp reg coming so im wondering if its better to hook it up on the 24v side to take advantage of the 6amps max, or dosnt it matter?
the 12v side of the panel has a 5amp max rating...

cheers phil

Well... if it is sitting in the sun with no load, the 10.98V is obviously never going to charge a 12V battery!

run wires from the 23.2 output on the solar panel, neither of my regulators had and option on the input side of it, i guessing you won't either, the output should be straight forward as well which should give you around 13V

Originally Posted by miky

Well... if it is sitting in the sun with no load, the 10.98V is obviously never going to charge a 12V battery!

thanks for the usefull post

cheers phil

Happy to oblige... any time I can help

your incorrect anyway, if im at 10.98v output and the battery is at 9v...what happens

cheers phil

I'm a little lost here - does your panel ( or is it panels ? ) have 2 output cables one for 24 volt and one for 12 volt ? Just curious because none of mine do ... Anyway assuming its on the 12 v side the short-circuit volts should be somewhere near 21 v ... not half of it .. likewise the 24 v side should be up near 40 v ... Shortcircuit amps can be measured directly across the terminals when disconnected from controller and loads .. and they should be about 6.8 Amps and 3.4 Amps respectively .. Most controllers will not put out charge voltage until they are connected to the battery .. and again most controllers will select the input voltage automatically switching between 12 and 24 v .

Cheers

Steve

some older style panels have a center tap. I think but cant verify that its used when your charging a series battery setup.