Solar charge controller

Jotun · #1 (**permalink**) 04-13-2007

Can anyone recommend a simple solar charge controller for a small solar panel? The panel I have is for topping off the batteries while not in use. As it is, the panel just has two wires with alligator clips and nothing else. I'm guessing I need some sort of regulator to prevent overcharging, a fuse to prevent shorts, and a diode. The panel is not mounted but just sits in the cockpit. I have two batteries....

Cruisingdad · #2 (**permalink**) 04-13-2007

Jotun,

What is the output of the panels?

- CD

sailingdog · #3 (**permalink**) 04-13-2007

The NC25A is a pretty good, inexpensive charge controller and will handle up to 25Amps.

While not an MPPT-type controller, its also nowhere near as expensive. About $150 USD.

Jotun · #4 (**permalink**) 04-13-2007

CD,
It's on the boat. But it is small. The panel is the equivalent of a trickle charger. I'm guessing the PO just connected it directly to the house battery.

Cruisingdad · #5 (**permalink**) 04-13-2007

SD,

Assuming it is just a trickle, do you even need a charge controller? My guess is no, but I have never direct wired.

- CD

sailingdog · #6 (**permalink**) 04-13-2007

Define trickle charger, and define what the on-board battery banks are made up of... that would help. IIRC, if the power rating of the panel is more than 1/60 the bank capacity, then a charge controller is recommended.

Since the OP hasn't stated the size of the panel or the battery bank, can't really say one way or the other. I prefer not to wire panels directly to the battery.. but would rather set them up on a fuse block and then put a output from the fuse block on a switch...

Jotun · #7 (**permalink**) 04-13-2007

I have two 12v wet-cell batteries on board. But, sitting here at work, I can't tell you the size of the panel. It looks, however, something like those little 1.8 watt panels. I'll bring it home this weekend.

sailingdog · #8 (**permalink**) 04-13-2007

If that's the case, and the batteries are even Group 24s, I doubt it's even keeping them topped off.

And definitely no charge controller needed.

camaraderie · #9 (**permalink**) 04-13-2007

25 watts is less than two amps...no charge controller needed. It cannot really charge your batteries...just keep them topped up when you are off the boat.

kennya · #10 (**permalink**) 04-13-2007

if your charger is 400 miliamps or less you do not need a controler.