48V Input 12V Output Charge Controller

[Tedinski]

Hello all!

I'm brand new to the forums here. I've been reading up (bought a couple solar power books) and I have cobbled together some parts for my system.

I was surprised to find that I'd need some VERY large cable going from my panels to my (unpurchased) charge controller, and down to my battery bank. It's about 40 feet from the panels, through the controller, down to the batteries.

Soo.... I thought maybe I should run my panels in series, giving me nominally 48 volts. This would drop the wire size significantly, and I thought I could run the 48V wire to the charge controller, and then just have maybe 2 feet of large cable to the battery.

BUT I've already bought my deep cycle battery (12 V) and I certainly don't want to buy 3 more right now.

I found a LARGE controller that will accept 48 volt input and put out 12 volts. Sounds perfect, but it's much larger than I need, and is very expensive.

Are there SMALL (15 amp @ 12 volt, so around 4 amp @ 48 volt) charge controllers that do this sort of conversion? 48V in, 12V out?

Could I put a DC to DC converter (48V to 12V) in line after the charge controller, or would that screw up how the controller reads the battery level?

I searched the forum before asking the question.... perhaps I'm not searching properly, or else this sort of hardware hasn't been discussed.

Thanks so much for any help you can provide!

[Naptown]

Take a look at the Morningstar sun saver mppt
This will convert down and give you about 30% more harvest from your panels than a pwm controller will

[Tedinski]

Thanks, Naptown!
I'll take a look...

[Mike90250]

To match high array voltage to battery voltage, MPPT style controllers are used. They are >90% efficient, and have 2 ratings: Max input voltage, and Output amps.

Rogue, Morningstar, Midnight, Xantrex, Steca, Blue Sky and Outback, all make reliable models of varied capacity and input voltages.

Beware of re-badged, un-certified imports that merely have a label saying MPPT.