Redarc MPPT + battery charger

cptdondo · February 2019

I found this nice unit that fits everything I need.

https://redarcelectronics.com/products/dual_input_40a_in-vehicle_dc_battery_charger

Except that the MPPT controller is spec'd at 9-32V. I'm struggling to find panels that add up to 600W that are reasonably priced that are within that range. I want to use a couple of these: https://www.solar-electric.com/hanwha-q-peak-g5-duo-320-watt-solar-panel.html but they're spec'd at

Vmp: 33.32 Volts
Voc: 40.13 Volts

Just over the Redarc's limits. Any suggestions on matching panels? Or will the Redarc handle those panels? I've sent an email off to Redarc but no response yet.

Estragon · February 2019

With that voltage range you're pretty much stuck with 12v nominal panels, something like 4-5 of these in parallel:

https://www.solar-electric.com/solartech-spm130p-s-n-130-watt-multicrystalline-solar-module.html

With VOC of 40v, the ones you linked would be way over for the controller. Peak voltage tends to happen in the early morning before the sun warms the panels, so it's Voc that's the limiting factor, not Vmp.

12v panels tend to cost more/watt, but can be used with cheaper pwm controllers. Bigger panels are less $/watt, but tend to need more expensive mppt controllers.

cptdondo · February 2019

Thanks for the explanation. I’m still strugging with mating the pieces parts together. I have an existing 170W Zamp panel but Zamp wants nearly $600 for a second one. I think I’ll stay with the single Zamp panel and then beef up the solar and batteries in the other bank.

BB. · February 2019

As long as the Vmp of your "12 volt" panels are in the range of Vmp~17.5 to ~19 Volts STD (standard test conditions), any "12 volt" panel will work (in parallel).

-Bill

Redarc MPPT + battery charger

Comments

Categories