Using a 18v solar panel on a 12v system
bigslo
Registered Users Posts: 1 ✭
Hello everyone,
I recently bought a hybrid inverter, Luminous NXG 750 which according to their technical specifications (attached image, highlighted in red), supports solar panel of 12v upto 400wp.
A friend of mine gave me four 18v solar panels (atached image) that i wanted to use on the inverter. When sitting in bright sun, i measured around 21-22v, and in shaded areas, i measured around 15-16v per panel.
Is there any easy way to reduce the voltage to a safe level for use in my 12v rated inverter without having to open the front glass pane and rewiring the individual solar cells. Any help would be greatly appreciated.
I recently bought a hybrid inverter, Luminous NXG 750 which according to their technical specifications (attached image, highlighted in red), supports solar panel of 12v upto 400wp.
A friend of mine gave me four 18v solar panels (atached image) that i wanted to use on the inverter. When sitting in bright sun, i measured around 21-22v, and in shaded areas, i measured around 15-16v per panel.
Is there any easy way to reduce the voltage to a safe level for use in my 12v rated inverter without having to open the front glass pane and rewiring the individual solar cells. Any help would be greatly appreciated.
Tagged:
Comments
Using a 400 Watt array (Imp~20-22 amps), you want to charge the battery bank at ~ 5% to 13% rate of charge... 5% is good for weekend/summer/sunny weather cabin. 10%+ is better for full time off grid system (9 months a year or more occupation)...
- 400 watts * 0.77 solar panel+controller derating * 1/14.5 volts charging * 1/0.05 rate of charge = 425 AH @ 12 volt battery bank maximum size for weekend/summer usage
- 400 watts * 0.77 solar panel+controller derating * 1/14.5 volts charging * 1/0.10 rate of charge = 212 AH @ 12 volt battery bank "nominal"/full time off grid
- 400 watts * 0.77 solar panel+controller derating * 1/14.5 volts charging * 1/0.13 rate of charge =163 AH @ 12 volt battery bank "typical minimum" suggested battery capacity
A pair of 6 volt @ ~200 AH "Golf Cart" batteries in series (for 12 volts @ 200 AH) would be a nice bank for this system... If mostly summer use (and/or you use a backup genset for bad/winter weather), 2x strings of these batteries (4x total) in series parallel would give you 12 volts @ ~400 AH.If you want to "reliably" use the 500 Watt output of this Inverter on your battery bank, I would suggest (~250 watts per 100 AH @ 12 volts) a minimum battery bank capacity of:
- 500 Watt inverter * 1/250 Watts per 100 AH (at 12 volts) for flooded cell lead acid batteries = 200 AH @ 12 volt minimum FLA battery bank for this inverter.
Assuming you are in/around Mumbai India, fixed array, 400 Watts:http://www.solarelectricityhandbook.com/solar-irradiance.html
Mumbai
Measured in kWh/m2/day onto a solar panel set at a 71° angle from vertical:Average Solar Insolation figures
(For best year-round performance)
- 400 Watt array * 0.52 off grid system eff * 4.85 hours of sun average (August) = 1,009 Wh per average August day (some days/weeks more, some less depending on the weather patterns at that time).
Lots of guesses and assumptions... Please ask your questions and correct my guesses.-Bill
Note that this inverter requires a battery.
Solar hybrid gasoline generator, 7kw gas, 180 watts of solar, Morningstar 15 amp MPPT, group 31 AGM, 900 watt kisae inverter.
Solar roof top GMC suburban, a normal 3/4 ton suburban with 180 watts of panels on the roof and 10 amp genasun MPPT, 2000w samlex pure sine wave inverter, 12v gast and ARB air compressors.