Solar Panel Connectors
I am a complete newb with solar panels. I just bought a camper that has an older 50 watt solar panel and 20 amp charge controller. The controller itself looks to be a quality unit and I think I will k...
Forum Discussion
Hi,
What BFL13 says is true--for PWM controllers. But it is untrue for MPPT controllers. With them to keep the margin of safty 204 watts is the maximum you can use. I regularly see 17 amps from 256 watts of panels. I have seen 21 amps. My system is MPPT based, with a 30 amp controller.
16 amps is all that the 20 amp controller should be expected to handle. Go over that at your peril. You may let the magic blue smoke out.
One rule of thumb is between 60 and 150 watts of panels per 100 amp-hours of storage. The smaller the battery bank the higher the wattage needed (per 100 amp-hours). Here is a link to the rather special spreadsheet which includes an energy audit, that N8GS has created to help size solar battery charging systems!
Solar Spread Sheet N8GS
For a nice explanation of solar, try this link:
Golden rules of solar
What BFL13 says is true--for PWM controllers. But it is untrue for MPPT controllers. With them to keep the margin of safty 204 watts is the maximum you can use. I regularly see 17 amps from 256 watts of panels. I have seen 21 amps. My system is MPPT based, with a 30 amp controller.
16 amps is all that the 20 amp controller should be expected to handle. Go over that at your peril. You may let the magic blue smoke out.
One rule of thumb is between 60 and 150 watts of panels per 100 amp-hours of storage. The smaller the battery bank the higher the wattage needed (per 100 amp-hours). Here is a link to the rather special spreadsheet which includes an energy audit, that N8GS has created to help size solar battery charging systems!
Solar Spread Sheet N8GS
For a nice explanation of solar, try this link:
Golden rules of solar
