PWM or MPPT?
I just took delivery of a 120W portable solar panel from SolarBlvd, which I will use to charge a single AGM Group 31 with an AH capacity of 105. We have a popup and are minimal electricity users, so I...
Forum Discussion
A 120w panel usually has an Isc around 7.6a, so you can expect that with PWM when it is pointed at the sun, when the sun is high enough on a clear day.
The rule is to have a 20% margin over that in controller size for when you get more than rated amps (happens), so that means another 1.5a for 9.1 so a 10a controller should be ok.
There are dozens of 10 or 20a PWM controllers on ebay for under $20, and some have free shipping. they work just fine as several forum members have reported, including me.
MPPT with a 12v 120w panel will get you maybe another part of an amp above that 7.6. Don't even bother. :)
The rule is to have a 20% margin over that in controller size for when you get more than rated amps (happens), so that means another 1.5a for 9.1 so a 10a controller should be ok.
There are dozens of 10 or 20a PWM controllers on ebay for under $20, and some have free shipping. they work just fine as several forum members have reported, including me.
MPPT with a 12v 120w panel will get you maybe another part of an amp above that 7.6. Don't even bother. :)
