Newbie question about solar charging
Every time I think I have somewhat of an idea of what is going on, I seem to get completely puzzled again! We have 1 AGM battery in our trailer. While boondocking in full sun, our 100W solar panel...
Forum Discussion
jornvango wrote:
So it appears to me that the solar is providing 2.8 Amps while the laptop is taking 10.8 A? Or is it taking 3.2 A?
The 3.2a is at "120v" for the input spec of the charger.
The 10.8a is the "12v" output spec of the charger.
The laptop will pull about 60 watts when being used and when "off' but charging, will pull a smaller and tapering amount as it charges up. 60w is about 6 DC amps using inverter and times ten rule.
The 2.8a is what the controller is providing from the solar panel. You have no way to know where the 2.8a is going, as some will be for the battery unless it is all going to your RV "12v" loads
There is no way a controller can tell how full the battery is like 50% or whatever.
The solar (and other chargers like your RV converter) will supply the loads first, and the battery gets what is left over if any. Your laptop when on will be taking it all with your solar set-up. Might be some going to the battery when just recharging the laptop with it off.
To understand what is going on you need a battery monitor that does only battery in and out, and compare that with the solar controller's numbers.
BTW, you "100w" panel will do about 6.2 amps aimed at a high sun, but its "power" (the watts) will be less. If the controller is PWM, the solar's voltage will be battery voltage, and with MPPT, your amps to the battery will be watts out divided by battery voltage, and the watts out will be reduced by the sun heating the panel, line loss, and controller loss. So you never get that "100w".
