Blue Sky 3024il
I added 520 watts of solar and a Bogart 30 amp system to my rig. It works well but a new problem has happened. It's now common for people to ask how we can have all these lights going and a big tv and...
Forum Discussion
The system may be as good as it gets. You can improve the wiring and get perhaps 0.5 amps more out, but I don't see drastic changes.
My 130W mppt solar outputs about 4.2A now at noon when battery is at 14.0V. Your friend got 470W. Therefore he should get:
I = 4.2A * 470/130 = 15.2A
When discussing mppt charging, it's important to always correlate charging current with battery voltage. The lower the voltage, the greater the current.
The friends solar does have a problem that is not correctable. All 3 panels have different Vmp ranging from 17.4V to 18.3V. For an optimal system they should all be equal. The controller hunts for the maximum power point. His solar has 3 different peak power points separated by valleys. His controller may be locked into a power peak that's not the actual maximum peak. But even if the controller finds the correct peak, the only one of the panels is at the maximum power point.
In other words, in his setup, you can't add all three panels together and say there's 470W. There's 470W only if all Vmp's are equal.
Panels in series don't have that problem. But their performance is actually worse because current through a series string is limited to the smallest panel current producer.
My 130W mppt solar outputs about 4.2A now at noon when battery is at 14.0V. Your friend got 470W. Therefore he should get:
I = 4.2A * 470/130 = 15.2A
When discussing mppt charging, it's important to always correlate charging current with battery voltage. The lower the voltage, the greater the current.
The friends solar does have a problem that is not correctable. All 3 panels have different Vmp ranging from 17.4V to 18.3V. For an optimal system they should all be equal. The controller hunts for the maximum power point. His solar has 3 different peak power points separated by valleys. His controller may be locked into a power peak that's not the actual maximum peak. But even if the controller finds the correct peak, the only one of the panels is at the maximum power point.
In other words, in his setup, you can't add all three panels together and say there's 470W. There's 470W only if all Vmp's are equal.
Panels in series don't have that problem. But their performance is actually worse because current through a series string is limited to the smallest panel current producer.
