MEGAWATT 60-AMP INTRODUCTION
To be available starting the last week in January. $110.00
Forum Discussion
Hi Phil,
My apologizes to Mex for going "off topic".
Perhaps I was not clear. The controller needs to be as close to the bank as is humanly possible without being in the same compartment.
Most "12 volt" panels put out 17 volts. The maximum we need is about 14.8 for charging. You would need a whole bunch of wire to get a 2.2 (13%) volt drop. So any wire that can handle the maximum amperage is good enough. With 100 watts that will be no more than about 7 amps.
MPPT swaps volts to amps. So voltage drop is important between the panels and the controller for MPPT to work optimally.
Salvo will tell you I am wrong about the PWM statement. But I am apparently not bright enough to understand why.
I believe MPPT does grab more energy per day. Like it or not, cost is an issue, at least for me. When I did my system panels cost was $5.50 per watt. So MPPT made lots of sense. What I did wrong was to not buy a controller that I could expand only as far as panel wattage. It is frustrating to have room for 2 more panels--and no way to add them without a new bigger capacity controller.
I disagree with portable solar as it means there is little opportunity charging happening. But then, I was a rolling stone and was rarely in the same spot 2 days in a row. Opportunity charging during storage was essential for me.
Some of my other reasons are:
I wish to be able to strike camp quickly when boondocking. i.e. wash, dress, eat, go!
I want charging to start when the sun is up--and cease when it is dark.
I want no theft issues when I am not at the RV.
Storage is already an issue in most RV's. Panels are large, bulky, and fragile.
Easily stored flexible panels are a premium price and to get the maximum benefit from them some sort of frame is going to be needed so you can tilt and twirl easily. They also may deteriorate a lot faster as warranty is typically 50% of traditional panels.
My apologizes to Mex for going "off topic".
Perhaps I was not clear. The controller needs to be as close to the bank as is humanly possible without being in the same compartment.
Most "12 volt" panels put out 17 volts. The maximum we need is about 14.8 for charging. You would need a whole bunch of wire to get a 2.2 (13%) volt drop. So any wire that can handle the maximum amperage is good enough. With 100 watts that will be no more than about 7 amps.
MPPT swaps volts to amps. So voltage drop is important between the panels and the controller for MPPT to work optimally.
Salvo will tell you I am wrong about the PWM statement. But I am apparently not bright enough to understand why.
I believe MPPT does grab more energy per day. Like it or not, cost is an issue, at least for me. When I did my system panels cost was $5.50 per watt. So MPPT made lots of sense. What I did wrong was to not buy a controller that I could expand only as far as panel wattage. It is frustrating to have room for 2 more panels--and no way to add them without a new bigger capacity controller.
I disagree with portable solar as it means there is little opportunity charging happening. But then, I was a rolling stone and was rarely in the same spot 2 days in a row. Opportunity charging during storage was essential for me.
Some of my other reasons are:
I wish to be able to strike camp quickly when boondocking. i.e. wash, dress, eat, go!
I want charging to start when the sun is up--and cease when it is dark.
I want no theft issues when I am not at the RV.
Storage is already an issue in most RV's. Panels are large, bulky, and fragile.
Easily stored flexible panels are a premium price and to get the maximum benefit from them some sort of frame is going to be needed so you can tilt and twirl easily. They also may deteriorate a lot faster as warranty is typically 50% of traditional panels.
