Solar install on a Trailer, newbie questions
Hi, I just got a solar panel and controller for my TT. I want to install the panel on the roof laying flat but am unsure of how to attach it. Q#1 Should I run some screws or bolts into the roof an...
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My point is vd between the panel and controller means the panel operates at a higher voltage so there is less current and it can enter into the area where current drops like a rock with increased voltage drop. Isc is greater than Imp which is much greater that I at voltages above Vmp. Heat reduces Vmp, therefore it is easier and easier to get the panel to operate above Vmp (region of rock slide current) when it is hot and there is vd. Maybe you do recommend 22awg!
Batt never gets to abs unless SUN does the taper cuz vd is based on panel current even in tiny doses and panel current does not taper, the controller sees a higher voltage than what is at the battery. Thus the reason you suggest a voltage sensor, without it the batt v is less than the controller v due to vd when current is flowing at whatever rate the panel makes it and not some reduced acceptance rate. With the sensor the panel operates at a higher voltage which means less current.
vd is based on current when it is flowing. I run my pump for 30 mins a hr, the pipe friction is based on when the pump is running not 1/2 the pump rate.
It is 25C here today and my panel is 60C where on the IV curve does the current crater at these conditions?
to be absurd let's say vd at some pt is 2v and the controller sees 14.6v and the battery is @ 12.6v. vd stays @ 2v since the current is in busts of full power, the width (time) of the pulse (current) changes. Batt acceptance has declined to nil but every time the controller is ON the full panel current for some fraction of a second blast at the battery with 2v of drop. With each pulse, 2v @ whatever A is made into heat in the wire.
PWM limits current by making the pulses of power shorter and the non power time longer at some Hz. Over a time frame the current can be less than the panel but the pulses are full strength with full strength vd based on the full strength current.
Batt never gets to abs unless SUN does the taper cuz vd is based on panel current even in tiny doses and panel current does not taper, the controller sees a higher voltage than what is at the battery. Thus the reason you suggest a voltage sensor, without it the batt v is less than the controller v due to vd when current is flowing at whatever rate the panel makes it and not some reduced acceptance rate. With the sensor the panel operates at a higher voltage which means less current.
vd is based on current when it is flowing. I run my pump for 30 mins a hr, the pipe friction is based on when the pump is running not 1/2 the pump rate.
It is 25C here today and my panel is 60C where on the IV curve does the current crater at these conditions?
to be absurd let's say vd at some pt is 2v and the controller sees 14.6v and the battery is @ 12.6v. vd stays @ 2v since the current is in busts of full power, the width (time) of the pulse (current) changes. Batt acceptance has declined to nil but every time the controller is ON the full panel current for some fraction of a second blast at the battery with 2v of drop. With each pulse, 2v @ whatever A is made into heat in the wire.
mike-s wrote:
PWM limits the voltage, and indirectly the current. Not the instantaneous current, which you seem fixated on, but the actual charge current - how fast coulombs flow into the battery.
PWM limits current by making the pulses of power shorter and the non power time longer at some Hz. Over a time frame the current can be less than the panel but the pulses are full strength with full strength vd based on the full strength current.
