Newbie to solar question
I am thinking about building a some what protable solar recharge kit for my tt so I can do up to a week of boon docking. I know I need to do the total power worksheets. What I was wondeing is more o...
Forum Discussion
jhilley wrote:
There are any number of good reasons to use PWM controllers with higher voltage panels - smaller cable, longer cable runs, lower cost, bigger panels for limited roof space, lower cost per watt panels
That is a very big misconception. A PWM controller does nothing but directly connect and disconnect the panel to the battery to control amps flow based on battery voltage (a morningstar controller does this 300 times/sec). A PWM does not do any modification to the voltage or current from the panel. So when the controller has the panel connected to the battery the panel is operating at battery voltage. If you look at the operating curve of a panel you will find you are at 50% or less of panel output (in watts) doing this. While it will work you loose at least 50% of the panel capability and are still transmitting DC current at battery voltage so not improving line loses.
Statement sounds good but PWM controllers and Solar Panel operating curves do operate such to make it true.
