Portable (suitcase) solar "install" question
I've gone back and forth on solar panels on the roof or portable. Well, due to a tight budget, portable is the only way I'm going to get solar for now and it makes sense for me to try it out 1st as we...
Forum Discussion
ktmrfs wrote:2oldman wrote:johnm1 wrote:Charging efficiency may be improved by connecting panels in series for higher voltage, considering you may be a distance away seeking sun.
My plan would be to move the CC to the storage bay or put it in a water proof plastic box type thing. Either way it'd be closer to the batteries for charging efficiency.
series only provides a benefit if you go for a MPPT controller. with a PWM controller, series connections or 24V panels is a serious drawback. you only get the current that the lowest rated panel can deliver.
The real issue forgotten above-(unusually for this poster) is that a PWM controller that is 12/24 can only do 24 when the batteries are 24--not likely in an RV.
You can't go series (24) with PWM and a 12v battery bank.
With MPPT, where you can do 24/12, in theory you can do better in low light with series and its higher voltage staying above battery voltage than with parallel and its lower voltage. Once the low light voltage in parallel drops below batt voltage -no current; with the higher low light voltage in series still being above batt voltage you get some current.
However, how much current and is it enough to matter? You are in low light! Suppose you can get twice the current in series. But 2 times 1 amp is only 2 amps, which is trivial. That's not going to stop you having to haul out the generator.
Always go for real numbers (if you can get any)---ask, "Twice what?" Eg. Hang onto your wallet at all times! :(
