Calling on Solar Techies
I have been thinking of going solar for some time and decided to pull the plug. My wants are a 400 to 500 watt system. I have four 12 volt batteries with 340ah. I am not planning on changing b...
Forum Discussion
time2roll wrote:
"Re: MPPT vs PWM controllers?
MPPT - you only gain it's wattage conversion efficency while it is in BULK mode, once the controller eases off when switching to Absorb, all the ones I know of, revert to PWM mode for absorb and float.
Mike that is the very point that I find is hardest to get across to everyone.And its the very reason you dont get 50% and above gains from them as most people claim.On another similar site a well know poster talked about |the mysteries of MPPTversus PWM" He never ever mentions that fact only give figures to show theory gains.
You are also correct with "all the ones I know of, revert to PWM mode for absorb and floatOt of dozens I regularly test have never found one not to be like that."
https://forum.solar-electric.com/discussion/13231/mppt-vs-pwm-controllers #25
Again - this is really not true. An MPPT controller does not switch to PWM mode in Absorb and Float.
This is super easy to demonstrate if you have an MPPT charge controller. When it is in float and there is still plenty of solar, turn on a load that is around the same as the output you would expect from your solar controller. Watch the panel current and the output current. If output current > panel current (which it will be with series panels) then it is clearly NOT in PWM mode as it is converting 'extra voltage' to extra current.
