mppt vs pwm

I don't believe that's the case. When in bulk mode, there's no pwm action. The panel should be shorted to the battery.

MrWizard wrote:
Don
Pulse width modulated, means the power is modulated all the time
It's a a high frequency pulse in the dc current, used to stimulate the plates to accept charge and remove sulfation
Doesn't matter wether it's in bulk or float

Hi BFL13,

I was trying to not maximize the difference. 4 is four fifths of five. Hence 20%.

I wish to make it crystal clear that I don't have a "horse in this race". If I do redo my solar currently it is cheaper to go pwm and that is what I would use. If MPPT is cheaper, then THAT is what I will use. Always check the costs.

The issue with the video is not the calculation or the type of pwm controller used, but the methodology of the test and the ensuing conclusion that mppt is 20% (or whatever) better than pwm. Given this particular test, that conclusion is wrong.

jrnymn7 wrote:
Concerning the "20%" question.

It is the difference between the 48 amps, from a 12v series/mppt set-up JiminDenver has seen reported, and the 60 amps he would expect to see from his own 24v parallel/mppt set-up. 48/60 = 80%. Do I have ..............

PT always gets his percentages wrong for some reason. 5 is 25% more than 4, not 20% more. However, 4 is 20% less than 5.

I don't have the original post for 20% between 48 and 60 but 60 is 25% more than 48 and 48 is 20% less than 60

AFAIK, the Shunt controller and the PWM controller do act the same during Bulk. they both let the amps through as though the controller is not even there. The difference is when the battery voltage reaches the set point and they start "controlling"

The Shunt shorts the panel to do on and off so during Absorption, the length of the times on become less as the battery rises in SOC On the Trimetric this can make you dizzy watching both the voltage and the amps go up and down.

The Series (or PWM as is called) does Absorption by holding the voltage and so amps taper. It still fiddles with the amps to keep the voltage up, which you can watch on the Trimetric.

I thought the same thing that MrWizard pointed out regarding the OP video comparing MPPT to an on/off type of controller. I am no expert at all, but I remember when I was researching my PWM controller I read reviews of small cheap ones claiming, "Not truly PWM but just on/off toggling." So how would my Morningstar TS45 PWM behave differently in this sort of bench test?
Product manual Morningstar TS45 PWM

MrWizard wrote:
Did "Consumer Reports" ever do a solar controller or solar panel test ?

That's what we need really. And NOT some agency that gets it's funding or advertising dollar from the products they are testing.

jrnymn7 wrote:
Concerning the "20%" question.

It is the difference between the 48 amps, from a 12v series/mppt set-up JiminDenver has seen reported, and the 60 amps he would expect to see from his own 24v parallel/mppt set-up. 48/60 = 80%. Do I have documentation? No. Is it a fair comparison? I can't say for sure. But Jim has proven to me to be a reliable source of information. And I'm quite convinced he's aware of all the factors that need to be considered when making such a comparison.

Pretty much everyone agrees there are many things to be taken into account. And as to the reliability of what is being reported on the various solar forums, I cannot say. But I also cannot attest to the reliability of much of what is said here on this forum, or by those in the retail industry.

take anything I or others say with a grain of salt. I have some more info such as wiring for the 960w set up but he stopped responding to me as soon as the how and whys the set ups differ. Then again I'm not very popular when discussing solar there because they keep telling me I can't do things and then I go do them anyways. lol

Besides being probably the least technically educated person here, my grains of salt are the extreme altitude, low humidity and the intensity of the sun light here. No where else in the lower 48 will you find that combination of factors. Would my panels loose some at sea level, sure but not that much.

So what I noticed and made a off hand observation is true though. Higher to lower is less efficient than lower to lower. That doesn't mean there isn't a good reason to go higher to lower but rather it is something to be considered.

Don
Pulse width modulated, means the power is modulated all the time
It's a a high frequency pulse in the dc current, used to stimulate the plates to accept charge and remove sulfation
Doesn't matter wether it's in bulk or float
You would need a frequency meter or scope to see it
The avg multimeter will never show it to you
And has nothing in common With shunt controllers, except for being a solar charge controller, they work differently
Shunt controller Do not have PWM

Hint, to insure needing another panel use your inverter more? LOL!

CA Traveler wrote:
Of course I planned correctly and will never want a fourth panel!
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maybe

Did "Consumer Reports" ever do a solar controller or solar panel test ?