Cheap MPPT regulator from China - true and not fake?

[kje]

I wanna buy a cheap MPPT regulator from China, but how do I know if it is a true MPPT regulator and not a fake one?

[russ]

I wanna buy a cheap MPPT regulator from China, but how do I know if it is a true MPPT regulator and not a fake one?

So you want to buy something that does not exist?

[kje]

Is there any truth in this video?

https://www.youtube.com/watch?v=6q2ICp7acvA

[Mike90250]

Is there any truth in this video?
https://www.youtube.com/watch?v=6q2ICp7acvA

It is truly a video

[Mike90250]

I wanna buy a cheap MPPT regulator from China, but how do I know if it is a true MPPT regulator and not a fake one?

You buy it, and test it yourself. 250 watts in, 90 watts out= PWM. 200w out= MPPT

But read the comments of the poster, it's got bugs, does not sleep, and consumes power at idle

[sdold]

Aren't they power in = power out?

[yewsuck]

The only way to be sure is to check them with meters in and out. Here are two videos that show a fake one. Part 1 and Part 2. He kinda confirms what is said in the video posted above and shows you how to do a some test to see if it is real or not. I will just say the US based companies offer something that is designed to be stable and not burn your house down. Abroad products may have skimped on a few hidden things like the Amp capacity of the terminal board. Just a thought. YMWV on things from abroad. Most of the guys here rely on there components not to fail for power and safety. It is common for most to also say that at Lower voltages and Amps, that it is just not worth the extra cost for MPPT or the cost of finding a REAL cheap MPPT. Most of the time they feel they can get more panel for the price difference and be ahead.


MPPT-M20 Solar Charge Controller #2 - A Devious Fraud
Part 1

https://www.youtube.com/watch?v=KA3X8XLxWHU

Part 2

https://www.youtube.com/watch?v=la-gvy0DfJs

Most of these Abroad controllers have not been thoroughly tested on the long term so there is not an answer. Most just spend there money on known real products found in the USA and never look back.
-YS

[yewsuck]

Aren't they power in = power out?

Yes they are and should be if real. Minus Conversion Efficiency and the power to run the Controller. The internal electronics take power to work. Hence why the above poster said 250w in 200w out is MPPT.

-YS

[Mike90250]

Aren't they power in = power out?

Nope. internal losses. Best are 95% efficient. This one in the video has a sizable heat sink, and I expect it's not any better than 90%, if even that.

[sdold]

Nope. internal losses. Best are 95% efficient. This one in the video has a sizable heat sink, and I expect it's not any better than 90%, if even that.

I meant that I think the PWM controller power output is (about) the same as the input.

Edit: Disregard, I may have misunderstood your post, I think you were talking about panel STC power, not the controller input power.

[inetdog]

I meant that I think the PWM controller power output is (about) the same as the input.

Edit: Disregard, I may have misunderstood your post, I think you were talking about panel STC power, not the controller input power.

PWM means current out = current in (minus a small amount to run the electronics). Very simple.
And that generally means power out from the panel is less than Pmax, getting worse as the panel voltage (Vmp) increases above the battery bank voltage.

[sdold]

PWM means current out = current in (minus a small amount to run the electronics). Very simple.
And that generally means power out from the panel is less than Pmax, getting worse as the panel voltage (Vmp) increases above the battery bank voltage.

The PWM controllers I'm familiar with only have a half volt drop or so across the switching device. The panel is pulled down to the battery voltage. P=IE, so the input power is the same as the output power, minus a small loss across the switch (0.3v for the Trace C series for example).

[inetdog]

How could a panel increase above battery voltage with PWM? The PWM controllers I'm familiar with only have a half volt drop or so across the switching device. The panel is pulled down to the battery voltage. P=IE, so the input power is the same as the output power, minus a small loss across the switch (0.3v for the Trace C series for example).

What I said and meant was when the Vmp of the panel is higher than the battery voltage power will be lost. For a given current the panel will have a corresponding output voltage. To get the rated power from the panel (under mythical STC conditions) you have to have the current and the voltage at Vmp and Imp at the same time.
A PWM controller will draw more current than Imp, dropping the voltage below Vmp and costing you energy.

[sdold]

What I said and meant was when the Vmp of the panel is higher than the battery voltage power will be lost..

I realized that, but you caught me before I was able to edit my point was only that power in and out of the controller is virtually the same. The power lost by using PWM isn't lost in the controller, it was never there to begin with because the panel wasn't allowed to develop it.

[inetdog]

I realized that, but you caught me before I was able to edit my point was only that power in and out of the controller is virtually the same. The power lost by using PWM isn't lost in the controller, it was never there to begin with because the panel wasn't allowed to develop it.

True. It is nevertheless lost as a result of using the PWM controller. So we could say that it is lost by the PWM controller even if not lost in the PWM controller.