rin67630
Solar Enthusiast
Edit: i have given up with this experiment: it works well, but the tiny buck converters are too sensitive to work outside.
I could achieve performance, but not reliability.
Let us face reality: in the power range 10W to 100W there is no real MPPT SCC, to do the job well.
An expensive Victron might be technically at the top, it needs however 30mA for its own operation and that continuous drag is jeopardizing every benefit of the MPPT operation.
You have a few hundreds of cheap SCCs makes on the market that just pretend to be MPPT.
Buy them, open them and you will just find plain PWM inside, you cannot even find a buck coil for the power conversion in them.
Beside that you have a few better buck conversion chargers, based on CN3767 or BQ24650 chips, that also advertise -even in the manufacturer's data sheet- with MPPT, but do only provide a constant voltage regulation on the primary side. It is better than nothing, but is literally
"Manual Power Point Trimming"
I am using such modules and have provided a networked monitoring for them, and am currently consuming only 15mA including my ESP8266 that does other tasks beside...
I think I could get those modules to work better and perform a real MPPT by software upon injecting a controlled PWM signal mixed into their "MPPT" potentiometer.
But before I begin this development I would like to ask if you know better existing modules in the power range 10W-100W.
My current choice is to build up on that module:
BQ24650 10A Solar Panel Controller
that seems to have a decent 600Khz synchronous buck conversion, flowback protection, and can be adjusted to different chemistries.
I am open to every suggestion, if you know something better.
Regards
I could achieve performance, but not reliability.
Let us face reality: in the power range 10W to 100W there is no real MPPT SCC, to do the job well.
An expensive Victron might be technically at the top, it needs however 30mA for its own operation and that continuous drag is jeopardizing every benefit of the MPPT operation.
You have a few hundreds of cheap SCCs makes on the market that just pretend to be MPPT.
Buy them, open them and you will just find plain PWM inside, you cannot even find a buck coil for the power conversion in them.
Beside that you have a few better buck conversion chargers, based on CN3767 or BQ24650 chips, that also advertise -even in the manufacturer's data sheet- with MPPT, but do only provide a constant voltage regulation on the primary side. It is better than nothing, but is literally
"Manual Power Point Trimming"
I am using such modules and have provided a networked monitoring for them, and am currently consuming only 15mA including my ESP8266 that does other tasks beside...
I think I could get those modules to work better and perform a real MPPT by software upon injecting a controlled PWM signal mixed into their "MPPT" potentiometer.
But before I begin this development I would like to ask if you know better existing modules in the power range 10W-100W.
My current choice is to build up on that module:
BQ24650 10A Solar Panel Controller
that seems to have a decent 600Khz synchronous buck conversion, flowback protection, and can be adjusted to different chemistries.
I am open to every suggestion, if you know something better.
Regards
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