2022-11-25

MPPT Charge Controller for Solar Power.

The battery had been charging a bit with a few sunny hours. I did not see a charge current much above 3A with the existing PWM charge controller.

A few days ago I changed the charge controller to a 20A MPPT controller. With decent sunshine the charge current then peaked at about 5A. Definitely an improvement. 

At the moment the system is still not connected to any radio, but the intention is to see if I can run the IC-705 on solar this week end.

Why the 705 and why this week end? The 705 is my go-to radio for running 5W,  it has a relatively low power consumption. I hope that there is sufficient juice from the solar system to run this week end. Further, this week end there is the CQWW CW contest, hopefully with plenty of opportunities to make some CW QSOs with 5W, and make a contribution to the 5W/365 QSOs this year. I still need another 60 to complete my challenge for this year.

If there is insufficient capacity on the battery I can use some other battery that has also been charged with solar power.

The main purpose is to have the vast majority of the 365 QSOs this year run on solar power. I estimate that I have probably done around 50 of them on mains power, so I stand at around 90% solar right now.

With the planned improvements I expect to run the 705 fully on solar power all year, and some of the other radios most of the year. 

The other test with the MPPT controller was to detect RFI/noise from the controller. As it is right now I have not noticed any noise, but the controller has not run full charge current yet. 

I do expect, however, that with a bit of filtering I can run this MPPT controller without creating a noticeable amount of RFI on the HF bands. More testes will be needed.


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