By using the environmental sensor capabilities to monitor the battery heater I was able to extract some interesting data showing how the concept works.
This picture is of one 24 hour period showing the -21F temps incurred over night.?
Note how quickly the battery warms up when the sun rises. The "comb" looking portion is the thermal switch turning off and on alternating between charging and warming the battery.
This circuit keeps the battery between 20-30 degrees F when the sun is out.
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Here is a screen grab for 3 days, each night well below zero and when the sun rises the system goes to work first warming then charging the battery.
I have some thermal switches with a 10F higher range I plan to try when they get here. All in all, I am pleased with it's performance.
As an aside, I'm hearing a bunch of new "meshers" up Regal and Paynesville way.? I'll try to get to know them.
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73
Mike N0QBH
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N0QBH Mike Berg