I've got a new EPEver 3210AN, 30 A MPPT solar charge controller, and single 320 W 40 V solar panel connected about 4 feet (1 meter) away with 12 AWG wire. It's a very simple van setup. My battery is a single 12 V, 115 Ah deep cycle battery.

(The oversized panel is basically to allow use of fans, TV and charging during daylight hours, and also to get more power on cloudy days and in shade -- not so much for charging a battery up.)

In morning cloudy skies in Florida in October at 10am I was reading:

  • PV in: 30 V, 6.5 A, 0.6 kWh
  • Battery: 13 V

How many watts is my solar panel producing at the above reading? Is it (6.5 A x 30 V = 195 W) or (6.5 A x 13 V = 84.5 W)? How is 0.6 kWh (600 Wh) possible or true?


Which voltage?

The "maximum power point" of the Maximum Power Point Tracking (MPPT) charger is a specific point in the voltage vs current curve of the solar array. From the manual you linked:

Maximum Power Point Curve

The input voltage (from the array) will vary based on which point on the V-I curve the charger is operating at. In contrast, the output voltage will be a function of the battery, and will stay essentially constant while the battery is charging. So we can assume that the current you're reading on the display is current draws from the panel.

Power produced is 30 V x 6.5 A = 195 W.

What does the energy reading mean?

Page 16 of the manual includes this section;

Clear the generated energy


Step 1: Press the “ENTER” button and hold 5s under the PV power interface and the value is flashing.

Step 2: Press the “ENTER” button to clear the generated energy.

This makes it seem that the kWh reading on the display is just an accumulated value since the charger was first connected, or since this energy clearing operation was performed.

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