P30L overcharging?

Discussion in 'Charge Controllers' started by Radster, Sep 20, 2020.

  1. Hi,
    I just installed the P30L in my van, 100 W panel + 100 Ah 12V battery. With a fully charged battery from shore connection previous, I'm finding that the P30L is running the voltage up on the system. The battery voltage is exceeding 18 volts when connected to the panels and I fear its beginning to boil the battery. When I disconnect the panel from the controller, the system voltage immediately reverts to ~12.6 volts (with mini fridge on). Any ideas why its doing this?
  2. I figured it out. I seem to have assumed the controller to have the ability to flip a switch.
    TomT likes this.
  3. Have you checked the battery, to see if you were boiling the electrolyte? Do you have a Battery temperature sensor? Remember, that the panel will charge the battery, at a charge greater than 12 volts, during the day.
  4. DJS


    I’m concerned this may be happening to me. I have an RV with two new deep cycle Interstate 6 volt batteries in parallel. I have them connected to a P30L and a 100 watt Nature Power solar panel. The P30L shows the batteries at 13.8 volts, but I hear a percolating sound from the second battery in sequence. The water levels are good. The connections are tight.

    I originally installed the P30L temp sensor on the negative post of the second battery in sequence (because my manual recommended post mounting). Tech support told me not to do that; to just attach it to the side of the battery. I’ve done that now but the sensor reads 106 C (same as it had done initially). I’m sure the battery is warm but I doubt it’s 222 Fahrenheit.

    Any recommendations or suggestions? Thank you. I’m new at all this and still trying to figure things out...

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