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qtla9111's avatar
Nov 25, 2018

MPPT Charge Controller Troubleshooting

Hi all,

I have the following setup.

230W panel

2 new 6V batteries with new cable terminals

20 amp MPPT charge controller

Xantrex 600W inverter

Solar red light is lit.

Battery green light is flashing.

Load light never comes on.

System chareges during the day, shuts off at night and I need to reset the charge controller.

Xantrex shows the volts so I know power is coming in.

Batteries were changed only because the previous ones were eight years old. I hadn't used the trailer since March so I don't know the previous status except for the fact that it has worked fine for more than 5 years so I can't say that the battery change had anything to do with it.

Why am I not getting a load light if I have interior lights turned on?

Why does the MPPT have to be reset?

The volts go as high as 13.4 during peak sun hours.

I am not an electrician nor do I have a lot of battery experience. I installed the system with the help of friends and it has always worked.

Thanks in advance for your comments.

12 Replies

  • May as well post the controller make and model number.

    What are you resetting on the controller every day?
  • You would normally only have four wires into the controller, omitting the two for Load, which is not needed in an RV.

    Your RV lights etc draw from the battery via the DC fuse panel. the inverter draws directly from the battery in the usual set up.

    So your controller is doing what it should. 13.4 is not very high, but could be a "loaded voltage" if the batteries are being drawn down by any loads at the same time, such as the inverter etc. You would usually set 14.8 on the controller for its high voltage.

    This time of year the sun is so low, and daytime so short, you might not ever see that , but anything you do get is a help.

    You do not need to reset the controller overnight. It will get going again in the morning.

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