overcharge problem

fish camp power said:

Im new to this so please be patient We are having a problem with our system, the charge controller is showing over charge and alarming high voltage as soon as the batteries are fully charged.

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Texas-Mark said:

Need more info. What charge controller? What battery voltage?

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sunshine_eggo said:

If you're charging LFP batteries, then they are likely internally imbalanced, i.e., ONE cell is hitting max, and it's cutting the battery out of the charge circuit instantly. The MPPT spikes the voltage because it can't shut itself off fast enough.

The solution for this is to reduce absorption voltage to reduce/eliminate spikes and increase balance time.

In this case, 3.45V/cell absorption and 3.40V/cell float

absorption/float
12V: 13.8/13.6V
24V: 27.6/27.2V
48V: 55.2/54.4V

You'll want to increase your absorption period to 2-4 hours if possible.

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sunshine_eggo said:

If you're charging LFP batteries, then they are likely internally imbalanced, i.e., ONE cell is hitting max, and it's cutting the battery out of the charge circuit instantly. The MPPT spikes the voltage because it can't shut itself off fast enough.

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fish camp power said:

2 renogy 40 a and one renogy 30

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Texas-Mark said:

This is the most likely cause.



What are your settings? Try lowering the charge voltage as shown above.

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fish camp power said:

can the charge controller re set it self to factory settings if the system is off for months

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