question

ako avatar image
ako asked

Effect on MPPT OF NO Battery Connected

Knowing that MPPTs require the batteries to be connected before the Panels and Visa Versa on removal i am concerned about the effect on it should the batteries be disconnected while the MPPT is still receiving input from the panels . A faulty Fuse or Breaker triping could easy bring about such a situation .

MPPT SmartSolar
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2 Answers
Alexandra avatar image
Alexandra answered ·

@AKO

For the most part, if the energy has somewhere to go nothing.

Sometimes if there is a sudden removal of load at full production, there will be an overshoot of production. You will see the max recorded voltage musch higher than set for charging. Obviously you don't want that to be outside of operating max voltages.

Batteries disconnecting (BMS contacts opening) happen alot more than you think on systems.

So far I have not seen ill effects from it happening. I would say though if it is a repeat problem, best to deal with the root cause.

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ako avatar image
ako answered ·

Thanks Alexandra , i have normaly have a charging voltage of 115 volts on an 150 volt MPPT although the panels are only suposed to give a maximum of 105 violts but there is still an allowance .Ii did have a 100 amp Breaker trip at 40 amps and the only problem that time was we got home to battteries that hadnt charged so needed to run the generator that night . The breakers been replaced with fuses , the line in as been split and each runs through100 amp fuses , the idea is that if there was a problem that would cause the fuse to blow then both would but if it was a faulty fuse then there is another protecting the circuit , if i had used 2 breakers that way then no harm would have been done , I was concerned that next time i might not be so lucky and it could be expensive if the MPPT couldnt deal with it .

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