question

rpb272 avatar image
rpb272 asked

Battery voltage readings


We have an MPPT 100/30

at night it reports a zero or near zero battery voltage. This cannot be right as we still have power. During the day this reading is 13 to 14 volts.

Any idea what is happening?

MultiPlus Quattro Inverter Charger
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3 Answers
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

The MPPT has no connection to the battery.
Check the wiring and the fuses.

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van-nguyen avatar image van-nguyen commented ·

I got exactly same issue on MPPT 100/10 module.
Replace the fuse and the batter voltage comes back :).
Thanks

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rpb272 avatar image
rpb272 answered ·

Thanks Matthias. I will try to check those things. Where would the fuse be?

also I don’t understand where the reading of 13 volts during the day is coming from?

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Matthias Lange - DE avatar image Matthias Lange - DE ♦ commented ·

I don't know where you have installed the fuse. Normally the fuse should be as close as possible to the battery. Just follow the wires from the MPPT to the battery.

Durning the day the MPPT try to charge the battery and is producing the voltage.

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rpb272 avatar image rpb272 Matthias Lange - DE ♦ commented ·

Thanks Matthias. I have followed the wires and cannot see a fuse. I have tightened the battery connections and unclicked and clicked the cable joins.

Might the MPPT unit be defective? I have tried presets 1 and 2 and reset to defaults but still get the zero readings at night.

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rpb272 avatar image
rpb272 answered ·

Thanks both.

I was thinking that if the batteries are not connected the MPPT should be dead at night-time. From memory I do not think this is the case?


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