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joomies avatar image
joomies asked

MultiPlus low battery shutdown even whit OK volts.


Hi

Our MultiPlus 12/3000/120-16 will shutdown at 13.10V. Same time low battery warning will come up. This happened regardless of power usage at that time.

Configuration value for shutdown is 11.50V and restart value is 13.10V. Pre-alarm value is 11.65V.

What is wrong?


MultiPlus Quattro Inverter Charger
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3 Answers
michelg avatar image
michelg answered ·

Hi Joomies, how much Amps is the Quattro sucking from the battery when the incident happens ? It can be several things : the cable is too thin, so when the VDC is measured at the entry of the Quattro, it has lost too much Volts in order to be usable. Or, the battery is unable to provide the needed Amps during the time needed, either because it is discharged/sulfated, undersized, or damaged. Details of your battery are needed in order to understand better what is happening.

Michel

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joomies avatar image joomies commented ·

Thank you Michel.

We have 400Ah lifepo4 battery. 70mm² cable from battery to busbar and 2 X 50mm² from there to MultiPlus.

Shutdown happens no matter how much amps is drawn from battery. This has happened on 100A draw and 3A as well.

If battery voltage is under 13.10V, MultiPlus will show low battery warning and won't start at all.

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alan avatar image
alan answered ·

Have you connected the Aux battery sense?

It sounds like you have a high resistance joint on the main battery cable under load.

Have you measured the voltage on the input terminals?

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nhenderson avatar image
nhenderson answered ·

Having a similar problem. System is CCGX, Multi-II 48/5000, BMV-712, two strings of four 200Ah Gel batteries (6 m old). ESS Mode, "keep batteries charged". CCGX relay is used to start the generator and at night, the thresholds are 60% SOC or 45V for 5 sec. The Multi-Inverter is set for DC input low shut-down 40V, DC input low restart 46V, pre-alarm 44V. SOC low shutdown 50%, restart 70%.

At 3:30 AM the voltage fell to around 46V (as per the alarm sent to the CCGX), and the inverter shut down with a low battery light. Then maybe 30 sec later as the voltage rose again it restarted. And a short time later shut down again, cycling until I started the generator manually. The CCGX didn't start the generator of course because its threshold wasn't reached.

Is this a bug? Why would the Multi shut down so much above the threshold? Is it calculating some other threshold for some reason? Behavior was the same with the default low shut-down of 37.2V.

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seb71 avatar image seb71 commented ·

When using ESS, the voltage thresholds are those set in the ESS assistant.

The voltage thresholds from VE Configure 3 Inverter tab (the ones you listed) are ignored.

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nhenderson avatar image nhenderson seb71 commented ·

Thank you very much! However I don't see anywhere to make those settings neither in CCGX, nor in VE Configure 3 - help please!

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seb71 avatar image seb71 nhenderson commented ·

In VE Configure 3 you have to edit the ESS assistant.

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nhenderson avatar image nhenderson seb71 commented ·

makes sense however, I see no Edit option!veconfig.jpg

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