question

If with the same load it only shuts down when the panels are not producing power, probably it's not the inverter.

Dear Seb71,

The charger delivers 13.5v at all times in bulk and float, and above 14v in absorption.

The battery bank does go down to 12.3v as mentionned and it's normal under load, it has been verified on the BMV display. Then why is the inverter shutting down, even though it is set to at 9v? Do you want me to post a video to illustrate my question?

Here is the response I sent to the dealer:

Dear Axel,

Here is my answer:

There are chances that the voltage of the batteries drops too low in voltage

12.2v at the lowest displayed on the BMV

therefore the amperage increases and the inverter goes into default by the increase in amperage.

If the voltage goes down, then the amperage will go down. I don't know of a single battery on the market that will increase amperage because its internal resistance has increased. If so, maybe we'd have some free energy, which would be great to exploit in the future.

The more the batteries are used, the more the voltage drops when you have a current draw.

These batteries are a bit tired, however, given the number of cells, 500w does indeed drop the voltage to not more than 12.4v from when they are new. Delivering 500w shouldn't be a problem for the inverter, period.

The compressor can draw quite a large current draw. The inrush current as well as the wear of the batteries would explain the failure of the inverter.

It's a generic brand Lithium battery charger, while the one I had previously was a Swiss brand, maybe that's the problem. In my humble opinion, incriminating the inverter is probably on the wrong track.

1 - It will run for 5-10 seconds (this dismisses the ignition claim)

2 - The voltage drops to 12.2v

3 - The inverter shuts down of an alledged overpower.

I think it's an internal conflict due to the electronics of the charger which has too few protections. Or else, it's still this low-end cooler that's making a big deal out of it.

I'll try unplugging the cooler, and if that doesn't work, I'll try running 500w at home with a more robustly designed device and get back to you with the outcome.

I did a test at home today with Victron Connect. It displays the correct voltage 13.3v, same as the monitor.

When I put the charger online, it draws the usual 300 odd watts but the software gives a battery low voltage warning displaying 12.0v. The battery monitor displays 12.6v as its under load, this one looks normal as I have over 500Ah on AGM batteries fully charged.

At this stage, I would trust the battery monitor as (I'm well rounded with battery experiments, it's my job) the result from the inverter seems to be stuffed.

A few seconds later, the inverter shuts down as for him, the battery voltage is down to 11.9v (we are still way off the 9.3v cut off but...) and the monitor continue displaying something more consistant around 12.6v

I did indeed ran a test with another load. I have a concrete drill that uses 500w. The inverter delivered the full power for a few seconds, however, the exact same thing happens.

It was noted that if the sun is shining, this will happen as well, however it will keep the shut down occurring.

We have discrepancy between the 2 meters. I have no clue at this stage why the inverter is so pessimistic with its voltage read. The system is wired up exactly like on the BMV diagram.

My question is: How does the inverter gives a false reading of the voltage that is consistant with the load curve but is however exaggerated?

And then: What can I do to fix that fast, do I have to make the BMV master of the circuit?

Thanks

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Hi.

Did you get an answer on this ? I'm experiencing similar issues and trying to work out if i can do anything.

Thanks

Phill