Evening to all. I have noticed something strange on my inverter setup. Setup is Axpert VMIII 5KV , 2x Pylon 2000 and 2000W PV (for now). So, whenever the batteries are not being charged, by any means when SOC is 25 or 100%, there is a 30w - 90w discharge from the batteries. ICC shows 0.4A - 1.8A battery disharge, even running from Utility. Any ideas please?

On this graph you can see the constant slow decrease of Volts, SOC and a constant -2Amp draw. (At the yellow dot I just commanded to charge from AC for monitoring.)

1 hour ago, fvanz said:

Any ideas please?

This is the Axpert's own power consumption, which it always draws from batteries (even when running in utility mode)

I have an older Axpert and mine draws just over 40W

1 hour ago, wolfandy said:

This is the Axpert's own power consumption, which it always draws from batteries (even when running in utility mode)

I have an older Axpert and mine draws just over 40W

Ok thank you. Just wondering why it uses 80W at times? Maybe fans?  It can draw 800W during the course of the night, that's almost 20% of my storage! (2x US2000 Pylons).

2 hours ago, fvanz said:

there is a 30w - 90w discharge from the batteries

As woldandy replied, this is the self-consumption of the Axpert. 90W is quite high, though I am not familiar with the Axperts specifically.

4 minutes ago, fvanz said:

Ok thank you. Just wondering why it uses 80W at times? Maybe fans?  It can draw 800W during the course of the night, that's almost 20% of my storage! (2x US2000 Pylons).

I highly doubt it can be the fans. Those 120mm fans don't draw more than 10W on full blast (as far as I am aware).

8 minutes ago, jykenmynie said:

As woldandy replied, this is the self-consumption of the Axpert. 90W is quite high, though I am not familiar with the Axperts specifically.

I am not sure about the Axpert, but its brother, The infinisolars could draw up to 130Watts to keep itself going. 

43 minutes ago, Jaco de Jongh said:

I am not sure about the Axpert, but its brother, The infinisolars could draw up to 130Watts to keep itself going. 

Joh that is quite high. My MP II 5kVA only seems to use around 40-50W itself.

@fvanz It might be that your battery stack is a little small for the inverter you've got (both for the reason that 80W from the inverter seems high and that the current it can continuously provide isn't enough for your max load). I think for a max nominal load of 5kVA, they'd recommend having 4xUS2000. My 2xUS3000 is also technically too low for my 5kVA inverter, so I am considering adding another at some point in the future.

4 hours ago, fvanz said:

Just wondering why it uses 80W at times?

It likely doesn't actually have 80 W of self consumption. Axperts report PV and battery current in whole amps, so you tend to get large errors in measuring self-consumption at the low power end. If you have a DC clamp meter (remember to zero it and pay attention to drift, I find the 400 A range best), you can probably measure the battery current more accurately, to about a tenth of one amp.

Yes, the high self consumption is annoying, and has to be taken into account when sizing a system.