Is one of my B300 defect?

I’ve started with an AC300 (EU version) + one B300. This worked fine but my panels are able to produce more than the 3 kWh per day and I was not able to consume it during lunchtime so I bought a second B300.
With the second B300 connected the SoC indicator act’s weird.

For example yesterday, SoC was around 60% and about 300W coming from PV. The AC300 is not connected to the Grid. Suddenly the SoC went to ~80% within a few minutes and afterward to ~95%.

In the afternoon I ran a water pump (0,6 kWh) the dishwasher (1,1 kWh) and the washing machine (0,6 kWh) which brought the SoC down to ~60% again. So far so good.

Afterward, I started a tumble dryer which consumed about 1,5 kWh. Within an hour the SoC went down from 60% to 10% and I had to connect the AC300 AC Input to the grid from which it consumed about 0,5kWh.

So in total getting 3,3 kWh out of the batteries brought down SoC from 95% to 10%. At the same time, PV was still generating Input (between 300 and 700W). It looks as if the second battery has no effect at all.

I have observed the thing with the SoC jumping up while charing already several times.

Hi @Ron , When connecting two B300s, could you please check the battery information in the interface to see if there is any abnormality, such as whether both battery packs are recognized. Look forward to your updates.

It looks fine in the interface (screen on AC300) and in the App. Currently, the overall SoC is 14%, Battery 1 is at 15% and Battery 2 is at 13%.

Currently, I am using both battery connection ports of the AC300, each connected with one battery.

I’ve also checked the Batteries in the App. One is at Version v1014.13 and the other is on v1021.06.
Checking for Update says that both are up to date.

Hi @Ron , Thanks for the confirmation. Can you split the difference in power consumption time by connecting only one B300 with a 1500W dryer on two occasions and see the difference?

If the power consumption times are about the same, it may be caused by the higher instantaneous power of the dryer.
If the power consumption time of one B300 is much shorter than the other, then the B300 with less power consumption time is the problem.

Not sure what exactly you want me to try. Should I test how long I can draw 1500W (from 100-0% SoC) with each battery separately?
This is how it looked like today. The top graphs are the the battery Levels (Battery 1, Battery 2, Total) and the bottom graph is the PV Input in Watts.
At around 1:22 PM the overall SoC went up from 52% to 80% at 1:27 PM so within 5min. This would mean ~1700 Wh within 5 min which would mean an Input of 20kW.
What’s interesting is that both batteries SoC increased. Battery 1 from 57% to 80% and Battery 2 from 47 to 80%.

Hi @Ron , Thank you for the test confirmation and the data. You can try to connect AC300 with two B300s, first empty all the power, then charge to 100% (do not carry any equipment during charging). Repeat twice to do a machine power self-learning.
After the machine does the above power regulation, you can use again to see if the batteries will still appear in use will be abnormal charging and discharging phenomenon.