In late 2022 I purchased the B230 expansion battery as a backup to my AC200P system. That B230 charges the AC200P fine using the appropriate cables.
I recently purchased the AC200L and I hoped that it would also work with this AC200L. I first did a bunch of charge and discharge tests with the AC200L by itself and everything is working fine.
I then independently discharged this AC200L down to 70%, and fully charged the B230 to 100% using an AC adapter power brick.
I attached the two units through their battery expansion ports using the P090A to P090A cable making sure to switch both ends to LOCK with a click sound. After a few seconds the AC200L display reads 85% and the expansion battery detection light (top left corner) appears on the display. 85% is the average of initial AC200L SOC (70%) and initial B230 SOC (100%), so I thought the connection was good.
I then turned on AC output on the AC200L and plugged in a 700W dehumidifier unit. Turning on the dehumidifier shows around 700W AC output on the AC200L screen but the AC input reads ZERO. Running the dehumidifier for a while with the AC200L + B230 connected, and then disconnecting them, shows that ONLY the AC200L has been drained below 70%, while the B230 is still 100% (based on its indicator lights). This indicates that there was no actual charge transfer and/or charge equalization between the two units.
What is the problem here? Do I need to download the app and do some kind of firmware or BMS update or something? I thought the P090A to P090A cable was a “plug and play” instant detection and charge/discharge transfer between the B230 and AC200L ?