Hi everyone,
I recently added 14 new BYD LVL15.4 (model 2021) batteries to my existing battery pack of 10x BYD LVL15.4 . I reconfigured the BMU for the 24 battery packs and i updated the BMU and BMS of all batteries to te latest (V1.17 BMS) firmware. The installation has 3 Quattro’s (15000) for a 3 phase system.
Everything is working fine as long as the SoC is below 100%. When reaching 100% The BMU displays a battery voltage of 56.1V. When there is no longer solar production (AC coupled PV, 30kW) the Battery SoC is going down but the voltage of the battery keeps displaying 56.1V even when the battery SoC has going down to 50%. This prevents the batteries of being charged when the PV is starting up again the next morning.
When i connect to the BYD BMU, it shows the 56.1V so victron receives this value of the BMU. After rebooting the BMU, the battery voltage is correct again (±52V) and the battery starts charging.
When i added the new batteries to the old pack, i made sure that the voltage was in the same range and the SoC of the old pack was around 30% (should be the factory SoC of the new batteries as well).
Does anyone have any advise what is going wrong?