I have a new Sol-ark 15k and Homegrid 5-stack (500ah) LifeP04 battery. They are connected together with closed-loop communications. Charging voltage is set by the BMS at 53.2V. As soon as charging stops, voltage drops rapidly to 49.9V, but shows 100% SOC. Is that normal? I don't have a load on the battery yet, so no charge/discharge cycles.