      MBHoldingRegister[0] = battery_voltage;
      MBHoldingRegister[1] = pv_voltage;
      MBHoldingRegister[2] = charge_current;
      MBHoldingRegister[3] = load_current;
      MBHoldingRegister[4] = over_discharge_voltage;
      MBHoldingRegister[5] = battery_full_voltage;
      MBHoldingRegister[6] = load;
      MBHoldingRegister[7] = overload;
      MBHoldingRegister[8] = load_short_circuit;
      MBHoldingRegister[9] = battery_overload;
      MBHoldingRegister[10] = over_discharge;
      MBHoldingRegister[11] = battery_full;
      MBHoldingRegister[12] = charging_indicator;
      MBHoldingRegister[13] = battery_temp;
      MBHoldingRegister[14] = reserved_13;
      MBHoldingRegister[15] = reserved_14;
      MBHoldingRegister[16] = reserved_24;
      MBHoldingRegister[17] = reserved_31;