（2） 掉电时需要保存这部分需量数据，上电的时候读取，并根据时间周期来

（2） 掉电时需要保存这部分需量数据，上电的时候读取，并根据时间周期来计算需量。

結果 (英文) 1:

(2) this part needs to be saved when the power demand data when read on, and according to the time period required.

結果 (英文) 2:

(2) the need to preserve this part when power demand data, the power of time to read, and depending on the time period used to calculate the required amount.

結果 (英文) 3:

(2) when the power is off the need to save this part of demand data, when power on reading, and to calculate the required amount according to the time period.