Help with Conditional formula to compare two rows from a third column

Hi, Anonymous 

Please correct me if I wrongly understood your question.

please check the below, that is for the Calculated Column.

Battery START Column =
VAR currentID = Data[CustomerID]
VAR previousdatetime =
CALCULATE (
MAX ( Data[DateTime] ),
FILTER (
Data,
Data[DateTime] < EARLIER ( Data[DateTime] )
&& Data[CustomerID] = currentID
)
)
RETURN
COALESCE (
CALCULATE (
SUM ( Data[BatteryLVL] ),
FILTER (
Data,
Data[DateTime] = previousdatetime
&& Data[CustomerID] = currentID
)
),
0
)

Hi, My name is Jihwan Kim.

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