Dogma F ideal Di2 wire length?

[ccie6872]

For those who recently built a Dogma F, what is the ideal length (to avoid excess slack) for the di2 wire for the RD and FD with the battery now going near the BB? (size 540 / shimano 9270)

[Ritxis]

If you know where you are going to place the battery. measure up to the derailleurs and give the margin that you think is convenient so that you don't have too much cable and you don't run out

[BigBoyND]

Shimano manual tells you exactly what points to measure and how much to add