E8000 battery issue

[jonk]

Hi, first post but long time reader.
Yesterday went riding with my friend and we were 20 miles into a ride with 1100m climbing under our belts. i have a 504w battery and was using eco mode for most of the ride. I came to very steep climb with 24% battery remaining, switched to boost and the system went to 0%!
My bike also has Di2 powered from the battery which still worked but, could anyone tell me why this happened?
The battery is still at 99% capacity.

Thanks!

 

[jimbob]

Do you ever fully discharge tge battery? Perhaps the battery management has got out of calibration and it was almost empty, and putting it into boost took the last remaining power? Seems a bit poor if so, but thats my first thought.