I've only ridden the Shimano system once; on a full day ride on a Merida e120-500E. My partner was also riding one of these, and she is lighter than me, but I had better battery life. We noticed this also when we rented some Levo's in Tasmania. I think she was a bit heavy on the boost mode . . . but also I was maintaining a higher cadence which might have helped. I also felt that the estimated 'range left' on the display was pretty inaccurate . . ..Rider wieght certainly seems to make a huge difference , last week we rode the 18mile Black route at Glentress a few times , I used eco almost all the way to the top , Iam 100 kilo the other 2 on identical bikes used trail and I believe some boost ?at times they are around 85 kg . My battery didn’t seem to be lasting much longer than the other two . We also found after dropping to 2 bars shortly before stopping for a 10 min rest the battery was showing 3 bars again when we set off again .
After 2 bars the shimano battery will suddenly drop to one red bar on the display , however I noticed my battery still showing 2 bars . I’ve not pushed it much past this stage so no idea how far it will go .
The range prediction is certainly meaningless and if you go by that I believe you’ll end up pedaling a dead bike .