G'day Moss, I have the same D30 and mainly ride it in 'Me" mode. Initially I was told about 100 ks from a full charge but I now find my App indicates up to 485 ks. Possible as I don't rely heavily on the assistance.
I have an Orbea Gain D30 and I have noticed on the last couple of rides that the Assistance Selection buttons on my iPhone "Grey Out" after about 40ks and I cannot change my selection. I can still adjust the levels from the top tube and it registers on my phone.
Any one have any ideas please?