I was wondering on the generic e-bike how much distance would you get on a charge. On the website it says 20 to 25 miles per charge. I have the IZIP 24V10A Battery which is rated at 12 to 20 miles per charge. However, I only get around 9 miles per charge. I do pedal the entire time. I do have the some big hills on my commute. Any insight would be appreciated.