Hi Brian,
Thanks for the question. I would contact tech support about your battery range issue, as that is not typical, as long as the kit is being used properly.
The e-zip bike battery cell (24 volt, 10Ah) would work with the Hill Topper, but the motor controller, the piece of electronics that regulates how the power is sent to the motor, would not be compatible with the Hill Topper motor.
If you want to connect this battery cell, you will need one of these:
http://www.electric-bike-kit.com/controllerandchromeplug.aspxLet me know if this makes sense. Thanks.
p.s. I'm moving this post to the tech support forum.