I own an izip urban cruiser, 24v 10ah lithium battery located in the down tube, 250w rear hub motor. It has a simple peddle assist system that senses torque and get between 15 and 18 mile range on a single charge. My commute to work, however, is about 25 miles. I am looking to add a battery to extend my range. Is anyone familiar with this bike or done a similar project?
I am thinking the Ping 24v 10Ah LiFeP04 would fit nicely on a back rack and give me what I need as far as range. I could probably figure out what connectors and switch would work but any advice or tips are welcome.

Thanks,
Tim
Seal Beach, California, USA

Here is a schematic: