replacement battery

Hey everyone! I’m new to this forum, so thanks in advance for your help! I purchased a used 2019 Rad Rover (since new ones are out of stock) and, unfortunately, the battery stopped working after about a mile. It had fully charged and just went to zero :-(. The previous owner admitted to not...

I have a 2010 Kalkhoff pro connect sport, which I have used a great deal. The battery has lasted a lot longer than I had expected but is now starting to fail. The bike has a 250w Panasonic center drive motor that runs at ~26 volts. Replacement batteries used to be readily available but I am...