Thank you for the arithmetic. I'm new to the electrical/electronic side of cycling, and I have a related project. I have a 36v e-bike I'd like to use for long-distance travel. I'd like to use the car jumper I already have to charge a second battery if need be. I can use your arithmetic to see if that's realistic or if I need to settle for a 50-mile range between charges, go solar, or what.