I was looking at electric bikes and thought they are doing it wrong. The battery is a large stack of lithium batteries that slide into a cartridge at the back of the bike. The electric motor is over powered. Everything they do makes the price of the bike unnecessary.
I was looking on the Amazon website at cylinder batteries such as AAA AA C and D types. You won't believe this but many rechargable c bateries produce 5,000 milliamps. That is 5 amps, about 60 watts of power each. They are only 1 and a half volts but that is ok because when you put batteries together end to end the voltage is doubled up. What I am saying is that with just 8 c batteries you can have 12 volts or 40 amps although would wouldn't get more current if they are connected end to end. You would need to connect them in parallel to increase the amps. To me 5 amps is an enormous amount of power. And the c batteries would fit inside the bike frame. The tubing of a typical bike frame is just over 30 millimeters. C batteries are less than 30 millimeters (3 cm) so If I made electric bikes, the tubing of the bike frame would have a plastic cylendrical holder and connectors to hold an array of 8 batteries. The 8 batteries would be cheap because they are not specifically made for bikes and are standard batteries. Plus if there is no time to charge the batteries, then they could be removed and swapped for freshly charged ones.
If I built an electric bike, it would have a tiny and weak electric motor but the motor would have a gear system that converts speed into force so if the motor is spinning at 1000 rpm then I would attach gears that have a final turn ratio that is one tenth so it gets more power and slower speeds that are ok for bikes. It doesn't take much power to push a pedal bike and I can certainly see where the power can come from.
