In some parts of the world, electric vehicles may not look like them, but compared with traditional modes of transportation, electric vehicles are gaining more and more market share. The fastest growing part is electric bicycles. Some people say that the growth rate of electric bicycles is 16 times that of traditional bicycles (during the influenza pandemic, the growth rate of traditional bicycles is 15%). [Jacques mattheij] ride s-pedelec, a cross between mopeds and electric bicycles. There are some shortcomings, one of which is the poor scope and needs to be greatly upgraded.
The s-pedelec purchased by Jacques is technically considered a moped, which means it needs to drive in traffic. The 500 watt hour battery only needs 45 kilometers (about 28 miles) in a good weather, which is not too bad, but it will be a problem if your battery runs out in traffic and it is difficult to step on a heavy bicycle at the speed of a car. You can quickly replace the battery, but carrying a large number of unfixed spare batteries is a pain. You need to stop to replace the battery.
Adding more batteries has some challenges. The on-board BMS (battery management system) is very picky about digital rights management (DRM) and how many additional batteries it can add. Jacques’ solution is to add an external balancer. This allows him to add any number of cells while maintaining BMS satisfaction. The geometry of the battery is a little unstable because he wants the battery pack to remain in the frame. Placing it on the rear wheel will make the center of gravity higher, thus changing the handling of the bicycle. After a lot of research and preparation, [Jacques] re welded his customized batteries together with a spot welder. The final capacity is 2150wh (much better than the initial 500wh). Another benefit of the additional range is higher speed because the bicycle stays longer in the higher voltage domain. In eco mode, it can travel 500 km or 180 km at full power.
It is awesome and we look forward to seeing more electric bicycles in the future. Maybe one day we will have a Tesla coil wireless electric bicycle, but before that, we need a battery pack.