Category Archives: Dark City Projects

Will the real mosfet please stand up ?

This information will save anyone with a speed controller time and cash..... The chances are that most of us have a few IRFB 4110 mosfets, they are to be found in most KT speed controllers. You can get 20 x IRFB 4110 mosfets of Ebay for £7, this does not seem a bad deal, if…

The Saga of The Rear Hub Wheel

After blowing a 1500w KT speed controller, and refitting a new speed controller (KT copy bought as original KT), the bike once again had power to the motor. The wheel sounded fine when spinning off the ground. When riding which put the wheel under load, we discovered the wheel was making a grinding sound. We…

The Rack Battery

The Rack Battery Design and Build Ebike battery packs are made from lithium ion cells which provide 3.7v (3.6v for ours) nominal voltage and charge upto 4.2v and can go down to around 3.1v safely with longevity. When cells are connected end to end (serial) the voltages are combined, so 13 cells end to…

The Ebike Project – Page 2 – Bob’s Battery

Bobs Bigger Battery Bike Bobs bike before with a 20Ah lipstick battery in the grey and purple bag. The speed controller and wiring is in the triangular frame. We wanted to design a better battery for Bob's Ebike to replace his 20Ah 48v lipstick battery, we decided originally on a 30Ah 48.1v battery but…