Hello, I bought a Tech Townie 'electra' 7 speed ...step through. It was once stolen and stripped. I have piece by piece put it back together. I am into it about 400 bucks (and a lot of time) The battery is still missing, and the price of the "factory replacement" is a deal breaker. I intended to build my own battery but it seems the esc responsibilities are shared by the factory battery pack and the esc look alike that mounts to the bike. I'm inclined to find an aftermarket (bafang or whatever speed control.. and go back to making the battery pack myself. Is pedal assist torque sensor going to work or am I digging a deeper rathole to get lost in. What I really need is a dead factory battery .. good luck finding one here in Hawaii Thanks in advance