Lots of bike work in the past couple of weeks. The new sprocket arrived AND… it’s not a plain sprocket, meaning it has a collar with a set screw. Worse yet, it doesn’t easily line up with the generator shaft. Doh! Ben kindly offered to use his CNC to cut the center out of the sprocket, but I decided to go back to the beginning and see if I can’t find a better way. It’s a lot of work to get this motor to generate a high enough voltage to charge the 24v batteries. If I move to 36v or 48v, I’ll have an insurmountable problem.
After some recent thread about the MY1018 motor, it turns out the sprocket on the end of the shaft is for 1/2″ by 1/8″ bicycle chain. I dug through a box of old chains and found one that fits. I had to reverse the sprockets on a crank (they bolt on, so I bolted them to the wrong side of the crank) and was able to mount the chain. Now, the reason I never used bicycle chain was that the gearing isn’t high enough.
So what I did was instead of charging the whole pack, I hooked the motor up to one battery. And it works.
I put a volt meter and ammeter on. There is very little resistance at low rpm, but then once the generator voltage exceeds the battery voltage, you feel the resistance kick in. The highest voltage I achieved was 16V (with the batteries attached) and the maximum current was about 10-15amps. The average current was about 7amps, and the average voltage about 14.5V.
One quick note, the generator mounting holes did not fit well for the bicycle chain like they did for the no.25. I used some washers to make it work for now. To test how well the setup works, connect the positive and negative leads of the generator motor. This is the most resistance you will encounter while pedaling. If the setup survives this, you’re probably good to go.