Friday, February 19, 2016

Bridget Stone's Diarygram - DIY Electric Bike Update

For those of you who read the first Bridget post, here's an update:

I downloaded a second bike-tracking app this week so that I could keep the regular bike stats separate from the electric bike stats. I want to keep track of how many miles I put on the e-bike this year. Since I travel mostly the same route to and from work, it made comparison of the two pretty easy. Check it out.

Wowser - 25 miles per hour!
There it is. The electric bike knocked 8 minutes off of my commute and raised my average speed by 3.5 mph. To be honest, the bike is a little more powerful than I want it to be, so I am planning to replace the controller with something a little less powerful and a little more dependable. The lithium battery pack has a little built-in breaker for surge protection. It keeps tripping when I try to take off. It takes more juice than the battery wants to give to get me rolling, so I take off pedaling and get up to speed. Then I gently roll on the throttle, and the battery pack may or may not shut itself off. I may or may not have to stop, turn the battery off and on again, and repeat the process. It's pretty darned annoying!
That's all there is to an electric bike.
For you technical types, here are a few specs:
Battery: 36 volt, 11.6 amp-hour, lithium-ion. (It's removable - I can take it inside to charge it.)
Motor (in the front wheel): Old Aotema direct-drive brushed hub motor - it's a beast
Controller: Generic Chinese 1000 watt controller
Throttle: Leftover from a Razor scooter (I wonder if the throttle is not a little of the shutting-off problem.)
Next steps:
I have been eyeing 36V 500W controllers on Ebay - less than $20 shipped. I still need to make some panniers (Goodwill Pound Store, here I come!) and try out the trailer. I may also need to do something about a kickstand.
Overall, I am very happy with the results. If I can drop her back to an 18mph bike that takes off easily and has a great deal more range, I will be even happier. This could be a great season for electric bike commuting and errand running.
May your green projects thrive and may you enjoy your commute too!