DeWalt/A123 batteries

Warning: Creating default object from empty value in taxonomy_term_page() (line 33 of /home/robogeek1/

Ebike: Giant Sedona + A123 + WIlderness Energy

Typical range: 
17 miles
Top speed: 

Ebike 2.0 Li

Chris Beatty
July 8, 2007

My second Ebike is based on a 2006 Giant Sedona ($200) with a few minor alterations. The motor is a Wilderness Energy brushed 36V (BD-36) ($325). The original battery was an 8 Ahr NiMH. Top speed on the flat was about 23-24 mph at first and faded down as the battery drained. After only about 200 miles, it was already losing some range. My commute is 14 miles one way and I don’t like dragging a big pack of nickel uphill.

I purchased 5 DeWalt 36V lithium battery packs (~$100 each) which have 10 A123 M cells and a charge controller inside. I tried using one battery pack to see what the range and power would be like. It died immediately. With a bit browsing, I found out that there is a 15A internal fuse. The control module was dead, but the cells were ok. With the four remaining packs, the bike would only go 18-20 mph on the flat because the DeWalt packs are really only 33V (10*3.3V) and this motor really wants 36V or a bit more.

So, I broke the fifth pack into five pairs of cells and with some soldering and an in-line 10 A fuse for safety, I made four “piggy-back” packs that are ~40V.

I stuffed four of these into the rear bag on the rack.

OK, OK it’s not very pretty, but it was my first test. I will try to clean up the wiring.
Even so, it worked well. Top speed on the flat is 25-26 mph and the range is 17 miles with light but steady pedaling. Now the real trick will be to see how many cycles/miles I can get out of them.

Other stats:
8 AHr NiMH 13 lbs batteries only (.61 Ahr/lb)
11AHr Li 13.5 lbs with a lot of extra case plastic and 4 charge controllers
11Ahr Li 9.8 lbs batteries only (1.12 Ahr/lb) (almost 2x NiMH)

Seating capacity: 
Stock Giant Sedona Shimano
36v BD Wilderness Energy Brushed
Number of wheels: 
Wilderness Energy
DeWalt and homebuilt
DeWalt 36V packs plus 2 cell A123 "piggy back packs" (~40V total)
Miles as an EV: 
Conversion time and cost: 


Internal Combustion: How Corporations and Governments Addicted the World to Oil and Derailed the Alternatives
V3 Cycle Analyst for Electric Bikes Ebike Display The Cycle Analyst V3 dashboard with speedometer sensor and magnet is a great addition to any Ebike
Plug-in Hybrids: The Cars that will Recharge America
Carjacked: The Culture of the Automobile and Its Effect on Our Lives
JOLT!: The Impending Dominance Of The Electric Car And Why America Must Take Charge
Reinventing the Automobile: Personal Urban Mobility for the 21st Century

Who's new

  • Kevin Illig
  • Howard_C
  • k-Tracker
  • Camon
  • Sunder
Customize This