Got an email yesterday from fellow hybrid bike enthusiast, Larry Blakely. He built a front-wheel drive version of my bike — and just for kicks, a solar charger to go with it:
Things have come together. A Crystalyte 408 front hub motor, a 36-72 volt 40 amp controller, and 6 intact DeWalt batteries (2S3P) get me to town to do errands and return home on about 60% of the battery capacity. A big tip of my helmet to biodiversivist for showing how well this combo works!
Some data:
The latest trip was 14 miles total, and consumed 4024 mAh / 263 Watt hrs.
Battery capacities:
One DeWalt pack: nominal voltage, 33; mAh, 2300; Whr, 75.
Two DeWalt packs in series: v, 66; mAh, 2300; Whr, 150.
Six DeWalt packs 2S3P: v, 66; mAh, 6900; Whr, 450.Total elevation gain on the trip: 517′.
Average Watt-hrs per mile: 19.
Watt-hrs per mile on more or less level terrain: 11 Watt-hrs per mile
Around town: 13
Watt-hrs per mile on the last 2.5 miles up the hill to home: 44
Max amp draw 30.5 for a few seconds (when v = 61.7, watts = 1882)It took about 4 hours to recharge the batteries with the six 60W panel array.
We exchanged a few more emails discussing battery problems and solutions, exchanging links and ideas. He concluded by saying “Too much fun.” You see, while other people get a charge from things like crossword puzzles and Sudoku, nerds get their jollies from blowing up battery packs, tearing them apart to find out what happened, fixing them, and bragging to other nerds how they did it. The only new piece of technology in Larry’s system is the energy storage device. It is the link joining two old pieces of technology together.
His bike and panels are an example of an extremely efficient use of renewably generated electricity — URGE2. This rig cost maybe one or two house payments, but it may also be an example of how to grow an economy without destroying a planet. It all depends on how you choose to spend your money. In the not-too-distant future we will have options like plug-in hybrids, hybrid bikes, solar powered homes, and things not yet envisioned to pick from.
They won’t be inexpensive at first, but that’s OK — high cost imparts high status, and in this way the well-off fund development and start-up costs. Those less well-off wanting to emulate them provide a market, and therefore an incentive, for mass production — which brings costs down. The well-off move on to the next hot green status symbol. Repeat. Today, each battery pack, which consists of 10 cells, a circuit board, and a plastic case, costs $170 retail. Contrast this to the bike I mounted them on, a collection of hundreds of machined aluminum and steel parts, which also costs $170. Harness human nature and its embodiment in the power of the free market in service of the planet.
