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« on: August 13, 2017, 11:05:38 am »
So this is almost ready. I've redesigned the tube battery to make it smaller, lighter, less expensive, and with a slightly longer range. Oh and this one look cool because the outer case is transparent! That's right, you can see the actual cells!
Basically, a change in battery chemistry allowed me to switch from a 10s4p to a 10s3p due to an increase in capacity and amp output. The idea of the design is still the same, but reducing the total cells from 40 to 30 means an approximate 25% decrease in diameter, weight, and cost, yet the capacity is theoretically 5% greater!
The reduction in cell count means that each layer of the battery has two fewer cells, so I was able to rearrange them to fit in a smaller diameter CLEAR thick walled PET tube. This tube is a little more expensive than PVC, but the "cool factor" payoff is worth it.
I've finished the main design including wiring up the BMS and I am about to do some burn-in testing before closing everything up. While out riding the other day with it, I popped a rear tire and rode 2 miles on a flat rear tire at 17 MPH without pedaling! The battery and the wiring did not overheat, so I'd say initial tests are very promising.
Here's a pic with the new battery on the bike and the previous version on the floor.