My first run to an empty pack
I just finished finding my true range for the first time. I haven't charged my car since last Wednesday. I've been driving to work and back (10 miles), and to the driving range, again in town. I got home with the odometer reading 67 miles, and I thought I would drive close to my house until my BMS told me I had a cell too low. I drove a route that was mostly 40 to 45 mph, and probably had about 20 stops and starts. I ended up with 101 miles!!! My odometer is off slightly so I think it was really 112 when all done. When the BMS said I had used 80% of the pack, my batteries still read 3.25 volts. I have 38 160AH Thundersky cells in my car. I had my Elithion BMS set up to post a low battery fault at 2.7 volts. I have that signal connected to a light in my dash and to my Soliton Jr. Controller. I had set up the controller so that if the warning light came on, it would only deliver 50 amps. It all worked fine. I was able to get another 3.5 miles out of the car, and there was probably a couple of miles still left. At rest my low cells were reading 2.96 volts. With a 50 amp load they would sag to 2.8 volts.
My cells came from Evolve electrics here in Boulder. They had these used cells from a university that only had 20 cycles on them. When I heard that, I thought these might be a great deal because any really bad cells had probably been culled. I think I was correct. I definitely have a well balanced pack. The highest resting voltage I saw was 3.09 volts. So I think my lightened flywheel, weight reduced bumper, and loosing the luggage rack have paid off.
As you can tell, I'm really excited. I have solar panels on my house, and I looked at my production today. It was 42 Kwh. It's a good time of year for solar. That means in half a day of solar production I can drive 110 miles. (19.6 Kwh pack)
Frank Bernett -- '77 MG Midget, 19.6 Kwh LiFePo, Warp 9 Impulse, Soliton Jr., Elithion BMS