Friday, March 30, 2012

The more things change, the more they stay the same.

So after wishing I could throw in the towel on this bb600 pack aftermultiple incidents of spewage, ground and interpack shorts that melted holes through a dozen cells, and apparent loss of capacity down to about 16 Ah, Karmann Eclectric didn't get a lot of use after a fall recommissioning of the pack, but I cycled it a few times over the winter, took a few short drives, and got the Onan range extending genset trailer working, due largely to a lack of confidence in the pack. The car seemed to be sulking, especially when I added a 2012 Mitsubishi iMiEV to the fleet! Well, it seems that the pack was actually ready for prime time once again! Tonight, with a pack temp of 50 deg and outside temps a few degrees lower, I topped off the charge and took the car for a diciplined 45 minute drive, covering a 27 mile loop with only 4 stops at intersections, for an average speed of 34.8 mph and a peak speed of 68 mph (climbed up and coasted down a 127 foot incline twice at speed, with many other smaller climbs). The 200 cell pack came off a peak charge of 333V and rested at 305V after about 15 minutes, with 0.1 Ah of parasitic consumption before takeoff. I set off with headlights blazing and pulled into the garage 45 minutes and 27 miles later, having consumed a total of 31.1 Ah, or 6.82 kwh. That's 1.148 Ah per mile, or at an estimated average V of 230, a battery-to-wheels efficiency figure of 264 Wh per mile. Next time I'll reset the EMeter to report kWh instead of Ah, and then it'll be time for some data collection with the range trailer hooked up!

Not bad, considering that this was at night in a car with a very heavy-duty transaxle and series motor, while my iMiEV consumed 257 Wh/mile during a 51 mile conservative daytime drive (though it's the current king of regen, that trip was mostly highway). Hey, guess it's time to hit the road again and drive that same loop in the i!

Back on the road, and the iMiEV made the same run in the same time with apparent consumption from the pack of 7 kwh. Sorry, the guessometer doesn't get any more accurate than the nearest kwh per bar on the graph. That would match the Ghia's performanceof 6.82 apparent kwh. (I minimized regen by shifting into neutral and coasting or braking as required to better match the Ghia driving style.)

So Mitsu, whassup with that? You produce the most efficient vehicle ever rated by EPA, and it's no better or maybe EVen a bit worse than a homebuilt drag racer cobbled together out of surplus and rebuilt castoffs and a heavy truck tranny? Time for more tests and better instrumentation!

1 comment:

Anonymous said...

Jay always keeps one of the cleanest cars and pristine garages I ever had the pleasure of working with!
Roger Wright