Jon "Sheer" Pullen wrote: > > A stopwatch and a clear section of flat road? ;^> > > Tests done tonight indicate you are correct.. after driving > the car 90 miles today, I did a 0-60 test and got about 13.5s > with just me in the car. There may be some error in that > number, as the road was not exactly flat [maybe 1% uphill > grade], but it's probably close enough to validate your point. > > I genuinely thought she was faster. Ah well..
Wait a minute; unless what you wrote is a typo, the only thing your test validated that I wrote is that a stopwatch and clear section of road is all you need to test your 0-60 time. ;^> 14s was the target, and if you did ~13.5s then you are doing better than I expected, even with just you on board. Sure, you won't hit 14s fully loaded, but it looks like you won't miss it by a factor of 2. > I don't have any idea how far I am stressing the frame of my > car. I can only say that if Victor's CRX hasn't folded in > half yet, I feel pretty comfortable driving my Accord around. > I figure his will fail first, then I'll know what to beef up > on mine. ;-) <GRIN> > > But they do warm up somewhat on discharge, and if they > > start off in a 90-100F+ ambient, you could very well > > require some cooling before you 90-100F+ could > > safely plug them in to charge immediately upon reaching your > > destination. > > I still don't follow you - if you're exceeding the temp > limits for the pack while driving, that's a problem while > driving, not while charging. OK, let me try again: the car is sitting in a 90-100F+ ambient, you get in and make some sort of trip, drawing sufficient current to heat the batteries further. When you park at your destination and immediately plug in, the batteries are still too hot to permit charging unless you have a thermal management system working to keep them at an appropriate temperature the whole time. Remember, the manual states the max temperature for discharging (driving) as 60C (140F), but the limit for charging is specified as just 35C (95F), so quite a bit of heating can occur while driving before it becomes a discharge problem, but it doesn't take much to cause a charge problem. (Even in Vancouver summertime temperatures can get warm enough that a pack of Evercels could exceed 95F at the end of a drive.) In any event, it is not so much of a concern to me whether the heating is a driving or charging issue; either substantiates the need for a proper temperature management system for these batteries if an EV using them is to be widely usable and satisfy the plug-and-play requirement of this exercise. And note that NiCd, NiMH, PbA also all need thermal management of some sort too; I am not singling out NiZn here. If anything, I am singling out NaNiCl as an example of a battery that has simpler thermal management issues (heating only), and includes the solution as part of the package that you buy. > The batteries cool off pretty > quickly once you take a load off them - 40 lbs just isnt that > much thermal mass - so I really don't see this as a issue. Ah, but you don't have a single 40lb battery with air circulating all around it, do you? You have a bunch of them packed more or less tightly together in some sort of box, forming ~440lb blocks of thermal mass (assuming 22 model 100s evenly divided between 2 boxes). With respect to plug-and-play, it doesn't help that they cool 'quickly' if it means that when you get to your destination you can't just plug in, but have to leave the car sit for some amount of time, then return to confirm that the temperature has dropped acceptably so it is safe to charge. > Yes. The suspension upgrade also increased my aero losses > slightly. I'm hoping that adding a belly pan will get me back > some of the loss, but I haven't gotten that far yet. Can you explain what your suspension mods were, and how they increased aero losses? Rolling losses I would expect, but impacting on aero losses is a bit of a surprise. > Those are the numbers I was givin by evercel. Real world > testing has not bourne them out Does that mean you achieve more than the 89Ah value, or that you have achieved more than the 50 cycles without the capacity dropping to 83Ah? Both? Neither? Cheers, Roger.
