On Aug 28, 2014, at 12:07 PM, Ed Blackmond via EV <[email protected]> wrote:
> In the leasing model, battery packs have a guaranteed capacity. It does > not have a guaranteed manufacture date. That implies a corollary: that you might buy the car with a lease on a 24 kWh battery...but are you still going to pay the same lease rate for that battery a couple years later when it's only a 20 kWh battery? Is the car going to report its battery capacity to the leasing agency, and you have a variable payment based on capacity? Will you be penalized if you run the car hard and the battery loses capacity faster than average? Will there be seasonal adjustments in extreme climates? A Tesla battery swap can be done in under two minutes, but I'm gonna take a wild guess and suggest that a Leaf battery swap is no less than an hour of shop time, conceivably a few hours if they didn't design it with ease-of-access in mind. If you have a 20 kWh battery as your daily driver and need a 90 kWh battery for your vacation trip, is it worth paying a couple hundred dollars in labor just for the privilege? Either *somebody* is going to have to eat those shop time costs (and that somebody will inevitably be you) or else the car is going to have to be designed for rapid swapping. But the engineering for rapid swapping is only going to make sense if it's a common occurrence, such as what Tesla anticipates for their charging station. An hour or three of labor every several years to swap end-of-service-life batteries is more than fast enough, but you need to get a battery swap to be the same type of job as a tire rotation for a lease model to make sense -- fast and easy, with no special skills required. And the engineering for that is probably not that far off the engineering for Tesla's automated 90-second swap. Then there's also the question of standardized battery packs, at least within a manufacturer's product lineup if not across all manufacturers. That probably won't happen until batteries have energy densities akin to gasoline. At that point, you can imagine a standardized suitcase-sized module that you just hoist into place; until then, we're going to continue to see batteries in all sorts of weird shapes and sizes and locations to accommodate different vehicle configurations. That's especially the case with today's EVs with their weight- and drag-induced design restrictions. It's a great idea, but I don't see it meeting a practical intersection of price and value before battery technology simply gets to the point that your BEV econobox has a multiple-hundred mile range with battery pack lifetimes comparable to today's ICE cars's engines and transmissions. On the other hand, if batteries _don't_ improve at the pace one might anticipate, that could well be the route the industry winds up taking. Cheers, b& -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 801 bytes Desc: Message signed with OpenPGP using GPGMail URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140828/0c59f725/attachment.pgp> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
