As I see it, the model for successful battery exchange in EVs is the lowly flashlight (torch). The cells come in 4 basic sizes, with two of these most commonly used (AA and D). Effectively, you have 2 or maybe 4 tiers of energy content and power capacity; then, within each tier, you use more cells to get more of both.
To make battery exchange work with EVs, you'd have to get all the EV manufacturers to agree on one or two standard module sizes. They'd need standardized connections that mate as the battery is installed, just as flashlight battery connections do. You'd have different capacities (through different chemistries) in a given module size, and also vary the capacity by the number of modules the EV used. For affordability and convenience, you'd have to fully automate the exchange process. The driver would pull into the exchange bay, pay the operator, wait a couple of minutes, and drive out with a freshly charged battery. Most likely the modules would have to attach from the bottom, with hydraulic lifts and conveyors doing the work. You could have one pit to remove the spent battery, and another to raise a fresh one into place. The EV would be moved from one pit to the next on tracks. You should be able to exchange an EV's battery even faster than a gas pump can fill an ICEV's tank. This model might have worked IF all the EV manufacturers could have agreed on it from the start. But making that happen would have been a huge challenge, and now it's just about impossible. Then, building all the exchange stations would require a stupendous investment. All this is pretty daunting. Just ask Shai Agassi. So, I wouldn't say that battery exchange is a stupid idea, but I'm afraid it's not a very practical one. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to "evpost" and "etpost" addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = _______________________________________________ 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)
