----- Original Message ---- From: Terry Blanton
> Lithium battery charge efficiency is quite poor above 90 deg F. And where > are we gonna charge our Volts? Maybe not in the hot garage in Phoenix. Speaking of hot batteries, Terry ... you may have seen this older story: http://pepei.pennnet.com/display_article/155624/6/ARCHI/none/PRODJ/1/AEP-dedicates-first-US-use-of-stationary-sodium-sulfur-battery/ ... matter of fact - in looking in the archives - we mentioned it here last year: http://www.mail-archive.com/[email protected]/msg22390.html The industrial-scale battery uses sodium metal instead of lithium. This could be telling us something about possible missed opportunities. The big problem - the battery only works when it is rather hot - like 500F and up - which is no problem for industrial sites. http://www.electricitystorage.org/tech/technologies_technologies_nas.htm However, if the PHEV car owner is willing to charge up his vehicle every night anyway at off-peak rates where it is easy to keep the battery hot ; and given that we have this great insulation material called frozen-smoke (aerogel) ... which should present the situation where heat loss can be minimized -- And given Ford was once a big player in this tech ... then why isn't this even being considered as viable - or is it? Jones Here is an 11 year old Canadian abstract - and it makes you wonder about the "seven companies" not to mention China and India - so - possibly this battery will not be a missed opportunity after all... just missed by the big-3. D. Sodium-Sulphur Batteries The Ford Motor Company used a sodium-sulphur (NaS) battery in its 1992 Ecostar because it offered three to four times the energy density of lead-acid batteries; in other words, a physically smaller battery could provide the same power. The NaS battery also has a range of about 241 km, roughly twice that of an EV powered with lead-acid batteries. This technology, however, has not received widespread acceptance for a number of reasons. For one, it is not considered "user friendly." Because one of the electrodes is made of molten sulphur, the battery must be kept at a temperature of 300 to 350ºC. To keep the sulphur, and the sodium, from solidifying, the batteries have built-in heaters. As a result of these stringent operating requirements, NaS batteries currently cost seven times as much as lead-acid batteries. In addition, safety concerns were raised when two Ford test vehicles caught fire while using NaS batteries. This technology is not likely to emerge as an early leader in the race to find the best battery for electric vehicles. Companies in at least seven countries believe that it offers great potential, however, since it uses relatively cheap, abundant materials. These companies are all working to build on the advantages of the technology, while ridding it of its more troublesome problems. **As with any of these new battery technologies, mass production could quickly reduce costs.**
