Epoch is the name for Valence's third-generation lithium phosphate batteries. These Epoch batteries were improved based on customer comments and concerns over earlier generations. In part because ABG reader kert wondered aloud about the price of these batteries, I set up an interview at EVS23 with Joel Sandahl, the vice president of engineering at Valence Technology. We sat down in the large expo hall and I asked him about these batteries, which are lithium phosphate and not lithium ion, and about the price. Guess which topic he was more willing to talk about?
Sandahl talks about the difference between lithium phosphate and lithium ion batteries, especially from a safety angle. It is his belief that the auto industry is turning towards lithium phosphate batteries because they are safer than lithium ion batteries in an accident (should I mention once again the thermal runway issues with laptop batteries? Nah). Another reason Sandahl is in favor of the Epoch batteries is the high cycle and calendar life of lithium phosphate batteries when compared to lithium ion ones (2,000 vs. 300-500 cycles). The Epoch batteries also feature a "fail soft" mode so a failure won't be caused by a single cell going out. The word is these batteries provide power at around $1 a watt hour.
Give Sandahl a listen here (17:30 min, 12 MB). The other voice you hear in the background is Helen Rodriguez, who helped set up the interview.