NiCads can also be discharged to zero SoC, or even reversed without damage. They seem indestructible. A local guy has a bunch he got out of salvaged electric buses, been using them for years. But like sla they don't have high energy density, so add a lot of weight to a vehicle. Titanate is fairly low too, about 70 Wh/kg specific energy, but valued for some applications due to its very high specific power. Proterra uses them in some of their buses since they permit high charging rates.
Myself, I would like to see Tesla offer modular packs for vehicles, in say 10kWh increments, with a few options for voltage and Ah per module. I could install around 40kWh in my vehicle for about the same weight as my current 20 kWh LiFePO4, provided they don't add too much weight with the packaging and temperature control system. They could specify flow and head pressure requirements for the cooling system and use standard connectors so you just hook up electrical, plumbing, and are ready to go. I expect such a pack would cost more than I would like currently though. The $3k per 7kWh is too high. Our power goes out around half a dozen times per year, typically for 4 to 8 hours. We just use headlamps and go out to dinner or lunch if necessary. I've thought about battery back up for our grid tied solar, but its just too expensive. A generator is much cheaper, and would contribute little CO2 since it would run so infrequently - much less than a plug in hybrid adds if driven much beyond its electric range fairly frequently. >From what I've read Tesla is targeting mainly companies in states where they can have significant savings by using backup power during peak usage, high rate, times of day, giving sufficient pay back for the investment. I think some companies are currently using solar arrays for a similar purpose. -- View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Re-Tesla-plugs-into-new-market-with-home-battery-system-backup-foolishness-tp4675252p4675281.html Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com. _______________________________________________ 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)
