Greg_E 211 Posted October 17, 2012 Share Posted October 17, 2012 Bad news for the electric Spark: http://autos.yahoo.com/blogs/motoramic/battery-builder-a123-won-249-million-federal-grant-143806554.html Link to post Share on other sites
Benjamin Nead 1 Posted October 17, 2012 Share Posted October 17, 2012 Yeah, Greg, the A123 bankruptcy is certainly not good news. Note, though, that A123's assets (presumably including technology) is to be bought up by Johnson Control. It's doubtful that anything is going to be dumped in the trash or suppressed. The A123 NXT technology, in particular, will be quite valuable to them . . . http://www.johnsoncontrols.com/content/us/en/products/power_solutions/Battery_Technology_Centers/lithium-ion_technology1/cells.html The other thing to remember is that GM has several irons in the fire in regards to battery vendors. LG makes the cells for the Volt and another company, Envia, is one that GM has invested in heavily in. They are poised to be a proverbial "next big thing" in regards to energy density . . . http://enviasystems.com/ http://www.businessweek.com/ap/2012-08-09/gm-may-have-electric-car-breakthrough Benjamin Nead Tucson, Arizona, USA Link to post Share on other sites
Greg_E 211 Posted October 17, 2012 Author Share Posted October 17, 2012 I'd like to see some overcharge, over discharge, and puncture tests on these soft pack cells. That was one of the advantages of the LiFe A123 cells is they were incredibly stable after damage, even the LG needs a little more work in that regard. Link to post Share on other sites
Benjamin Nead 1 Posted October 18, 2012 Share Posted October 18, 2012 Most lithium cells, Greg, can be damaged easily by overcharging and even by excessive discharging. Fortunately, the charging and controller circuitry found in modern electric cars prevents purposeful or accidental abuse in this regard. Such accidents there are almost non-existent. I fly model airplanes, where lithium batteries are now very common. Fires there are almost always a result of hobbyists who uses a multi-function charger and incorrectly dials up the wrong battery type (set it to charge a nickel metal hydride, for instance, instead of lithium.) These same sort of lithium cells are virtually identical to ones found in cell phones and portable computers. But almost everyone who owns those devices uses the dedicated charger sold with the device . . . and almost all these devices sold today are designed to stop functioning well before there is a danger of excessive undercharging the battery. Once these small lithium batteries outlive their usefulness and don't hold a charge any longer, they shouldn't be simply thrown in the trash. Take them to places like Ikea, Best Buy and Home Depot. These and other similar stores will responsibly recycle them. The puncturing of a lithium cell, though, can be catastrophic and a fire is almost always the end result . . . But auto designers are very careful to design multiple cell packs to be particularly immune form this sort of thing. Note the fire in a Nissan Leaf, reported below, was unrelated to the main pack and even though the fire destroyed the car, the main pack itself never caught fire . . . http://www.autoevolu...fire-48268.html The more alarmist elements of the media made much hay of Chevy Volt packs catching fire about this time last year. But these fires were a result of controlled collision tests to see if the pack fire COULD be an issue. Could a lithium fire occur on an EV? Sure. But also remember that approximately 185,000 gasoline vehicles catch fire in the U.S. every year. Please keep that in mind the next time there is some sensationalistic newspaper story or web article describing the danger of lithium battery EV fires. The lithium iron phosphate (LiFePO4) used by A123 and others is largely immune to fire. But, if punctured, they'll emit gases that nobody should be breathing. Any lithium battery with an aqueous electrolyte, in fact, is suspect here. Now, here's a small scale lithium battery that I recently became aware of that looks to be very safe. It features "solid state" construction and contains no liquid electrolyte. I was very impressed watching this video, noting what happened - or, more to the point, what DIDN'T happen - when the cell was purposely punctured and then immersed in water . . . Well, don't try anything in that above video with the lithium battery in your cell phone! This is a state-of-the-art battery and currently very expensive . . . about 30 to 40 times as expensive as a common lithium battery found today in a consumer electronic device or assembled into an EV pack. But this is for real and economies of scale will dictate that this sort of thing will be much more affordable someday. There has been much talk of future EV batteries being built into the exterior panels of the car itself. Don't worry about your EV of the future catching fire if someone bumps your fender in the grocery store parking lot. I'm confident this sort of technology will be available in our lifetimes. Benjamin Nead Tucson, Arizona, USA Link to post Share on other sites
Greg_E 211 Posted October 18, 2012 Author Share Posted October 18, 2012 The latest soft pack RC batteries contain a flame retardant chemical to help prevent fires when mistreated, there shouldn't be any packs sold that can cause flames when punctured. Hopefully Johnson Controls can keep things running and maybe make something out of their battery technology. Link to post Share on other sites
Benjamin Nead 1 Posted October 18, 2012 Share Posted October 18, 2012 Really? I hadn't heard about anything like that. There are flame retardent bags that you can put batteries into while charging, but I've never seen a battery with it built in. Could you post a link? Benjamin Nead Tucson, Arizona, USA Link to post Share on other sites
Greg_E 211 Posted October 18, 2012 Author Share Posted October 18, 2012 Links will be hard to come up with, but I know there are threads on RCGroups about it. Pretty much all the name brands have added this chemical to provide better safety, so there should be no more fires on a crash. I think a large amount of smoke is still released, but no open flames. I have not put this to the test but I know other people must have done this by now. Link to post Share on other sites
WyrTwister 0 Posted June 24, 2016 Share Posted June 24, 2016 I knew Johnson Controls was heavily into lead acid batteries . Guess they male other kinds ? God bless wyr Link to post Share on other sites
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