I won't challenge your ideas of Li ion cell life here, but there is new information. We have gone around that recently on the list.
Why Li ion batteries die. by Dr. Jeff Dahn https://www.youtube.com/watch?v=pxP0Cu00sZs Dahn says that cells don't have to die, and I believe him. Rickard (EVTV) thinks he proved that LFP cells have a shelf life (deteriorate a little just sitting).. I am not sure his estimates are definitive. For the original work on high precision coulometry: http://www.dal.ca/diff/dahn/publications.html Aaron Smith is now the engineer responsible for cell life at Tesla. Chris Burns is building and selling HPC test equipment. http://www.novonix.ca/ Linden's Handbook of Batteries - Chapter 26. *http://tinyurl.com/narq9nw <http://tinyurl.com/narq9nw>* Best regards, MIke On Wed, Mar 25, 2015 at 1:26 PM, Jamie K via EV <[email protected]> wrote: > On 3/25/15 10:11 AM, Michael Ross wrote: > >> Yes, the severe problem is in hot climates. So much of Europe is not >> going to see the issue. Though some may. Put a charged Leaf in a >> garage on a rock in Greece or Spain, let it heat up good in the summer >> sun and you will see some deterioration like in AZ. Unless they have >> made some improvements. >> > > Casual speculation aside, yes, they have made ongoing improvements to the > LEAF battery pack. It's worth reading this link: > > http://www.mynissanleaf.com/__viewtopic.php?f=4&t=17168&__ > hilit=+battery+update#p374490 > > Five year warranty on a pack is not really very good. If you get to 5 >> years, do they honor it further out to 60K? No, or they would just have >> a 60K warranty. So it is 5 years or less if one drives 60K. Here in the >> US 60k miles might use up $6000 in fuel on a similar size ICE car, less >> if the car is efficient. >> > > Here is Nissan's information on the battery warranty: > > http://nissannews.com/en-US/nissan/usa/releases/nissan- > announces-battery-replacement-program-for-leaf > > It's hard to predict what a gas car's fuel cost will be over the next five > years in the USA, but it's a fair guess that the price will remain volatile > and trend upwards, on average. Electricity prices are generally lower, less > volatile and costs generally go up more slowly. Some folks lock in a low > electric cost by installing solar panels. It also helps that electric cars > are more efficient than gas cars. > > > At ~60 miles to a charge, not much driving gets done, and a Leaf yields >> a poor payback against gas prices in the US if the battery pack makes >> trouble. If I had to buy a $5500 pack and some unknown labor every 5 >> years that would really suck. I expect cars to last 10+ years. >> >> According to my understanding of Li ion cells, it is possible to select >> cells, make packs and manage them for nearly unlimited life with no loss >> of capacity. You have to cool them, oversize them, undercharge them, and >> under discharge them. Not many EV manufacturers on that path yet. Here >> is hoping the new testing catches on and they all wise up. >> > > AFAIK there are two ways that lithium batteries deteriorate: > By use (cycles) and by calendar life. Managing charge levels and > temperature helps optimize battery life within those limits. I haven't > heard of an infinite life lithium battery, but maybe that will happen > someday. > > Meanwhile a roughly 24kWh battery at $6K or less for replacement (today's > cost) after 5-10 years (depending on how much range you need) is about $250 > per KWh, which is actually a market leading low price. The price could come > down further and/or the available capacity of the pack could go up by the > time a typical LEAF pack would need to be replaced. > > If ROI is your primary consideration when purchasing a car then you would > want to make a complete accounting, including all of the maintenance and > repair expenses over whatever you consider to be the car's useful life. > Plus fuel costs. > > I would put battery replacement in the maintenance/repair category. There > isn't much else in that category for the LEAF since it obviously doesn't > require a gas car's typical engine/transmission/fuel system/exhaust system > parts-fest. With regen, the LEAF doesn't even use the brake pads much. > > The LEAF is widely available today, has a decent feature set, and an > improved battery from at least 2013 forward. Electric vehicles offer > important advantages, so I'm glad it's available along with other choices. > It's the current best-selling BEV for a variety of reasons. Only you know > what works for you. > > Cheers, > -Jamie > > > SNIP >> >> -- To invent, you need a good imagination and a pile of junk. Thomas A. Edison <http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html> A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 585-6737 Land (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Google Phone (919) 631-1451 Cell [email protected] <[email protected]> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150325/02414a4e/attachment.htm> _______________________________________________ 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)
