Re: [EVDL] Cold Charging Lithium Experiences
I've heard this same thing but was not clear on how low of a rate. Does anyone know? Around C/10? Or lower? -ChrisChris' 1972 BMW 2002 | | | | | | | | | | | Chris' 1972 BMW 2002Owner Chris Darilek Location Austin, Texas US map Web WebPage Vehicle 1972 BMW 2002 Motor Advanced DC Series Wound DC Drivetrain 9 motor, standard ... | | | | View on evalbum.com | Preview by Yahoo | | | | | From: Michael Ross via EV ev@lists.evdl.org To: Danpatgal danpat...@yahoo.com; Electric Vehicle Discussion List ev@lists.evdl.org Sent: Friday, February 20, 2015 6:03 PM Subject: Re: [EVDL] Cold Charging Lithium Experiences I have seen some of the research on this - if you charge slowly you can avoid any plating. The issue is the electrolyte becomes vicious and the ions pile up on the SEI outside the cathode. What I saw said the problem was at -20C (-4F). But, I am not sure exactly what the cell construction was, and particularly the electrolyte composition. There are umpteen electrolyte recipes and they make a difference. One thin they do is use lower boiling point electrolytes to improve cold performance. If the cell is for a human implant you don't have to worry about it. Lot's of variety. I think you should heat the pack, and charge as slowly as you can just to be sure. Plating is really bad. Mike On Fri, Feb 20, 2015 at 3:25 PM, Danpatgal via EV ev@lists.evdl.org wrote: Reviving this thread as we're having another very cold stretch here in the Eastern US. My batteries (SE130 CALBs) are still going, but boy do they sag when it's cold like this. It's annoying. I've been charging when my BMS sensors (atop each cell) are over 0C, which they have generally remained over the past few weeks despite the cold (thankfully my garage generally stays above 0C). But, my follow-up question on all this is if the BMS measurement is good enough. For example, I guess there is resistive heat that gets generated upon charge/discharge/shunting that probably make the sensors read higher than the cells themselves. How much, I don't know. Does anybody have any thoughts, experience on this? We've gotten down to -20C with a HIGH today of only -10C ... yet I'm charging. I didn't really want to do it, but I was dragging so much on the road with low SOC%, I had to, or risk having to really limp home. - Dan Gallagher http://www.evalbum.com/3854 -- View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Cold-Charging-Lithium-Experiences-tp4667675p4673895.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) -- 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) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150220/5c77c4ea/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) -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150223/b83daa71/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)
Re: [EVDL] Cold Charging Lithium Experiences
Christopher, This is going to be different for every anode chemistry and electrolyte package. Now that reliable shorter time interval testing is possible, we may start to see better information like you are asking for. I think you are stuck with being careful and not really knowing. Heat your pack when charging below freezing - certainly, absolutely, below 0°F. YMMV. I would guess C/10 might be OK, based on nothing at all. Start pushing the people you buy cells from to get good testing done - or else you will buy from someone who does do it. That is the only way it happens. Mike On Mon, Feb 23, 2015 at 10:15 AM, Christopher Darilek via EV ev@lists.evdl.org wrote: I've heard this same thing but was not clear on how low of a rate. Does anyone know? Around C/10? Or lower? -ChrisChris' 1972 BMW 2002 | | | | | | | | | | | Chris' 1972 BMW 2002Owner Chris Darilek Location Austin, Texas US map Web WebPage Vehicle 1972 BMW 2002 Motor Advanced DC Series Wound DC Drivetrain 9 motor, standard ... | | | | View on evalbum.com | Preview by Yahoo | | | | | -- 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) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150223/297a8800/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)
Re: [EVDL] Cold Charging Lithium Experiences
http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150220/5c77c4ea/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) -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150223/b83daa71/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) -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150223/b1d6df51/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)
Re: [EVDL] Cold Charging Lithium Experiences
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[EVDL] EVLN: Tesla Roadster 3.0 update San Jose to LA w/o recharging
http://www.csmonitor.com/Business/In-Gear/2015/0217/Tesla-Roadster-3.0-update-San-Jose-to-LA-without-recharging Tesla Roadster 3.0 update: San Jose to LA without recharging By Stephen Edelstein, GreenCarReports February 17, 2015 [image / Issei Kato/Reuters/FIle http://images.csmonitor.com/csm/2015/02/0217roadster.JPG A Tesla Motors Roadster electric car drives in Tokyo in 2010. Telsa has confirmed an update of its first product, the Roadster 3.0, which has an extended range of between 40 and 50 percent. ] The Tesla Roadster has received its long-awaited update. A prototype of the Roadster 3.0 boosts the range of Tesla's very first product between 40 and 50 percent. Back in December, we first received confirmation of the 3.0 update for the Tesla Roadster, the electric-car maker's very first product, sold in the U.S. from 2008 through 2011. Tesla claimed the update would boost the Roadster's range 40 to 50 percent, and said a real-world demonstration was forthcoming. Now, that's been taken care of. A prototype Roadster 3.0 recently made the trip from San Jose, California, to the Santa Monica Pier in Los Angeles without stopping to recharge. That's a distance of approximately 340 miles, completed without any hiccups, according to a company blog post. While Tesla's original announcement of the Roadster 3.0 boasted that it could be driven over 400 miles per charge in certain conditions, this real-world test still showed a nearly 100-mile boost in range compared to the current car's 244 miles. Tesla also claims 20 miles worth of charge remained after completing the six-hour drive. The test trip started at the first Tesla Store in San Jose, and followed the I-5 to Santa Monica Pier, via a second Tesla Store on the 3rd Street Promenade. Cruise control was used on the highway sections of the route--set to stay right around the speed limit--and the heater was turned on for approximately 40 minutes, according to Tesla. The Roadster 3.0 upgrade consists of three major components. The first is a boost in battery-pack capacity from 53 kilowatt-hours to around 70-kWh, which will be accomplished using new battery cells with higher energy density. The second element is an aero kit that Tesla says will lower the coefficient of drag by about 15 percent from the current 0.31. Finally, the updated Roadster will be equipped with lower rolling resistance tires. Tesla previously said the coefficient of rolling resistance will be reduced from 11.0 kilograms per ton to 8.9 kg/ton. Tesla won't yet discuss pricing, availability, or the timing of the Roadster 3.0's launch. The company said it will apply lessons learned from the trip to continue development, meaning it could still be a while before customers can reinvigorate their Roadsters. [© The Christian Science Monitor] http://www.autoevolution.com/news/tesla-roadster-finishes-340-mile-trip-from-san-jose-to-la-on-a-single-charge-92371.html Tesla Roadster Finishes 340-Mile Trip From San Jose to L.A. on a Single Charge by Tudor Rus 17th February 2015 [image http://s1.cdn.autoevolution.com/images/news/tesla-roadster-finishes-340-mile-trip-from-san-jose-to-la-on-a-single-charge-92371_1.jpg ] If you’re moderately interested in Elon Musk’s work of making the world a better, greener and cleaner place by squeezing the immense potential of electricity, then you surely know Tesla loves road trips. Especially those that only require a single battery charge. But first, let’s meet the test subject, a prototype of the Tesla Roadster 3.0 upgrade. For those who arrived late at the party, the 3.0 update was specifically designed for the Roadster, Tesla’s first electric offspring. Announced in December, the Roadster 3.0 upgrade features consistent tweaks in battery cell technology, aerodynamics and rolling resistance. More precise, the battery pack capacity went from 53 kWh to about 70 kWh, an aero kit lowered the drag coefficient to just 0.31 and low resistance tires were installed on the updated Roadster. According to Tesla, these additional improvements will help the vehicle’s range bounce by 40 to 50%, to over 400 miles (644 kilometers). As good as this might sound in theory, we all know that real-life conditions will get the last word on this, right? Well, here’s the catch. Tesla set up a road trip which will help the electric-car maker in evaluating the package’s efficiency. In other words, the test prototype embarked on a 340-mile (547 kilometers) journey between the Tesla store in San Jose and the Santa Monica Pier in California. I think you already guessed the outcome of the journey, but that won’t hold us back from telling you that the trip was smooth ride, without interruptions. Finally, the Tesla Roadster 3.0 prototype needed less than six hours to reach its final destination, with 20 miles remaining in the battery pack. Despite being a bit far-fetched from Tesla’s aforementioned improved range, the real-world test showed a visible improvement - by
[EVDL] EVLN: Tesla, Google, Apple Silicon Valley= the home of future cars
Apple's Titan/iCar EV could be in production by 2020 http://www.themalaymailonline.com/drive/article/tesla-google-apple-silicon-valley-emerges-as-home-of-electric-cars Tesla, Google, Apple — Silicon Valley emerges as home of future cars February 22, 2015 [image http://media.themalaymailonline.com/images/sized/ez/drive_20150115_Google_self-driving_car_840_559_100.jpg ] File picture shows a Google self-driving vehicle parked at the Computer History Museum after a presentation in Mountain View, California. — Reuters pic NEW YORK, Feb 22 — Is the future of the US car industry in Silicon Valley? After Tesla and Google, Apple appears to be readying for a plunge into the industry long rooted far away in the steel belt of the US upper Midwest. According to various media reports, the maker of iPhones and iPads has created a special unit baptised “Titan” with hundreds of staff to begin developing an electric car, with 2020 the target date. Apple remains silent on the project, but the reports were partially backed up by a lawsuit filed against the tech giant. Battery maker 123 Systems has accused Apple of aggressively poaching its staff. But it puts Apple in line with Tesla, the current champion of the electric car, and Google, the online giant that is focused on the self-driving, also-electric Google Car. The Big Three US automakers — General Motors, Ford and Chrysler (now a part of Fiat Chrysler Automobiles, FCA) — are taking the threat from the Detroit outsiders seriously. “Given the company’s (Apple’s) tremendous capabilities, that is no surprise to anyone,” GM spokesman Dan Flores told AFP. At Chrysler, spokesman Eric Maynes said: “We can’t comment on something we haven’t seen.” Ford too had no comment on Apple’s plans, but the number two automaker recently opened a research centre in Palo Alto, the heart of Silicon Valley, as it looks to the future of self-driving automobiles. Bill Visnic, an analyst at industry specialist Edmunds.com, said that given the seven-year average time frame to develop and bring a car to the mass market, the Detroit giants are not under serious pressure yet. Even with the unexpected success of Tesla, for instance, the company still sold less than 35,000 cars last year in an national market of more than 16 million units. And Tesla’s cars are confined to a very high-end niche market. “Apple is not an immediate threat to the US auto industry. I don’t think you’ll see the volume there, the number of cars won’t really begin to approach anything like Detroit is making right now at any time soon,” said Visnic. Alec Gutierrez, a market analyst at Kelley Blue Book, said Apple’s strength is its role as a “disruptor” in industries, and that the “comprehensive ecosystem” of its popular consumer electronics could be extended to an “Apple car”. Money to spend Apple has the money to put into a new car — some US$180 billion (RM660 billion) in capital built up to invest in new projects. Even so, said Gutierrez, given the costs and competition in the auto industry, “it’s fraught with risk.” “The automotive space is so highly competitive today, and margins in new car sales are extraordinarily thin, which is something Apple is not used to.” “How many companies have totally failed into trying to enter the automotive industry? It’s a tough thing and it’s very expensive,” added Brett Smith, program director at the Center for Automotive Research. He pointed to Tesla continuing to lose money despite its success in marketing its luxury cars with battery systems superior to any offered by Detroit. And the major automakers are all working hard on making more and better hybrid and all-electric vehicles. That sets a high bar for any new entrant, notes Smith. “Does Apple have better technologies than Mercedes or Ford or GM or Toyota to build a car? I really doubt it.” What Apple could bring to the industry is what Google brings: ways to process and use data. Google is focused not on the physical car itself but on the technology that will allow cars to run themselves. Its self-driving vehicles, in the guise of various car models, have already driven hundreds of thousands of miles on California roads in test runs. Apple already has something to offer the industry, notes Visnic. It could become a key supplier of connectivity technology for cars, putting its operating systems up against Google’s Android, already being installed in many car models. “For Apple, they have proven to be phenomenally good at user experience,” Smith told AFP. “The car for them will become another user experience device, and that will differentiate them.” — AFP [© themalaymailonline.com] ... http://auto.economictimes.indiatimes.com/news/industry/google-apple-is-silicon-valley-the-future-of-car-industry/46340694 Google, Apple: Is Silicon Valley the future of car industry? AP | 23 February 2015 After Tesla and Google, Apple appears to be readying for a plunge into the industry long
Re: [EVDL] Cold Charging Lithium Experiences
Does the data presented apply to Li-Fe-PO4 or only to Li-Ion metal oxide? I know that they have a distinctly different chemistry than metal oxide cells, and I know that they have different charging characteristics. It is likely they have different cold weather charging behavior as well. I looked up a few references on the web and you seem to be able to charge LiFePO4 cells down to -10 C quite normally with no caution mentioned about going to lower temperatures. An example is Powerstream Batteries http://www.powerstream.com/LLLF.htm show in their specifications charge down to -40 C. The A123 cells spec sheet show a temperature range of 55 to -30 C. I don't see any reference to lithium plating out or anything drastic when I restrict my search to LiFePO4. ( I also ignored blogs and forums. I just looked up papers and manufacturer specs.) I think that cold weather effect may be restricted to lithium-ion metal oxide cells. That reflects my personal experience with a pack of LiFePO4 ThunderSky cells in freezing Colorado weather with outdoor storage. The vehicle took a few miles to warm up the pack, and range suffered a bit because of voltage sag due to cold weather, but that was about the extent of it. I think it is important to not group all Li-ion in the same basket. The LiFePO4 cells share a few of the characteristics with metal-oxide cells, but are quite distinct in many ways. Also, there are a great variety of metal oxide li-ion cells, which are distinct from each other. Bill Dube' On 2/23/2015 5:19 PM, Michael Ross via EV wrote: Discharging pulls lithium off of the cathode side SEI (solid electrolyte interface) if it has been plated there, but according to the electrochemists other bad stuff goes on so the capacity lost to plating the cathode is not reversible even if the plating itself is reversible. I wish I understood this better, but the science of it may be uncertain beyond knowing that it is bad. So when you charge, the ions move towards the cathode, and when it is cold the motion into the cathode is too slow and the lithium piles up on the SEI as a metallic lithium - it is plated. When you discharge the metallic lithium diffuses into the electrolyte and the motion of ions is towards the anode. I am not aware that discharging is a problem, I have seen nothing in the literature about it; and high currents will generate heat right where the action is. On Mon, Feb 23, 2015 at 2:11 PM, Rick Beebe via EV ev@lists.evdl.org wrote: That was one of my big concerns when I built my truck so I tried to fix it from the beginning. I put 1 of foam insulation in all my battery boxes. I installed battery warmers under the batteries. I used 35 watt Farnum heaters I got from KTA-EV. And I built a controller to turn the heaters on below 15C and to disable charging below 3C. All of that runs only when the truck is plugged in. I've been leaving the truck plugged in at home and it's keeping the batteries at 15C (60F) despite temps to -20C. CALB allows the cells to be discharged at a much lower temperature than charging so I'm less worried about the cells cooling off with the truck unplugged at work. That said, the insulation really helps slow down that process. I've found that on a 20F day the cells have dropped to about 45F after 8 hours at work. The other advantage to the cells being warmer, of course, is much better performance. My understanding is that temperature of the anode is the critical piece. I don't know if your BMS is measuring that or simply the air above the cell. --Rick On 02/20/2015 03:25 PM, Danpatgal via EV wrote: Reviving this thread as we're having another very cold stretch here in the Eastern US. My batteries (SE130 CALBs) are still going, but boy do they sag when it's cold like this. It's annoying. I've been charging when my BMS sensors (atop each cell) are over 0C, which they have generally remained over the past few weeks despite the cold (thankfully my garage generally stays above 0C). But, my follow-up question on all this is if the BMS measurement is good enough. For example, I guess there is resistive heat that gets generated upon charge/discharge/shunting that probably make the sensors read higher than the cells themselves. How much, I don't know. Does anybody have any thoughts, experience on this? We've gotten down to -20C with a HIGH today of only -10C ... yet I'm charging. I didn't really want to do it, but I was dragging so much on the road with low SOC%, I had to, or risk having to really limp home. ___ 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) -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150223/6652c485/attachment.htm
Re: [EVDL] Cold Charging Lithium Experiences
Discharging pulls lithium off of the cathode side SEI (solid electrolyte interface) if it has been plated there, but according to the electrochemists other bad stuff goes on so the capacity lost to plating the cathode is not reversible even if the plating itself is reversible. I wish I understood this better, but the science of it may be uncertain beyond knowing that it is bad. So when you charge, the ions move towards the cathode, and when it is cold the motion into the cathode is too slow and the lithium piles up on the SEI as a metallic lithium - it is plated. When you discharge the metallic lithium diffuses into the electrolyte and the motion of ions is towards the anode. I am not aware that discharging is a problem, I have seen nothing in the literature about it; and high currents will generate heat right where the action is. On Mon, Feb 23, 2015 at 2:11 PM, Rick Beebe via EV ev@lists.evdl.org wrote: That was one of my big concerns when I built my truck so I tried to fix it from the beginning. I put 1 of foam insulation in all my battery boxes. I installed battery warmers under the batteries. I used 35 watt Farnum heaters I got from KTA-EV. And I built a controller to turn the heaters on below 15C and to disable charging below 3C. All of that runs only when the truck is plugged in. I've been leaving the truck plugged in at home and it's keeping the batteries at 15C (60F) despite temps to -20C. CALB allows the cells to be discharged at a much lower temperature than charging so I'm less worried about the cells cooling off with the truck unplugged at work. That said, the insulation really helps slow down that process. I've found that on a 20F day the cells have dropped to about 45F after 8 hours at work. The other advantage to the cells being warmer, of course, is much better performance. My understanding is that temperature of the anode is the critical piece. I don't know if your BMS is measuring that or simply the air above the cell. --Rick On 02/20/2015 03:25 PM, Danpatgal via EV wrote: Reviving this thread as we're having another very cold stretch here in the Eastern US. My batteries (SE130 CALBs) are still going, but boy do they sag when it's cold like this. It's annoying. I've been charging when my BMS sensors (atop each cell) are over 0C, which they have generally remained over the past few weeks despite the cold (thankfully my garage generally stays above 0C). But, my follow-up question on all this is if the BMS measurement is good enough. For example, I guess there is resistive heat that gets generated upon charge/discharge/shunting that probably make the sensors read higher than the cells themselves. How much, I don't know. Does anybody have any thoughts, experience on this? We've gotten down to -20C with a HIGH today of only -10C ... yet I'm charging. I didn't really want to do it, but I was dragging so much on the road with low SOC%, I had to, or risk having to really limp home. ___ 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) -- 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) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150223/52534a0f/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)
Re: [EVDL] Cold Charging Lithium Experiences
This is a sobering thread. For all the conviction I hear that lithium is the only way forward, winter is when it's clear that NiMH and NiCd - maybe even lead - batteries are still far from obsolete. I know, that's why battery thermal management exists, but still - if you can't charge your EV's battery when it's below freezing temperature - below FREEZING, not below zero F - that's kind of unsettling. In a usability sense, maybe lithium batteries aren't so different from Diesel fuel, which tends to turn to gel in extremely cold weather. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to evpost and etpost addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ 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)
Re: [EVDL] Cold Charging Lithium Experiences
Dave, You can charge when it is cold, you just can't do it as fast. Or you have to put some heat to the pack - which apparently is not a new idea to many. The typical routine - come from work, hook it up so it is ready in the AM, is likely to be slow enough. But, we now know that we don't know any of this exactly - it is dependent on the type of Li ion cells and the electrolyte package in them. The only way that is known well, is using the high precision coulometry testing methods, and that is pretty new and not wide spread knowledge. You can get a taste of this from the video I have linked to (although he never discusses cold charging at all). It is obvious that Tesla can make this work. If some DIY EV people wanted to pool resources and get testing done, then Novonix could help sort this out, or point in the direction of people with the new life testing equipment. Until that happens, we will be dependent on suppliers to do it, believing - blindly it seems - their specifications, or anecdotal evidence. You can read the papers that have been published, but research seems to address different problems than what concerns the DIY EV'er. You will have to intuit from tests of other cells what to do with your own - and you probably don't really know what your own cells are made from. One of the things in Dr. Dahn's video is a hint at how important the electrolyte package is. Just small amount of an additive can make a hude difference in cell life under different conditions. NiMH and NiCAD have their own issues. On Mon, Feb 23, 2015 at 10:48 PM, EVDL Administrator via EV ev@lists.evdl.org wrote: This is a sobering thread. For all the conviction I hear that lithium is the only way forward, winter is when it's clear that NiMH and NiCd - maybe even lead - batteries are still far from obsolete. I know, that's why battery thermal management exists, but still - if you can't charge your EV's battery when it's below freezing temperature - below FREEZING, not below zero F - that's kind of unsettling. In a usability sense, maybe lithium batteries aren't so different from Diesel fuel, which tends to turn to gel in extremely cold weather. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to evpost and etpost addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ 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) -- 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) 550-2430 Land (919) 576-0824 https://www.google.com/voice/b/0?pli=1#phones Google Phone (919) 631-1451 Cell michael.e.r...@gmail.com michael.e.r...@gmail.com -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150224/2384af62/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)
