The Truth About Cars » battery life http://www.thetruthaboutcars.com The Truth About Cars is dedicated to providing candid, unbiased automobile reviews and the latest in auto industry news. Tue, 15 Apr 2014 02:57:23 +0000 en-US hourly 1 http://wordpress.org/?v=3.8.1 The Truth About Cars is dedicated to providing candid, unbiased automobile reviews and the latest in auto industry news. The Truth About Cars no The Truth About Cars editors@ttac.com editors@ttac.com (The Truth About Cars) 2006-2009 The Truth About Cars The Truth About Cars is dedicated to providing candid, unbiased automobile reviews and the latest in auto industry news. The Truth About Cars » battery life http://www.thetruthaboutcars.com/wp-content/themes/ttac-theme/images/logo.gif http://www.thetruthaboutcars.com Plug In America Tests Older Tesla Roadsters, Finds Battery Durability Better Than Promised http://www.thetruthaboutcars.com/2013/07/plug-in-america-tests-older-tesla-roadsters-finds-battery-durability-better-than-promised/ http://www.thetruthaboutcars.com/2013/07/plug-in-america-tests-older-tesla-roadsters-finds-battery-durability-better-than-promised/#comments Tue, 16 Jul 2013 13:30:43 +0000 http://www.thetruthaboutcars.com/?p=495371 Tesla Roadster battery pack - Tesla Photo

Tesla Roadster battery pack – Tesla Photo

One drawback to cars that run on batteries is that over time and multiple charge/discharge cycles, batteries will lose capacity. Individual cells start to fail to meet specifications and when enough cells go bad, it’s time for another battery pack. Since capacity is directly related to range and since battery packs are expensive to replace, how quickly batteries deteriorate is an important factor in the overall cost and practicality of EVs.

When Tesla first announced their Roadster EV in 2006, the company said that due the company’s proprietary battery management system and design of their lithium-iom battery packs, would ensure that after five years or 50,000 miles, the Roadster’s battery pack would still have 70 percent of it’s rated capacity when new, 53 kWh, enough electrons for a 244 mile range ( 2006 statement  on battery age by Tesla founder Martin Eberhard here). The Tesla Roadster went on sale in 2008, which means there are now roadsters that have been on the road for as long as five years, and I’m sure many that have reached or exceeded 50,000 miles of use. It’s now possible to test Tesla’s claims regarding battery durability. A standard from the laptop industry is that lithium-ion battery packs are still serviceable above 80% capacity.

The independent EV advocacy group, Plug In America (PIA) decided to do just that and their chief science officer, Tom Saxton has reported the results of an owner-reported survey of Tesla battery packs, based on a sample size of 4% of all 2,500 Roadsters made. Plug In America discovered that the Tesla battery packs are performing much better than advertised. After 100,000 miles, double the advertised 70% capacity life, the battery packs have an average capacity of 80-85%.

PIA also tested for climate differences because PIA’s earlier first ever  survey of EV battery life involving  owners of Nissan Leafs showed measurable declines in battery capacity in hot climates. The Leaf has a much simpler battery heat management system than used by Tesla. A surveys of first generation Toyota RAV4 EV owners, which was on sale from 1997 to 2003, in order to measure performance in batteries at least 10 years old, is also underway, as is a survey of Tesla Model S owners but it’s too early for any real meaningful data to be obtained on that car.

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Living With an EV for a Week – Day Six (Don’t honk at me, I’m saving the planet) http://www.thetruthaboutcars.com/2013/06/living-with-an-ev-for-a-week-day-six-dont-honk-at-me-im-saving-the-planet/ http://www.thetruthaboutcars.com/2013/06/living-with-an-ev-for-a-week-day-six-dont-honk-at-me-im-saving-the-planet/#comments Tue, 04 Jun 2013 22:07:45 +0000 http://www.thetruthaboutcars.com/?p=490709 Rainy forest, Picture Courtesy of Alex L. Dykes

Day six brought a typical Northern California morning: it was 41 degrees, foggy and raining in my forest. But because I was driving an electric vehicle, a squirrel greeted me at the doorstep to thank me for saving his home and a group of hummingbirds dried my charging cable with their tiny wings so I wouldn’t electrocute myself as I unplugged. Then I woke up. But it was still 41. And foggy. And raining.

If you’re just checking in, catch up by going to Day 1, Day 2, Day 3, Day 4, Day 5 before coming back to the saga, I promise we’ll wait for you.

Because I got up on time and I didn’t drive the orange Fiat 500e (Zippy Zappy) much on Sunday, I was greeted by a full charge. Via the smartphone app I commanded cabin heat since I had become soft and given into the temptation that is a warm cabin earlier in the week. Doing causes the cabin heater to turn on at a low-level to heat the cabin. It puts out as much heat as a regular-old space heater: not much. Given enough time it will get the cabin to a normal temperature. If your battery is already fully charged, using this feature will preserve range because you won’t use battery power to bring the interior bits up to temperature. This is not only in the name of battery life, but efficiency as well. It is more efficient to suck off the 120V/240V charging teat than to charge the battery and discharge it. Everything about the modern crop of EVs is designed around efficiency, even the sporty Model S. Increase efficiency and you reduce emissions.

Say what? How can you reduce emissions on a “zero emissions” vehicle? You thought EV equals zero emissions? Au contraire! Where do you think the power comes from? We’re all adults. We know by now the ATM doesn’t “make” money, and what powers our appliances has to be made somewhere. If that somewhere is in the United States, then on average half of it (49.6%) comes from coal. Average is an important thing to keep in mind, power sources vary wildly from zip code to zip code. If you’re in New York, rejoice because you have the cleanest power in the country as long as you’re in the camp that thinks nuclear power is clean. While not quite as squeaky clean as NY, California, the “Pacific Northwest” and New England are the cleanest places to power up your ride. If you live in Colorado or one of the other square states, your EV is a novelty coal-powered car. (Some portions of Colorado are nearly 75% coal.) Brings a new meaning to “clean coal” doesn’t it? In those coal heavy states, depending on which study you believe, driving a Nissan Leaf (one of the most efficient EVs) will produce similar greenhouse gas emissions to a 30MPG car. Ouch. If you live in Denver and drive an EV, you are making the forest sprites weep. Indeed, even the ginormous Toyota Avalon Hybrid (below) is 20% cleaner than your electric anything in The Centennial State. (And cheaper as well.)

2013 Toyota Avalon Limited, Exterior, Side, Picture Courtesy of Alex L. Dykes

 

What about the rest of us? Well, it is comforting to know that 32% of EVs are being sold in California with Florida at 6.6%, Washington 5.7%, Texas 4.3%, New York 3.5% (so much for those liberal Yankees being into left-wing propulsion and Texans loving oil.) Ohio, Illinois and North Caroline all come in at 3.1% with the other states trailing. That’s not surprising when you consider CA accounts for 11.1% of US car sales with others falling roughly in line: TX 9.6, FL 7.1, NY 5, IL 3.6. The stand out is the environmentally conscious Washington, third in EV sales but eighth in overall vehicle sales. If you want to check out where your power comes from, just click on over to the DOE’s nifty website. Or, for the reader’s digest MPG conversion, there is a very nifty map created by The Union of Concerned Scientists. The map below shows you the equivalent MPGs you would have to get in a gasoline car to be as clean as an EV that averages 0.34 kWh/mile. Zippy Zappy has been averaging only 0.25 kWh/mile, so adjust your figures accordingly. That model S? 0.38 kWh/mile.

Power MPG map, Picture Courtesy of www.ucsusa.org

The trouble with these numbers (aside from the fact that they are confusing) is: there is more going on than just greenhouse emissions. We have nitrous oxide (known as NOx because it refers to both NO and NO2) to think of. Upon closer inspection that seems to be a non issue because the average vehicle emits .001438 lbs of NOx per mile and a LEAF in Colorado (consuming 74% coal electricity, the worst in the USA) only puts out 0.0000096 lbs. Cross that one off your list. What about particulates? The claim is most forms of power generation produce less than the same energy in a gasoline vehicle. But what about the intangibles? How do you feel about hydro power and the effects on fish populations? Wind power and birds? Nuclear power and the insane people who think it’s going to make them grow 5 eyeballs? Think Solar power is your answer? If you charge at home off-peak (after 6pm for most of us) you’re in the dwindling return part of the day for solar in the summer, and in the dark in the winter. That means you may have put clean solar power into the grid, but at night you’re sucking down nuclear power and the other forms of generation that provide constant forms of output. (That’s as opposed to gas and others that can ramp up production quickly to meet spikes in demand.)

One must also consider the extraneous factors involved in the EV game. Recycling of the lithium-ion battery packs on the scale required is a current unknown. How about that EV charging station at home? How long will it last? How much of an environmental impact is buying an EV and not investing that money into home improvements to cut your utility expenses? How about buying local products and produce, etc.? I don’t have the answers to any of these questions, but I think they need to be resolved in my mind before I can say without a doubt that driving an EV is saving the planet.

2014 Fiat 500 Electric, Picture Courtesy of Alex L. Dykes

But on the other hand, does saving the planet have to be your EV goal? Is driving an EV because it reduces certain expenses and is exciting  technology enough? How about if your employer subsidises your EV charging in an attempt to be green? (Plenty do.) How about that HOV lane access? How about those crazy-cheap lease deals? I’m seriously considering an EV as my family’s next car purchase, but it has more to do with the financial and “time away from home” incentives than purely altruistic environmental concerns. Looking at that map above, if you feel truly inspired to protect the environment, then some of you will have to skip the EV holy grail and drive a 50+ MPG Prius C. Slowly.

My time with Zippy Zappy is drawing to an end. Tomorrow she will go back from whence she came to be primped and charged for the next journalist. With one final drive ahead of me in the morning, I oscillated between driving ZZ like I stole her and like the future of every forest creature depended on my frugality. I suspect I’m not alone with my personal struggles on the EV front. On the one hand an EV is an enormous gadget, perhaps the ultimate gadget. On the other, EVs don’t make a sound financial argument in terms of “saving” anything. The steep purchase price washes out much of the supposed savings vs a Prius. Being no closer to a conclusion, I plugged ZZ in one last time and noted my state of charge was 33% with an estimated time of completion 16 hours hence.

 

Looking for the other installments? Here you go:

Day 1

Day 2

Day 3

Day 4

Day 5

Day 7

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Piston Slap: Riddle Me This about Prius’ Batteries, Panther Love http://www.thetruthaboutcars.com/2012/09/piston-slap-riddle-me-this-about-prius-batteries-panther-love/ http://www.thetruthaboutcars.com/2012/09/piston-slap-riddle-me-this-about-prius-batteries-panther-love/#comments Wed, 05 Sep 2012 12:19:27 +0000 http://www.thetruthaboutcars.com/?p=458960

 

Lynn writes:

Hi Sajeev,

I enjoy your columns for their history and technology surprises of what might be wrong. Two history questions:

Since I have always been a penny pinching cheapskate and introvert I have never had an interest in large cars or silly awkward pick ups that burn lots of fuel and make lots of noise. Anyway, I don’t know what an auto Panther is or why several people at TTAC seem to remember it with fondness. Apparently the word has something to do with a frame built by Ford for many years but what is special about it and what is its history? Perhaps this could be worked in to one of your columns while helping someone with such a vehicle.

Many years ago I switched from Volkswagens to Toyotas and my life is now boring with no repair drama (or insults to my dignity from VW dealer staffs) and I haven’t been involved with auto repairs. A friend with a 2006 Prius with 90,000 miles asked me how long her car’s nickle metal hydride batteries would last out here in Phoenix’s hot sun. Any thoughts and history about this? Can the batteries be replaced with Lithium Iron Phosphate batteries?

Thank you,
Lynn E.

Sajeev answers:

Quite frankly, your life is boring to the point of shame.  And not because you can’t comprehend Panther Love, explained and defended here and a decent year-by-year analysis given here by yours truly. But because your life never included proper American Icon.

VWs and Toyotas are fine, but there’s more to automotive life. Especially in the American South, where we pride ourselves on our proper American rides, even if they are swanga’d customizations of some of the worst machines in General Motor’s history. But the Panther is an amalgamation of the best of Americana, it’s the right sauce for many people’s palette.

Put seriously, these cars have merit even if they will never be mainstream.  So if you don’t get it, don’t sweat it.  It’s all good.

About the friend’s Prius: because Hybrids have a temperature control system for their battery packs, Arizona’s heat isn’t as big of a deal compared to a normal battery under the hood of a steaming hot engine. I expect for Arizona heat to tax the system more than other regions, but this article does a good job putting it into context. Maybe one of the fixes and preventative maintenance suggestions in that article will significantly extend battery life. Or–as we used to say around here–not.

So let’s wrap it up: Toyota warranties these systems for 8 years or 100,000 miles.  Much like Hyundai’s insane warranties, I have little reason to doubt that Toyota did their homework.  Car companies don’t usually gamble with their cash flow in such a dangerous place. With any luck, your friend has a few years of life left…fingers crossed on that.

Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry.

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