# Why can't we swap out electric vehicle batteries? **URL:** \ **Category:** Factual Questions\ **Created:** [June 4, 2011, 4:28pm UTC](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314 "2011-06-04T16:28:26Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [June 5, 2011, 3:29pm UTC](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314/21 "2011-06-05T15:29:59Z")
**dtilque** , while the technology to DC charge that fast [exists](http://reviews.cnet.com/8301-13746_7-20011094-48.html) it is not the agreed standard or one that is under much consideration. > [@](#): > > “You can do it, but you will melt every wire that manufacturers use,” said Mark Perry, Nissan director of product planning, “There is a DC fast charger that exists and manufacturers have agreed to.” … Using Chademo compliant level 3 chargers, the Leaf can charge an empty battery up to 80 percent in 30 minutes. A battery only half empty can reach the 80 percent capacity in about 15 minutes. > That’s a lot faster than the 12-15 mile range you get per hour of charging a Leaf using level 2 chargers, but it’s not as fast as filling up a car with gas. But for the foreseeable future, it’s as good as it’s going to get. > “When you charge at five times the rate, you get 25 times the heating,” explained Gow. And heat is the enemy of lithium ion batteries. The Better Place model OTOH can have a vehicle leaving in less time than a gas fill-up. Again, I’m not sure how important that wil end up being. **kanicbird** , Under that model the battery pack is not theirs, it merely is the means of delivering the fuel. They pay much less for the car as they are not paying for the battery. The cost of batteries is built into the charge for delivering the electricity instead and Better Place delivers the electricity. They have no worry of the pack wearing out … ever. Better Place instead keeps up to date with keeping fully functional batteries and upgrading as better battery technology comes along. And as for the radio stations … really? You don’t think that these cars would be made in a way to preserve the stations? ---
**Author:** ![UltraVires](https://avatars.discourse-cdn.com/v4/letter/u/ecccb3/32.png) [@UltraVires](https://boards.straightdope.com/u/UltraVires)\ **Post date:** [June 5, 2011, 4:05pm UTC](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314/22 "2011-06-05T16:05:58Z")
> [@Chronos](#): > > And the long charging time isn’t a problem, anyway. Charge it overnight (when electricity is cheaper anyway), and you’ve got everyone covered whose round-trip commute is within the car’s range. If businesses start to put in charging stations as an employee perk, then you’ve got everyone whose one-way commute is within range. And for going on a hundreds of miles trip to Gramma’s house, you just use the other car that, as an American family, you probably have anyway. Or make it a plug-in hybrid instead of a pure electric, and just fill up at the gas station like you do now for those trips (while still doing most of your commuting on battery). But any savings I might get would be in that 100 mile trip to Grandma’s. If we are just talking about a 6 mile commute to work, why wouldn’t I want to keep my gas car, even if it was $7 or 8 per gallon? What if I want to go to lunch? Can’t, car is recharging. What if the family wants to go out to dinner? Can’t car is recharging. What if there is an emergency in the middle of the night? Car is recharging. I would guess that your answer to those would be to just use the other gasoline car, but if that’s the case, then what’s the point of paying many tens if not hundreds of thousands of dollars for the electric car if it is just a souped up golf cart? ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [June 5, 2011, 4:13pm UTC](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314/23 "2011-06-05T16:13:37Z")
> [@Bryan\_Ekers](#): > > It’d be easier to swap cars. Just park, plug into a recharging station, drive off with a different fully-charged vehicle… An electrical variation on [Zipcar](http://en.wikipedia.org/wiki/Zipcar)? ---
**Author:** ![Snnipe\_70E](https://avatars.discourse-cdn.com/v4/letter/s/b5a626/32.png) [@Snnipe\_70E](https://boards.straightdope.com/u/Snnipe_70E)\ **Post date:** [June 5, 2011, 4:25pm UTC](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314/24 "2011-06-05T16:25:29Z")
> [@Bryan\_Ekers](#): > > It’d be easier to swap cars. Just park, plug into a recharging station, drive off with a different fully-charged vehicle… Ithink this makes more seice that sswapping batteries.😃 ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [June 5, 2011, 6:11pm UTC](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314/25 "2011-06-05T18:11:12Z")
> [@jtgain](#): > > But any savings I might get would be in that 100 mile trip to Grandma’s. If we are just talking about a 6 mile commute to work, why wouldn’t I want to keep my gas car, even if it was $7 or 8 per gallon? [This is why.](http://boards.straightdope.com/sdmb/showpost.php?p=13697749&postcount=89) The savings is in the usual miles people drive in a usual year. > [@me](#): > > Nissan Leaf gets roughly 100 miles per recharge (depending on driving habits) and uses up about 16kW in the process. Assume 12,000 miles per year. That’s 1920kW/year. Let’s assume that electricity stays fairly constant at $0.10/kW so that’s $192/y for the electricity. > > The comparable Sentra runs about maybe 450 gallons for the same year. Let’s use that. > > Let’s use the 5 year average ownership of a new car and assume the same depreciation per vehicle. Don’t forget that the ICE needs service (oil and transmission fluid changes brake pads, etc) that the pure BEV does not. We’ll ignore the value of your time, just count about $400 a year ballpark. Heck, lowball it to $300. Over 5 years $1500. Tires and others stuff they both have so we will ignore those ongoing costs. Ignore externalized costs, like energy dependence and GHG emissions. > > What combinations of decreased battery cost and increased gas costs put the EV ahead? > > 450 gallons at $3/g =$1350/y. 5 years comes to $6750. Total $8250 running costs. > at $4/g = $1800/y. 5 years comes to $9000. Total $10,500 running costs. > at 5/g = 2250/y. 5 years comes to $11,250. Total $12,750 running costs. > > The Leaf over the 5 years is $192/y. 5 year running costs $960. > > So the premium for the battery can be $7290 at $3/g, $9540 at $4/g, and $11,790 at $5/g. > > Currently the difference between the two vehicles is about $12,800 without the tax credit and $5,300 with it. > > So for the consumer, who gets a tax credit, it pays to buy the Leaf today over the comparable ICE even at $3/g gas and at $4/g gas they’ll save over $4000. Yes the cost of the vehicle with battery needs to drop down some more, along with gas prices staying this high or higher, for it to make sense without any tax credit, but realistically by the time the credits are gone both of those are very likely to have occurred. > [@jtgain](#): > > What if I want to go to lunch? Can’t, car is recharging. > What if the family wants to go out to dinner? Can’t car is recharging. > What if there is an emergency in the middle of the night? Car is recharging. Unplug the car and go to lunch. Go to dinner. Take car of the emergency. You think it needs to finish topping it off before you can use it once you plug it in? What pure EVs are not good for is the cross country trip. Rapid charge even would force a leisurely drive with longer more frequent stops than many would want to make. (Even though [some corridors](http://green.autoblog.com/2011/06/03/aerovironment-to-install-quick-charge-stations-along-oregons-i/) [will have that in place soon](http://green.autoblog.com/2010/12/01/cracker-barrel-to-install-high-speed-plug-in-vehicle-charging-st/)). And it is [possible.](http://green.autoblog.com/2011/06/02/video-dutch-duo-drives-nissan-leaf-779-2-miles-in-24-hours/) Placing Better Place swap stations across the interstates seems unlikely. It is better suited for places that function as “islands”, like Israel or a major metropolitan area. And for fleets that put on many many miles and want to keep going. A taxi for example that puts on 100K a year, something like 275 miles a day, rolls in and out of a swap station maybe three times a day and keeps going, saving a ton on fuel and maintenance costs in the process. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [June 5, 2011, 7:19pm UTC](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314/26 "2011-06-05T19:19:46Z")
> [@DSeid](#): > > **kanicbird** , Under that model the battery pack is not theirs, it merely is the means of delivering the fuel. They pay much less for the car as they are not paying for the battery. This model has been suggested as a workable option. Another one I heard about many years ago was to replace the anode only, or was it the cathode, anyway the battery was made with aluminum that would be the sacrificial part, the aluminum would eat away itself in the reaction, I think I’ve heard it can be recycled and reused but not sure. The battery was basically a non-rechargeable design, so no home recharging, you needed to replace the plates, and aluminum plates are far lighter then batteries. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 5, 2011, 7:51pm UTC](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314/27 "2011-06-05T19:51:34Z")
**DSeid** , you keep referring to energies in kW in that post. I presume you mean kWh? A kilowatt is a unit of power, not energy. ---
**Author:** ![Jamicat](https://avatars.discourse-cdn.com/v4/letter/j/c67d28/32.png) [@Jamicat](https://boards.straightdope.com/u/Jamicat)\ **Post date:** [June 5, 2011, 8:28pm UTC](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314/28 "2011-06-05T20:28:54Z")
Best Idea for this would be to standardize the placement and size of batterypack. Most likely accessed from the undercarriage… I vision a jiffy lube/automated car wash type hybrid setup. Pull in over the machine, machine cleans dirt off retainers, machine decouples old battery, installs new fully charged one, pay n go. Might need an attendant for special circumstances. But, otherwise all automated. All that is needed for batteries is clamping mechanism and positive contact points, just like a cell phone or battery operated tools. 🙂 (edit) The machine charges the batteries on site, and of course they all have chips and an on board computer to keep track of details. ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [June 5, 2011, 8:55pm UTC](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314/29 "2011-06-05T20:55:44Z")
That is precisely what the Better Place stations do. Incidentally, the clamping mechanism used for the batteries is basically the same mechanism used on fighter jets to attach the missiles. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [June 5, 2011, 9:16pm UTC](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314/30 "2011-06-05T21:16:35Z")
> [@Chronos](#): > > **DSeid** , you keep referring to energies in kW in that post. I presume you mean kWh? A kilowatt is a unit of power, not energy. Yes. Sorry. ---
**Author:** ![Jragon](https://avatars.discourse-cdn.com/v4/letter/j/e19b73/32.png) [@Jragon](https://boards.straightdope.com/u/Jragon)\ **Post date:** [June 5, 2011, 10:04pm UTC](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314/31 "2011-06-05T22:04:21Z")
So say we do this, do we actually produce enough electricity to be recharging all of these batteries (wherever it may be done). I assume so, because I never see anybody talking about it, but does our current electrical output even support the sheer amount of extra work this would take (assuming everyone magically switched to driving electric with this battery swap model). ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [June 5, 2011, 11:37pm UTC](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314/32 "2011-06-05T23:37:49Z")
Yes, we already have enough capacity at off-peak times to fuel converting 80% of the light duty fleet per some expert calculations. (Although our own energy expert on this board thinks such is somewhat overestimated by them.) ---
**Author:** ![UncleFred](https://avatars.discourse-cdn.com/v4/letter/u/f0a364/32.png) [@UncleFred](https://boards.straightdope.com/u/UncleFred)\ **Post date:** [June 6, 2011, 1:46am UTC](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314/33 "2011-06-06T01:46:01Z")
What would be the electric service provided to such a service station? How many KW? If one ‘charge’ is 16KW as in the Nissan example, and let’s say the station has to recharge 500 cars over an 8-hour night-period. 1. that’s a loit of space to store those batteries 2. I make it that’s a 1 megawatt supply, or ballpark 2K amps at 480V That was a crappy, quick calculation but I’m getting the feeling that’s far more power than even a small commercial building gets - we’re talking maybe a small substation. Maybe 100 cars is a better estimate, and maybe they can ‘rotate’ the charging over the full 24 hours, but the numbers are still kinda big. ---
**Author:** ![UncleFred](https://avatars.discourse-cdn.com/v4/letter/u/f0a364/32.png) [@UncleFred](https://boards.straightdope.com/u/UncleFred)\ **Post date:** [June 6, 2011, 2:08am UTC](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314/34 "2011-06-06T02:08:38Z")
> [@UncleFred](#): > > If one ‘charge’ is 16KW as in the Nissan example, and let’s say the station has to recharge 500 cars over an 8-hour night-period. That’s 16 KWH ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [June 6, 2011, 7:07am UTC](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314/35 "2011-06-06T07:07:22Z")
They’ll probably also have large centralized backup charging centers, which will be able to send charged batteries to stations that are running short. ---
**Author:** ![SunSandSuffering](https://avatars.discourse-cdn.com/v4/letter/s/ee7513/32.png) [@SunSandSuffering](https://boards.straightdope.com/u/SunSandSuffering)\ **Post date:** [June 6, 2011, 2:01pm UTC](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314/36 "2011-06-06T14:01:34Z")
Sounds like the sort of thing people used to do with radio batteries pre-WW2. ---
**Author:** ![Cheesesteak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cheesesteak/32/3694_2.png) [@Cheesesteak](https://boards.straightdope.com/u/Cheesesteak)\ **Post date:** [June 6, 2011, 2:55pm UTC](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314/37 "2011-06-06T14:55:48Z")
Today, electric car batteries are: Large Heavy Expensive High technology Easily rechargeable at home Problem #1, you need a machine to get under the car and move the large, heavy batteries. Problem #2, you need a large stock of expensive fully charged batteries ready to install, and stored conveniently for immediate use Problem #3, you need manufacturers to standardize technology that they currently use to differentiate themselves in the market Problem #4, you need manufacturers to build their cars around your batteries Problem #5, you need to convince consumers to give you their brand new, expensive batteries in trade for used batteries Problem #6, people can and will regularly recharge their batteries at home, giving them enough range to handle their daily trips without needing to swap batteries at all\*. When they do need to swap, it will be when they are planning a longer than normal trip, like on weekends at which point your stations will be swamped after being empty all week. By the time batteries become small enough, light enough, cheap enough and standard enough to be swappable, you’ll have a range long enough to practically eliminate the need for road side recharging. - I find it unlikely that the typical person would eagerly buy a car that they would have to fill up with gas (or swap batteries) every single day, unless there were no other alternative. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [June 6, 2011, 3:13pm UTC](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314/38 "2011-06-06T15:13:22Z")
> [@Tim\_R.Mortiss](#): > > I don’t think the big problem is with non-interchangeability, or with the handling of heavy, bulky batteries. The first problem can be solved with appropriate industry standards, which has been accomplished in every other industry. And the second can be solved with appropriate vehicle and swap-station designs (make them modular, put them at the very back of the vehicle, etc.). Placing several hundred pounds at the rear of an already light vehicle would render it uncontrollable at speed. Stranger ---
**Author:** ![constanze](https://avatars.discourse-cdn.com/v4/letter/c/f9ae1b/32.png) [@constanze](https://boards.straightdope.com/u/constanze)\ **Post date:** [June 6, 2011, 3:26pm UTC](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314/39 "2011-06-06T15:26:28Z")
> [@DrCube](#): > > I’m always hearing about how we need a vast new infrastructure to cope with a societal switch to electric vehicles, supposedly to charge batteries during trips like we “recharge” our gas tanks currently. > > But, for example, I can bring an empty propane tank to the store and swap it out for a full one, while all the refilling goes on behind the scenes and whatever pace works for the propane fillers. Why couldn’t gas stations just stock up on batteries and swap them out when they get low? This doesn’t seem to require a brand new infrastructure to me, or even state of the art quick charging batteries. We could get it up and running as soon as the cars existed. I understand the energy currently powering oil refineries will have to be redirected to this battery industry. But that seems like something that will naturally occur as we shift towards electrics. > > So, where am I wrong? What am I missing when I hear about how expensive the infrastructure will be for electric vehicles? This is one of the different schemes being debated. The main problem currently is that most electric-only cars today are prototypes of some kind or other, and that each car company is using their own different, unique, akku battery make and model. This is complicated by the fact that the makers of akku batteries themselves are having a race trying to develop better, longer, cheaper, lighter akkus. This means instead of swapping one empty standarized propane bottle for a full standarized bottle, you had 15 to 20 different sizes with different pressures. Or how the akku batteries in cell phones and video cameras and laptops all have different voltage and shape and can’t be swapped. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [June 6, 2011, 4:10pm UTC](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314/40 "2011-06-06T16:10:06Z")
What does “akku” mean in this context? [Previous page](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314.md?page=1) [Next page](https://boards.straightdope.com/t/why-cant-we-swap-out-electric-vehicle-batteries/584314.md?page=3)