Italian car makers Tazzari is promising the zero, a 113-inch long city car that is two and a half feet shorter than the Mini Cooper and slightly longer than the tiniest smidgen of a Smart car. It’s incredibly light at 1,200 pounds, and promises a range of 88 miles on a single charge, with a 56 MPH top speed.
That’s not great, but ample for a car mostly meant to be puttered around a metropolis. What’s stranger are the recharge numbers: Tazzari claims that the battery pack can be recharged up to 80% in fifty minutes, but that a full charge takes nine hours to complete. Note to Tazzari: “percent” means “portion of the whole.” Unless that last twenty percent only gives you an additional 18 miles of range, something’s a bit off.
It looks good, but not for the price: almost 20,000 euros, available in Europe only. That’s tens of thousands of euros more than what it costs to traverse most European cities by metro or bike… both of which, city driving being what it is, being probably speedier to boot.
Tazzari releases more details on Zero electric city car [Auto Blog Green]
Why does that recharge number seem off to you? Most modern battery chemistries get really touchy toward the end of a charge cycle and have to be charged gently and carefully to get the last few units of charge, while you can flog them pretty hard earlier in the cycle, when they are mostly empty.
The same behavior is seen in fast charge NIMH batteries, which can get to 70-90 percent in 15 minutes, then have to be trickle charged the rest of the way. Those little tiny toy cars that charge in 30 seconds or so from their remote controls are the same deal. They get away with crazy-high charge current by only filling the battery a little of the way.
Believe it or not the claims for charge time are not that outrageous. The reasons for it are beyond my ken, but I have often seen claims like this associated with battery packs. I think it is related to the fact that charging produces heat. You can fast charge a battery to a certain point but then you must back off to prevent the battery from exploding.
No. Those charge numbers sound right.
Li-Ion batteries start to overheat more readily once they reach ~80% of their full capacity, thus the need to charge them more slowly once they reach that threshold.
I don’t think their figures are wrong. Li-Ion batteries can only be charged at their maximum charge current for the initial part of the charge cycle, after that you need fancy charge circuits that can apply the right amount of current. I’m not an electro-chemist so I don’t know the reasons why. This is true of any Li-Ion battery, whether in a laptop or in an iPhone… next time you charge your phone, notice that it gets to about 80% in no time but takes a long while to top off.
Here’s a typical Lithium datasheet, see the
charging profile. Mostly charged by 1 hour,
several more hours to get the final 10% to go in.
http://www.saftbatteries.com/doc/Documents/liion/Cube752/7s2p_MP176065%20BLF_0208.f49954e0-f93b-449d-a84e-0c1f949591d2.pdf
I’d like to know the amerage rating of the required electric outlet to charge the car to 80% capacity in 50 minutes!
That’s obviously a huge leap forward for electric cars, though; if you can really get to 80% capacity that quickly then the car is a lot more practical.
I’m still not convinced. Could one more person chime in with the same information?
Thanks, that ought to do it ;p
I think the number sound off…
No really, but I do have a question that maybe a dozen or so people could answer.
So with a car this small, shouldn’t they list a range speed that varies depending on whether or not there is a passenger? I imagine and extra 150 pounds puts a fair amount of strain on the little engine.
Arkizzle: As I understand it, the nature of the batteries allows them to be charged rapidly part of the way, but then the charging has to slow down to prevent them from overheating and exploding.
If it’s hard to remember, there’s a helpful mnemonic I use for this:
“aiuitnotbattbcrpotwbttchtsdtoptfhae”
It’s the first letter of each word in the explanation, and coincidentally enough, it’s pronounced exactly like the call of the Austrian Toad Grackle, which is endangered for obvious reasons.
Hope this helps!
None of the 3 comments before mine were visible/posted when I posted mine… but anyway, I think that the charge time numbers are accurate because of the way batteries charge.
Zero electric?
So it’s 100% gas?