QA：如果一辆电动汽车在行驶中没电了会发生什么？
What happens if an electric car runs out of charge while driving?
译文简介
网友：这是一个可笑的过于简化的问题，电动车的反对者很喜欢这个问题。答案是你需要一辆拖车把你送到离你最近的充电站那里。然而：这忽略了一点，那就是你必须是一个非常愚蠢的人，才会陷入这种境地......
正文翻译
What happens if an electric car runs out of charge while driving?
如果一辆电动汽车在行驶中没电了会发生什么？
评论翻译
很赞 ( 4 )
收藏
This is one of those ridiculously over-simplified questions beloved of EV haters.
The answer is that you’ll need a tow truck to get you to the nearest charger.
HOWEVER: What this misses is that you have to be an INCREDIBLY STUPID PERSON to get in that situation in the first place.
In my car (Tesla Model 3) - the car’s nav system knows where all of the chargers are. On trips long enough to need mid-journey charging, the car will plan the route with the optimum number of chargers along the way.
If you miss a charging station, the car will warn you if you are about to get further beyond the charger than you can reach.
It will also start to suggest measures such as driving more slowly and reducing the A/C or heat to stretch your range.
这是一个可笑的过于简化的问题，电动车的反对者很喜欢这个问题。
答案是你需要一辆拖车把你送到离你最近的充电站那里。
然而：这忽略了一点，那就是你必须是一个非常愚蠢的人，才会陷入这种境地。
在我的汽车（特斯拉Model 3）中，汽车的导航系统知道所有充电站的位置。如果行程足够长，需要中途充电，汽车会在沿途规划最佳充电站数量的路线。
如果你错过了一个充电站，如果你即将超出充电站的范围，汽车会警告你。
它还会开始建议采取措施，如放慢驾驶速度，减少空调制冷或者制热，以增加您的行驶里程。
Teslas, yes. It would have been easier for me to run out of range with my little Chevy Spark EV, although it would have given me warnings, and constantly displayed the remaining range. It didn’t know where the charging stations were; I had to know that (in apps in my phone).
特斯拉，是的。对我来说，用我的雪佛兰Spark电动汽车跑完全程会更容易，尽管它会给我警告，并不断显示剩余里程。而且它不知道充电站在哪里，所以我必须知道充电站在哪里（在我手机的应用程序中）。
Yeah - we’re entering the second (or possibly third) generation of the technology - and lessons learned on those earlier EV’s are being solved on the latest ones.
是的，我们正在进入第二代（或者可能是第三代）技术，早期电动车的经验教训正在最新的电动车上得到解决
The people who ask might not realize that an EV displays SOC on the dashboard, and the driver will check it before any trip just as they would look as a fuel gauge.
So perhaps they imagine that an EV is like a flashlight—it works for a while, and then the battery dies unexpectedly.
Even though our phones also show SOC in plain sight. As do laptop computers. And electric vehicles.
We’re not in the 1970’s any more, with crude or nonexistent gauges, and come to think of it I haven’t run a car out of gas since the 1980’s either.
问这个问题的人可能没有意识到，电动汽车的仪表盘上会显示SOC，司机在任何行程前都会检查它，它们看起来就像一个燃料表一样。
所以他们可能会把电动汽车想象成手电筒——它能工作一段时间，然后电池意外地耗尽。
尽管我们的手机也显示SOC。笔记本电脑也是如此。电动汽车也是一样。
现在已经不再是70年代了，那时候的测量方式是粗糙的或者根本就不存在，想想看，自20世纪80年代以来，我还没有把车的汽油用光过。
But it's easy to overlook the fuel gauge, and it happens all the time. So it's not surprising that some people assume that the same would happen in an EV. In reality, if you normally plug in when you get home each day, there's nothing to check each morning. It's possible to forget to plug in, just as it's possible to forget to close the garage door, but when people do something out of habit, they tend not to forget.
但人们很容易忽视燃油表，而且这种情况经常发生。所以有人假设电动车也会发生同样的情况也就不足为奇了。事实上，如果你每天回家时都正常插上电源，那么每天早上就没有什么要查看的了。可能会忘记插上电源，就像可能会忘记关车库门一样，但当人们出于习惯做某事时，他们往往不会忘记。
Yes - exactly. For daily driving, you just never worry about it. The battery is always full (or close to it) so you go to work and back, drop the kids off, do shopping…whatever - and you never have to think about charging - because you always plug the car in when you get home.
For road trips - you tell the car where you’re going - and it figures out how to get you there with enough charging stops to be guaranteed that you’ll have enough battery charge to do it.
It’s a total no-brainer.
I only look at the battery charge meter out of curiosity more than anything.
You could do the same thing with a gas car…stop at the gas station every morning and stick a half gallon in there when it needs it. But that’s such a monumental pain in the butt that (obviously) nobody does that.
So after days and days of NOT filling up the tank, there’s a definite risk that you might not notice that the gas tank is getting kinda low.
是的，没错。每天开车，你就不用担心了没电了。电池总是充满(或接近)，所以你每天去上班，回家，送孩子，购物……无论干什么——你永远不需要考虑充电——因为你总是在你回家的时候给汽车充电。
在公路旅行中，你告诉汽车你要去哪里，它会知道如何把你带到那里，并保证你有足够的电池充电。
这完全不需要你自己动脑筋。
我只是出于好奇才会看电池充电表。
你可以对汽油车做同样的事情，每天早上停在加油站，在需要的时候加半加仑油。但这实在是太痛苦了，（显然）没有人这样做。
所以在几天又几天不加油之后，你肯定会注意不到油箱里的油越来越少了。
I hope that EVs show a state of charge that is MUCH more accurate than what phones do, even when the batteries are starting to lose capacity.
我希望电动汽车能显示出比手机更准确的充电状态，即使电池开始失去容量。
Battery & Power management in Teslas is MUCH more sophisticated than phones.
特斯拉的电池和电源管理比手机复杂得多。
Yeah - in the range remaining mode - it seems to know whether you’re highway driving or not and (possibly) the ambient temperature, etc.
是的，在续航模式下，它似乎知道你是否在高速公路上行驶，以及周围的环境温度等等。
You make a great point. The Battery Management System in most electric vehicles is much more advanced than what we find in our phones or laptops, but it can get things wrong.
I have a Nissan LEAF. This morning it showed 75 miles of range while the battery was fully charged. I knew it won’t go that far—I get about 65 miles at best, unless I drive very easy. So if I was counting on that estimate to drive to a destination 70 miles away, I could have gotten stranded.
Luckily as it comes down from a full charge, the range estimate becomes much more realistic. By the time I get a “low battery charge” audible warning from the car, it usually shows about ten miles left, and in my experience I can drive that far. I’ve never driven it down to zero, but with ten miles remaining I’ve driven six, and the car still shows 4 remaining.
The other two cars we’ve driven are a Chevy Volt and a Bolt EV. Both show a relative indication of charge remaining, estimated miles left, and also show how many kWh have been used since a full charge. The Volt is unique because it has a gasoline engine so we can drive it until the charge is fully depleted. The estimate of kWh remaining can be easily calculated from usable capacity minus kWh used. I’ve considered it reliable, and other than the Volt which has a gasoline backup, I’ve never run the other cars out of charge.
Some people call the range estimate a “guess-o-meter” because it can be clearly wrong. It is based on how the car was driven prior, and driving conditions or weather can cause the estimate to be either higher or lower than actual. But I get used to reading it, and if driving a long distance I make sure I am never out of range to reach a charging station.
你说得很对。大多数电动汽车的电池管理系统比我们在手机或笔记本电脑上看到的要先进得多，但它也可能出错。
我有一辆尼桑聆风。今天早上它显示电池充满电的时候能跑75英里。我知道它开不了那么远——我最多开65英里，除非我开得很轻松。所以如果我指望这辆估计能够开到70英里外目的地的车，那我可能会陷入困境。
幸运的是，当它充满电后，距离估计变得更加真实。当我听到汽车发出“电池电量不足”的声音警告时，它通常显示还剩10英里，而根据我的经验，我可以开这么远。我从来没有把它开到电量还剩零，但在还剩10英里的时候我开了6英里，车显示还剩4英里。
我们驾驶的另外两辆车是一辆雪佛兰Volt和一辆Bolt EV。两辆车都显示了剩余电量的指示，估计的剩余里程，也显示了充满电后使用了多少千瓦时。沃蓝达的独特之处在于它装有汽油发动机，所以我们可以一直开到它的电量耗尽为止。剩余千瓦时的估计可以很容易地用可用容量减去已使用千瓦时来计算。我认为它是可靠的， 而且除了有汽油备用功能的Volt，我从来没有让其他汽车在没电的情况下运行过。
有些人把距离估计称为“猜测表”，因为它很可能是错误的。这是基于汽车之前的驾驶方式，驾驶条件或天气可能导致估计值高于或低于实际值。但我习惯了，如果我开车很长一段距离，我会确保我永远不会超出到充电站的范围。
The gasoline engine in the Chevy Volt does not charge the battery?
雪佛兰沃蓝达的汽油发动机不给电池充电？
It does, but it doesn’t run constantly. Whenever there is charge remaining the driver can choose whether to run on gasoline (saving battery charge) or run on electricity only (saving gasoline). In the default mode, the gas engine won’t start until the battery is fully depleted.
So it is possible to drive the Volt short distances as if it were a pure electric vehicle. I included it in the comparison above with the Bolt and LEAF simply to describe the Volt’s dashboard characteristics and how it displays charge used/remaining.
But unlike the others, the Volt I could drive until the battery was depleted (about 40–50 miles) and not be stranded.
它会给电池充电，但不会一直运行。当有剩余的电量时，司机可以选择是使用汽油（节省电）还是只用电（节省汽油）。在默认模式下，汽油发动机不会启动，直到电池耗尽。
因此，Volt可以像纯电动汽车一样短距离行驶。我将它与Bolt和LEAF进行了比较，只是为了描述Volt的仪表盘特征以及它如何显示使用/剩余电量。
但与其他车型不同的是，我可以一直开到电池耗尽（大约40-50英里），而且不会抛锚。
I won’t apologize for being an “EV hater”. Yes, technology is getting better day by day! Right now, the tech is too much in its infancy. I’m convinced it will get better! But no one is talking enough about the negatives and there are PLENTY!
How many people have run out of gas simply because they ignore the gauge, or worse yet the “low fuel” warning light, figuring they can stretch it out to the next station? Sure, more and more recharging stations are being built every day, but the charge doesn’t happen quickly enough to continue a long trip. The nation’s current (pun intended) power grid is severely outdated and overburdened now! The transmission power lines haven’t been replaced in decades, if ever! The exorbitant costs of ownership haven’t been mentioned very often, either! Recharging at home IS possible but some significant (and somewhat expensive) upgrades to your home’s electrical wiring will be required to handle the extra demand. And, not many people have considered what might possibly happen around their own neighborhoods. Again, as more and more EV’s are purchased and plugged in within those areas, “brownouts” or even complete blackouts could become more commonplace.
Today’s society is too heavily dependent on fossil-fuel-produced electrical energy! Right now, the disadvantages outweigh any useful benefits!
我不会为自己是“电动车仇恨者”而道歉。是的，现在的技术一天比一天好！目前，这项技术还处于起步阶段。但是没有人谈论足够多的负面因素，而且负面因素也很多！
有多少人只是因为忽略了里程表，或者更糟糕的是忽略了“低油”警示灯，以为可以延长到下一站，就把汽油用完了？当然，每天都有越来越多的充电站在建设，但充电的速度还不够快，无法持续长途旅行。这个国家目前的电网已经严重过时，负担过重了！输电线路几十年来都没有更换过，前提是如果有的话！高昂的成本也不常被提及！在家充电是可能的，但需要对家里的电线进行一些重大的(有点昂贵的)升级，以应对额外的需求。而且，没有多少人考虑过他们自己的社区可能会发生什么。同样，随着越来越多的电动汽车被购买并在这些地区充电，“限电”甚至完全停电将变得更加普遍。
今天的社会过于依赖化石燃料生产的电能！现在，弊大于利！
It’s not like petrol cars are any different. You’ll still be on the tow truck if you run out of fuel.
这和汽油车没什么不同。如果你没油了，你还会在拖车上。
原创翻译：龙腾网 http://www.ltaaa.cn 转载请注明出处
Well, you can’t take a jerrycan and walk to the nearest charging station. But in either case, it’s a result of very poor planning and total inattention, neither of which are good qualities when driving a car.
是的，你不能拿着油罐走到最近的充电站。但无论哪种情况，这都是由于非常糟糕的计划和完全的疏忽造成的，这两种情况都不是驾驶汽车的好品质。
Or like the last time I ran out of gas, a faulty fuel gauge.
或者就像上次我没油了一样，因为油表有问题。
Portable battery packs are a little pricey, but it takes about 360 Wh/mile for a Tesla 3 and you can get 1000 Wh battery packs easily. More likely you call for a tow and the electric tow truck gives you enough juice to get to the next charging station.
便携式电池组有点贵，但特斯拉3大约需要360 Wh/英里，你可以轻松获得1000 Wh电池组。
更有可能的情况是，你叫了辆拖车，电动拖车给你足够的电量去下一个充电站。
The same exact situation applies to a petrol motor car if a driver does not bother to monitor the fuel gauge and runs out of fuel they’ve got two choices hire a tow truck or pay for a taxi to take them to the nearest petrol station to get some more gas and then run back and refill the tank and try and get back to the Petrol station to fill the rest up. The big difference though is its much easier to get a petrol car going again without a tow where as unless there is some kind of portable charger you won’t get an electric car running again, however yeah electric is the way to go in the future or perhaps hydrogen power I’m sure all the oil companies have bought these idea’s up for the future when oil does eventually run out then they’ll make another fortune on alternative fuels. Just like driving a Taxi that runs on LP gas the driver knows he can only go so many Km on a tank so he monitors the amount of km he’s done then when its getting close he’ll start looking somewhere for an LP gas outlet.
同样的情况也适用于汽油发动机汽车，如果司机不费心去监控燃油量表和燃料耗尽情况，他们有两个选择，雇佣一个拖车或支付一辆出租车带他们到最近的加油站拿回更多的燃料，然后跑回去把油箱加满，然后再去加油站把剩下的油加满。不过最大的区别是，汽油车在没有拖车的情况下更容易发动起来，而除非有某种便携式充电器，否则你就无法让电动车再次发动起来，但是，是的，电力是未来的发展方向，或者可能是氢能源，我相信所有的石油公司都相信这些想法，未来当石油最终耗尽时，他们会在替代燃料上赚一笔。就像驾驶一辆使用液化石油气的出租车，司机知道他的油箱只能开这么多公里，所以当里程接近时，他会监控自己的里程数
原创翻译：龙腾网 http://www.ltaaa.cn 转载请注明出处
For those without Teslas that have to rely on public J1772 charging stations it isn’t stupidity that gives us a case of range anxiety it’s the lack of upkeep, maintenance, and lower numbers of chargers that simply aren’t there or aren’t working or aren’t available.
I have multiple apps to find chargers but they can be hard to find even with navigation. I remember once early on trying to find the only charging potential in a journey just north of San Francisco and it turned out to be a 110 plug in a shopping mall on a light post. Not only that but the slots were painted over so we had to scrape the paint off before plugging in. The plug worked though so there’s that:)
This illustrates a problem with the J1772 charging infrastructure that is at times very spotty, broken or in use when you get there. I make a point of going into anchor businesses wherever I shop and asking the business if it plans to install a charger or 2 in their parking lot. I’ve gotten a few businesses to do so which has been gratifying.
对于那些没有特斯拉、不得不依赖公共充电站的人来说，让我们焦虑的并不是愚蠢，而是缺乏维护，以及根本就没有、不能工作或无法使用的较少的充电站数量。
我有很多找充电器的应用程序，但即使有导航，也很难找到。我记得有一次在旧金山北部的旅途中，我试图找到唯一的充电站，结果是在一个购物中心的灯柱上安装了插头。不仅如此，插槽还被粉刷过，所以我们不得不在插入之前刮掉油漆。但是插头工作正常，这说明了充电基础设施的一个问题，当你到达那里时，它有时非常不稳定、被损坏了或者能够正在使用。
无论我在哪里购物，我都会去找一些固定的公司，问他们是否打算在停车场安装一个或两个充电器。我已经让一些企业这样做了，这让我很满意。
原创翻译：龙腾网 http://www.ltaaa.cn 转载请注明出处
First road trip in my Tesla and I couldn’t be more pleased. It told me where to stop, how long to charge.
我第一次开着特斯拉开车旅行，我非常高兴。它会告诉我在哪里停车，充电多长时间。
Nowadays they show up with batterypacks to charge your traction battery so you can go to the nearest charger. Quite a bit simpler than fixing an ICE car that ran out of fuel.
No air that needs to be purged from the fuel system.
No pump that might be dead from lack of lubrication.
现在他们带着电池包给你的牵引电池充电，所以你可以去最近的充电站。比修理一辆没油的汽车简单多了。
不需要从燃料系统中清除空气。
没有可能因缺乏润滑而损坏泵。
How about if there is a queue at the charging station and you will have to wait an hour just to get connected? Might you try to make it to the next charging station knowing you should just make it, but the battery in the car is old and doesn't go quite as far as calculated?
These are the sort of issues that, being an Australian with the long travel distances in Australia, keep me from getting an EV.
I will wait for decent EVs with range extender petrol engines. The small petrol engine is super efficient as it only runs at a set speed and throttle, and it only charges the battery. It may only kick in when the battery is three quarters flat or you stop for a while for lunch to boost the charge enough to get to the next charging station. Then there need be no fear of a big tow truck bill.
如果充电站前排了队，你要等一个小时才能充电呢？你会不会试着到达下一个充电站，汽车显示你应该能到达充电站，但汽车的电池是旧的，不能走得像计算的那么远？
作为一个在澳大利亚长途旅行的澳大利亚人，这些问题让我不想也无法买电动汽车。
我会等待带有增程汽油发动机的电动汽车。这台小型汽油发动机非常高效，因为它只在设定的速度和油门下运行，而且只给电池充电。它可能只在电池电量不足四分之三或你停下来吃一段时间的午餐的时候，充足够的电量以便能够到达下一个充电站，那就不用担心高额的拖车账单了。
What you have failed to note is that the batteries require 2 hours to charge, compared to about 5 minutes to fill up a tank of gas. With about a 200 mile range for a fully charged battery, electric cars are fine for local commuting, but useless for long road trips, unless you plan on stopping for two hours every 200 miles to recharge, assuming you can find a charging station.
你没有注意到的是，电池充电需要2小时，而加满一箱油需要5分钟。电池充满电可以行驶200英里左右，电动汽车适合当地通勤，但对长途公路旅行毫无用处，除非你打算每行驶200英里就停车两小时充电，前提是你能找到充电站。
Its the same what would happen to a petrol car if despite showing E on fuel needle you don't get it filled up and drive it.It is a stupid question in the first place, No. It is just a matter of time when it will be difficult to find Fuel stations. Instead there will be only charging stations mainly.
这和汽油车的情况是一样的，即使在油针上显示了E，你也不加满油而继续开它。首先这是个愚蠢的问题。加油站很难找到，只是时间问题。取而代之的将主要是充电站。
I would argue it’s easier to run out of petrol than to run out of charge in an EV.
My Tesla really goes out of it’s way to make sure I know. Multiple warnings, directions to chargers etc.
我认为，用光汽油比电动汽车没电要容易得多。
我的特斯拉真的竭尽全力让我知道还有多少电量。多重警告，充电器指示等。
In addition, electric vehicles are far more accurate with their estimate of remaining travel distance. The guage on E might mean you can drive another 10 miles, or another 50. Electric vehicles will tell you exactly how far you can go based on past driving habits.
此外，电动汽车对剩余行驶距离的估计要准确得多。里程表的显示可能意味着你可以再开10英里，或50英里。电动汽车会根据你过去的驾驶习惯精确地告诉你可以行驶多远。
Well, my 2013 Audi also popped up a message on the big screen when fuel got low asking if I wanted directions to the nearest fuel station, so I imagine these types of helps are getting more common on ICE cars too, but yes, it’s hard to accidentally run a Tesla’s charge down to zero.
我2013年的奥迪也在大银幕上出现一个消息，当燃料低时问我是否想要到最近的地方加油，所以我想这些类型的帮助在燃油汽车上也越来越常见，但是，是的，很难不小心让特斯拉的电量降到零。
Maybe this is more valid for non telsa evs were you have less range and public chargers could be broken.
也许这对非telsa电动汽车更有效，因为你的里程更短，公共充电器可能会坏掉。
The public chargers being broken thing has got massively better in recent years.
And I also think non-Tesla owners (the Leaf, for example) are more likely to be using them for just a predictable drive like a commute, where they’ll charge at home every night and hence the battery going flat is just never a consideration.
最近几年，公共充电器被损坏的情况已经有了很大改善。
我还认为，非特斯拉车主(比如Leaf)更有可能将其用于可预测的驾驶，比如通勤，他们每天晚上在家充电，因此电池没电根本就不是一个考虑因素。
The EV will give you plenty of warning that your charge is getting low. It will inform you where the nearest charge point is and direct you to it. If you are unwilling or unable to act on the warnings it will slow down and attempt to conserve power as much as possible. Eventually it will stop. At that point you will have to seek assistance.
in the case of an ICEV you will get a warning light. If you do not act on that warning your ICEV will eventually stop. At that point you will have to seek assistance. You may also damage the catalytic converter.
In both cases you will be inconvenienced. The main difference is that your EV will give you more warnings and will usually have been fully charged before you set out on your journey making it less likely that you will run out of fuel.
电动汽车会给你足够的警告，你的电量正在变低。它会告诉你最近的充电站在哪里，并指引你去那里。如果你不愿意或不能对警告采取行动，它就会放慢速度，并试图尽可能地保存能量。最终它会停止。在这一点上，你将不得不寻求帮助。
在ICEV的情况下，你会得到一个警告灯。如果你不采取行动，警告你的ICEV最终会停止。在这一点上，你将不得不寻求帮助。你也可能损坏催化转换器。
这两种情况都会给你带来不便。主要的区别是，你的电动汽车会给你更多的警告，通常会在你开始你的旅程之前充满电， 这样你就不太可能耗尽燃料。
Let me preface my answer with stating that I am NOT a fan of EVs - because they use resource limited elements for their batteries and recycling of those batteries is going to become a huge problem but…
You will get lots of warnings that you are running low on juice.
在回答这个问题之前，我想说我不是电动汽车的粉丝，因为电动汽车的电池使用的是资源有限的元素，回收这些电池将成为一个巨大的问题，但是……
你会收到很多警告，显示你的电量快用完了。
What happens if an electric car runs out of charge while driving?
So you have been driving a conventionally fuelled vehicle for years, perhaps run out of fuel once or twice, then discovered this incredibly useful thing called a ‘fuel guage’ .
Amazingly, this thing tells you roughly how much fuel you have left.
Some vehicles tell you how much range you have left before you need to refuel.
如果电动汽车在行驶时没电了怎么办？
你开了几年的传统燃料车，可能会有一两次燃料耗尽，然后发现了这个非常有用的东西，叫做“燃料表”
令人惊讶的是，这东西能告诉你大概还剩多少燃料。
有些车会在你需要加油前告诉你还剩多少里程。
Same thing that happens if you run out of gas. You have to get more. That requires towing it to the gas or charging station.
Gas stations are more common and frequent than chargers, currently, so there’s a better chance you could walk to a gas station and get a can of gas to take back to your car, avoiding a tow. But eventually that won’t be the case. I suspect when EVs become common, “emergency chargers” might be placed strategically along highway shoulders to alleviate this problem. But it’s going to be a very small problem, for reasons explained in other answers.
I only ever ran out of gas in my car one time in my life. It was when I was a teenager, still driving cheap, old junkers, and the fuel gauge didn’t work. I used to fill up, and use the trip odometer as an ad-hoc fuel gauge (I knew I could go 400 miles on a tank), but one time I didn’t have enough money to fill up entirely, and I miscalculated my range.
Nowadays cars tell you exactly how many miles you can go before you’ll run out, and there’s no reason but negligence for running out of gas in a car with a working fuel gauge. The same is true of electric cars and battery gauges.
就像你没油了一样，你必须加油或者充电，这就需要把车拖到加油站或充电站。
目前，加油站比充电站更常见，使用也更频繁，所以你有更好的机会走到加油站，拿一罐汽油带回到你的车，避免你的车被拖走。但最终情况并非如此。我怀疑，电动汽车普及后，“紧急充电器”可能会战略性地放在公路边上，以缓解这个问题。但这将是一个非常小的问题，原因在其他回答中有所解释。
我这辈子只有一次车没油了。那是我十几岁的时候，还开着便宜的旧破车，油表坏了。我过去常常把车加满油，并把里程表当作临时的燃油表（我知道我一个油箱可以跑400英里），但有一次我没有足够的钱把油完全加满，所以我计算错了里程。
如今，汽车会准确地告诉你在你用完油之前你还能跑多少英里，而且在一辆有油表的汽车里，没有理由只因为疏忽而把汽油用完，电动汽车和电池表也是如此。