The state of California is expected to be hit by a large storm in the coming days and there are frequently clogged drains in my town. I have an electric vehicle that seemed to handle driving through large puddles during the last storm but I was curious if anyone could tell me what the potential hazards are of driving an EV through a large standing pool of water.

I don't need to worry about getting water in the engine (I think) since there is no air intake. There are fans that cool the battery if it gets too hot but I don't think that will be a problem during this storm.

EDIT: I have a Ford Focus

  • 1
    Well, do you have a Fisker Karma? sayanythingblog.com/entry/…
    – Nick
    Dec 10, 2014 at 1:48
  • You say you have an EV, but not what kind. They are not all alike and won't exhibit the same tendencies. Pleas etell us what you have for a much enhanced answer. Dec 10, 2014 at 1:54
  • @Nick ... I've often wondered if any EV (or hybrid) would behave much the same if flooded. Your link was showing several Fisker Karmas together which all went up in smoke. I don't like Fiskers at all, so that doesn't bother me. I'm just wondering if this is a systemic problem with EVs is all. All it would take is contaminated water as an electrolyte, shorting a battery, which has a high discharge rate, and you'd have lots of heat from it. I'd hate to be standing in water near such a vehicle, that's for sure. Dec 10, 2014 at 11:58

3 Answers 3


Electric cars use high tech lithium batteries. These batteries are dangerous in a variety of situations but they're also full of electronics to compensate. If anything at all bad happens (for example, a short circuit due to water) the battery itself will shut down, and you'll have to get the car towed.

Cars are expected to handle all kinds of weather and Ford is a reputable company. I would expect all high voltage power sources to be perfectly protected from water splashing up from the wheels which would mean shallow water is fine. If the water gets up into the doors though, then you might be in trouble.

Doing some research, I found someone who's nissan leaf that was submerged for an extended period it of time (the water was half way up the door, wheels totally under water) and the car computers had detected various faults and shut everything down. A mechanic cleaned things up as best they could and the car was able to start, but more errors were detected so they declared the car a write off.

My guess is that car could have been repaired if it was taken to a more competent mechanic, but most mechanics don't know anything about electric vehicles and they're not going to risk telling you everything is fixed when they honestly don't know.

Tesla says that there is no safety risk at all if the car is fully submerged in water, but obviously it would destroy the car just like happened with the Leaf. If the battery catches fire they recommend using "large amounts" of water to cool the batteries down. You're likely to need to keep the battery cool for up to 24 hours, so make sure you have a lot of water available to keep the batteries cool.

My understanding is water won't put out a lithium battery fire, but it should prevent the fire from spreading into neighbouring battery cells, and eventually the ones already burning will run out of fuel.


I know this is an old thread, but Elon Musk tweeted a video of some people in Kazakhstan driving their Tesla through deep water. He then told that the Tesla can indeed operate as a boat, as the drive units and battery are sealed.

But of course, you could still get water in the AC and into the cabin. Then you would probably have to change all air filters, fans, etc. The AC intake is, as far as I know, located right below the windshield. The internal, low voltage, electronics are probably not sealed up, so there's lots of stuff that could take damage from standing water.

So if you plan turning your electric car into a boat, just remember to turn it back into a land vehicle as quickly as possible

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    Welcome to the site, great answer, and that last sentence is great advice pertaining to all vehicles, electric or otherwise! Thanks for contributing! Jun 21, 2016 at 16:15

The answer to this question is what was put into its design at the drawing board stage. Encapsulation and water proofing of components susceptable to being submerged in water being the main consideration. As an electric vehicle construction is usually decided by its weight, less weight means less drain on the battery means greater distance between charges, encapsulation would not be a consideration. So I would be reluctant to drive through puddles higher then the hubs of the wheel at any sort of speed.

  • Even with encapsulation, there is still going to be +/- terminals in there some where. I don't think I'd be driving a high voltage battery into somewhere it could be flooded and short out. I think it would get real ugly, real quick. Dec 10, 2014 at 12:00
  • @Paulster2 the +/- terminals on a good quality lithium battery are protected by electronics inside the battery - the terminals will be disconnected internally if the battery gets hot (which it will, if water short circuits them). Even small laptop batteries are supposed to have this feature, huge EV batteries would surely also have it. Feb 7, 2015 at 10:44
  • @AbhiBeckert ... not that I'm doubting you on this, but if you had a links to something describing what you are talking about, it would be a great addition to this answer. Feb 7, 2015 at 14:31
  • @Paulster2 I don't have a link sorry, it's just something I've learned over the years with regard to battery technology. Large lithium batteries are made up of thousands of cells and often the electronics to handle charging and discharging are more expensive than the battery itself. Improper charging or discharging of any lithium battery will either damage the battery or cause an extremely dangerous fire. Electronics inside the battery pack are monitoring and controlling everything that goes on. Feb 8, 2015 at 1:53
  • Wikipedia says this: "For notebooks or laptops, lithium-ion cells are supplied as part of a battery pack with temperature sensors, voltage converter/regulator circuit, voltage tap, battery charge state monitor and the main connector. These components monitor the state of charge and current in and out of each cell, capacities of each individual cell (drastic change can lead to reverse polarities which is dangerous),[40] temperature of each cell and minimize the risk of short circuits.[41]" Feb 8, 2015 at 1:56

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