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Transportation Hardware Hacking Power Build

Hacking the Nissan Leaf EV 199

An anonymous reader writes "The New York Times is running a story on people hacking the Nissan Leaf electric vehicle. 'Using Mr. Giddings’s home-brewed E.V. fuel-level display, Leaf drivers get the confidence to extend their driving range by 10 percent or more. His gauge, which displays the actual state of charge, reveals that the Leaf dashboard’s "zero bars" display comes on when the battery pack has several miles remaining.' Here's an interesting quote from one of the hackers, Phil Sadow, who was interviewed for the story: 'I don't like the term hacking because it's been portrayed by the media as something evil. To me, hacking is actually very American. Go out to the garage. Take it apart. Make it better.'"
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Hacking the Nissan Leaf EV

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  • Better you say? (Score:5, Insightful)

    by BiggerIsBetter ( 682164 ) on Sunday October 16, 2011 @04:17AM (#37729140)

    Perhaps Nissan knows something about their batteries and BMS that he doesn't, and the false zero reading is there to ensure the batteries last as long as they're intended to? Last I heard, you weren't supposed to completely discharge lithium batteries if you wanted to ensure a usefully long service life.

    • Re:Better you say? (Score:4, Insightful)

      by queazocotal ( 915608 ) on Sunday October 16, 2011 @04:21AM (#37729148)

      Taking cells all the way to 'zero' in a battery is generally a bad plan, it both stresses the cells more - discharging them at high currents at the very end of the discharge is harsh on them, causes extra wear due to deeper cycle life, and risks overdischarging weaker cells in the battery.

    • Re:Better you say? (Score:5, Insightful)

      by jtownatpunk.net ( 245670 ) on Sunday October 16, 2011 @04:26AM (#37729164)

      It's also probably intended to keep people from running out of juice on the freeway or some other place where it would be dangerous to be unable to move the vehicle. Honestly, if you're down to the last few miles, it's time to recharge.

      • by mirix ( 1649853 )

        Bingo, it's not like the idiot light on a normal car fires *after* it's empty. That sort of defeats the purpose...

      • It's kinda like starving yourself until your doctor is ready to pull the plug to save on groceries.
    • by dutchwhizzman ( 817898 ) on Sunday October 16, 2011 @04:57AM (#37729270)
      It just shows how much of the last bar you still have. Once you go from one bar to zero, you essentially only know you have "less than one bar" left, but not how much. There is no change to how deep the batteries get discharged, you just know better what risk you are taking if you decide to drive on. The TFA also tells about the software "hack" to the 120V charge cable to make it work with 240V as well. That's not so special, considering the same cable is used with different software in Europe, where 240V is the standard. Also improving it to be better, but not different.
    • Perhaps Nissan knows something about their batteries and BMS that he doesn't, and the false zero reading is there to ensure the batteries last as long as they're intended to?

      There's other possibilities too... Maybe there's an oddity in the discharge curve right near the bottom, or in the capacity reading right near the bottom, or the metering system isn't quite 100% reliable near the bottom...

      I don't care what kind of engineer you are, if you don't have the fulls specs and know all of the considera

    • Perhaps Nissan knows something about their batteries and BMS that he doesn't, and the false zero reading is there to ensure the batteries last as long as they're intended to? Last I heard, you weren't supposed to completely discharge lithium batteries if you wanted to ensure a usefully long service life.

      Yes, it's called "deep cycling" and it's something that you don't want to do to pretty much any type of secondary cell.

    • Most likely, it's either a liability thing, or a "don't piss off the customer" thing.

      For instance, I read a story once that many years ago, Cadillac tried to fix its fuel gauges. They did; they made the fuel gauge linear, so the gauge correctly showed the amount of fuel that was left: the 3/4 mark meant 3/4 full, the 1/2 mark meant 1/2 full, and the empty mark really did mean empty. But then customers got really angry: they complained their cars were guzzling gas (!), and that they were running out of gas

      • Otherwise, people will run out of battery power because they think they only have 10 miles left to go, when in reality they have another 15.

        It would be interesting to link the battery management firmware with the car's GPS. If it knows where you're going, it could tell you that you can't make it, or give you the option of risking your battery pack to get there.

  • To me, hacking is actually very American. Go out to the garage. Take it apart. Make it better.

    Sad then that so many american companies are actively trying to restrict or remove people's abilities to do just that, especially on computers where unlike a car anyone can get into it without the need for specialist tools and there is no potential safety risk etc.

  • Gas powered cars still go many miles after the gas gauge hits empty. A fuel gauge reading empty is suppose to tell you "Fill up as soon as possible" not tell you need to get out and push.

    • by vlm ( 69642 ) on Sunday October 16, 2011 @06:47AM (#37729554)

      Gas powered cars still go many miles after the gas gauge hits empty. A fuel gauge reading empty is suppose to tell you "Fill up as soon as possible" not tell you need to get out and push.

      Empty means buy a new fuel pump because the old one just sucked up all the water, rust, sand, whatever from the bottom of the tank. Also the in-tank pumps are notorious for overheating and burning out in air/vapor and only running cool when immersed in fuel, so even a perfectly clean tank can burn out the pump if the pump is in an empty tank. Maybe more so in summer than winter... Also if the pump fails after pumping rusty water for awhile rather than instantly, you'll probably end up replacing the fuel filter, maybe the injectors, who knows.

      • by swalve ( 1980968 )
        Fuel pumps don't move. They always suck from the bottom of the tank. Overheating is a possibility, but even that is doubtful for a pump that is not already on its way out. I mean, if the motor can get hot enough to overheat, that would mean it is getting hot enough to vaporize the fuel in the tank, and that's not a good thing. Most pump designs I've seen have a small reservoir that the pump is submersed in at all times, and if the fuel level is low enough to empty that reservoir, the car quits running i
        • by Richy_T ( 111409 )

          I have heard of the overheating issue and have seen places where it could theoretically physically be an issue. The sucking up water & rust I'm in complete agreement with you. The only possible issue there would be from crap floating on top of the gas.

      • by BillX ( 307153 )

        Can you explain this bit about pumping water when the tank is empty? I understand condensation can cause there to be a small amount of water in the gas tank, but last I checked water is heavier than gasoline (it should generally be the first thing pumped). In fact, pilots of some small aircraft - I have seen this done - draw a small amount of fuel from the bottom of the tank into a syringe to check for water bubbles before takeoff.

        Also, "sludge" (rust, other particulates) can be a specific problem of empty

  • by jamesh ( 87723 ) on Sunday October 16, 2011 @05:57AM (#37729428)

    If he wants to extend the range, he could try installing one of these [wikipedia.org]...

    • Or figure out a way to stuff one of these in the car....
        http://gigaom.com/cleantech/hyperions-nuclear-in-a-box-ready-by-2013/ [gigaom.com]

    • Comment removed based on user account deletion
      • In researching/discussing the different Hybrids, we've determined that both the Prius and Volt are Parallel hybrids; meaning they can run on battery or ICE. The Honda hybrid though is a Series design; meaning that the ICE must run to get anywheres. If you're looking for mileage, buy the normal Civic and get the same mileage with lower emmisions instead of the added complexity.

        If I were in the market I'd stick with the Volt model for now. It just makes more sense to have that ICE tether

        This is the direction we're figuring on going depending on whether we can get the Volt. I like the styling a bit better then the Pri

      • by spage ( 73271 )

        How is it a "leap of faith" to drive within the range of the vehicle? Range anxiety seems to plague people who don't own an electric car... actual owners not so much. Every morning they get in a car they've cheaply "refueled" overnight, do their usual boring commute and shopping run, and return home. If you sometimes find yourself in the middle of nowhere on an unplanned road trip to Vegas, use a different vehicle. There's probably one nearby, since most households in the USA have multiple cars.

      • by Richy_T ( 111409 )

        Maybe the AAA could furnish people with towable generators?

  • by crow_t_robot ( 528562 ) on Sunday October 16, 2011 @06:33AM (#37729536)
    Bottoming out batteries is absolutely retarded. Even "deep cycle" batteries are only supposed to be discharged to 20% AT THE VERY LOWEST. And doing so reduces the number of cycles by orders of magnitude. Another thing to point out is that batteries become EXTREMELY non-linear in discharge rate at the bottom of their SoC. I like his comment about hacking but everything else is retarded.
    • Deep cycle batteries are a type of lead-acid battery. The Leaf uses lithium-ion batteries, which behave very differently. Still, lithium-ion batteries should never be fully discharged, which may be a risk with his modifications.

      Any program that measures charge is making a educated guess based on the past behavior of the battery. One of the people interviewed for the article states: “Until you can find out how much is really left in the batteries toward the end of its range, it’s just a guess-o-m

    • Bottoming out batteries is absolutely retarded. Even "deep cycle" batteries are only supposed to be discharged to 20% AT THE VERY LOWEST. And doing so reduces the number of cycles by orders of magnitude. Another thing to point out is that batteries become EXTREMELY non-linear in discharge rate at the bottom of their SoC. I like his comment about hacking but everything else is retarded.

      If 20% is the "very lowest", then the scale should be recalibrated so that 20% is the new 0%.... :)

  • There were articles earlier in the year saying that the Leaf could be used to power the home in case of emergency, or to give back to the home that is powered by the sun by day and Leaf at night. I asked a guy at the local Nissan dealer when I took my La Festa in for a checkup if I could just have the battery system without the car. He looked at me strange and asked why? I told him that I was looking into alternate energy systems (wind and solar), but none of the solar packages being sold store the power
    • "If the Leaf has a single package that can easily connect to the home to charge and discharge, it would be a great help"

      It's a good notion, but you would be paying a premium for a highly compact and portable power supply that you don't actually need to be highly compact or portable.

      And don't use car batteries either, they don't like deep discharge. Use deep cycle batteries like from electric forklifts or golf carts. At the moment, lead-acid batteries are still the cheapest option.

    • I actually have such a system installed in my home, it's basically just a 3600w charger/inverter hooked up to a bank of 12 12v 110Ah lead gel cell batteries in a series/parallel configuration (The inverter is more efficient working with 24v on the battery side). These aren't old car batteries, as you say, but rather purpose built for this kind of work. The whole thing installs just fine into a closet (Which happens to be the closet where my breaker panel is located.)

      Now, I don't do solar or anything like
  • by dr2chase ( 653338 ) on Sunday October 16, 2011 @08:01AM (#37729836) Homepage

    This suggests that there's a lot to be said for not driving your battery charge down to "zero" (as defined by the battery controllers and the 3V limit). You'll get many more cycles if you avoid the extremes (full charge, full discharge).

    http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries [batteryuniversity.com]

  • Originally, the Leaf's battery meter was more accurate. Zero really meant zero.
    One of the first problems reported by new Leaf owners was that they would run out of power while on the road, because they were expecting the meter to work like a typical gas meter, where zero means "fumes", with a few miles to spare.
    There was a firmware upgrade, I believe in May 2011, that changed the meter so that zero means about 10 miles. Also Nissan recommends that you only charge to 80% capacity, for increased battery life.

    • by Animats ( 122034 )

      Right. Auto fuel gauges have had some margin in them for decades.

      Aviation fuel gauges, incidentally, do not. Zero is zero.

    • by Richy_T ( 111409 )

      Do you also set your clock five minutes ahead to get to appointments on time?

      I really don't understand why some people need to be lied to to operate properly. And it's absolutely infuriating when I stumble over the results of it too.

  • Hacking is only portrayed as evil because a lot of reporters don't know what it means, they just base their ideas on crackers, phreakers, and black hats. This is truly a hack in every sense. Own it and give the word back its original meaning. Hacking is not a negative or positive thing, it's a term for an act that may lead to negative, positive, or neutral results.
  • Phil Sadow, who was interviewed for the story: 'I don't like the term hacking because it's been portrayed by the media as something evil. To me, hacking is actually very American. Go out to the garage. Take it apart. Make it better.'"

    I, on the other hand, love the term "hacking". News media have put a negative spin on the word, but I think we should take it back rather than let them have it. A hacker is nothing more than someone who gets into the guts of things to see how they work and to do cool things w

  • I have hacked my car so that it no longer tells me I'm out of gas until it actually is.

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