Hacking the Nissan Leaf EV

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.'"

Comments

Better you say?

[BiggerIsBetter]

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?

[jtownatpunk.net]

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.

Re:Better you say?

[vadim_t]

No, you shouldn't with any kind of modern battery.

Li-Ion doesn't like full discharges, and in fact the internal circuitry should make it impossible. Lead-acid will very quickly become unusable if left fully discharged. And for battery packs, full discharge risks cell reversal, which causes damage.

The only case where you should still do that is when there is some sort of internal statistics being kept of how long the battery is estimated to last, which is out of sync with the actual battery.

That's not for any sort of cleaning though. It's just for fixing incorrect estimations of remaining battery time, which causes devices to turn off too soon, or have them fail to shut down nicely before the battery runs out.

Re:Better you say?

[Aqualung812]

It's simple economics;

No, it isn't so simple. There are many examples of expensive devices requiring many more manual steps because it gives the perception of value. "Mine requires more work because it is such a precision device" seems to be a very common thing.
Sometimes, this is a good thing, because it allows for better control by the end user *IF* they know what they're doing. SLR vs point & shoot, for example.
Other times, it is simply a status thing. For example, I have a solar powered watch that is synced to the atomic clock in Colorado every morning. My watch will always be within 0.5 seconds of actual time. However, a Rolex that costs thousands more doesn't include the solar charging or atomic clock sync will never be as accurate as my watch, and requires more effort. Still, a Rolex has the perception of higher value.