Very Low Battery Warning research

[UPDATE: This article was written in October, 2012 and applies to 2011 and 2012 model LEAFs. Nissan made some changes to the drivetrain for the 2013 model year. We wrote another article on the 2013 LEAF Low Battery Warning, which is slightly different than these earlier results (found here).]

If you just want to know how much farther you can go after the warnings, scroll down to the bolded text in the article.

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How much is really left when the warnings start?

We had some errands to run today, and as we did, we gradually realized that we were running low on juice. Having not run the battery this low in quite some time, we thought that this presented an excellent opportunity to do some research.

On May 12, 2011 Edmunds.com published an article on a range test that they performed on the LEAF. On a closed course oval driven at 35 miles per hour the LEAF achieved 132 miles exactly. Not really indicative of real world driving behavior. But we did learn useful bottom of range information. The Low Battery Warning (LBW) came on with 20 miles left (112.4). The Very Low Battery Warning (VLBW) came on with eight miles left (122). The Power limitation indicator light (otherwise known as Turtle Mode) came on with 2 miles left (130). Keep in mind, these remaining mile numbers were generated with a consistent slow speed with no terrain variation. Their LEAF had about 1,800 miles on it at the time.

Our experiment today was decidedly more real-world, if skewed in the other direction. With some errands already run, we don’t really know how many miles were already on the clock this morning. We charged to our usual 80 percent last night, and charging was completed at 4:26 AM this morning using only an end timer set to end at 5:00 AM. The LEAF reported being charged to 10 of 12 bars. This is not a total range test, but a remaining range test to find out how much range is left at the bottom after the warnings start to display. This is what we found.

Using the trip meter that had been set earlier in the afternoon (after our morning errands were already run) we noted that the Low Battery Warning came on with 37.0 miles displayed on the trip meter. The Distance Til Empty (DTE) meter read 9 miles. We didn’t note the bars remaining, but to the best of our recollection, there was one bar left. Driving immediately after this point consisted of freeway driving at 60 miles per hour and some city driving at speeds up to 45 miles per hour. We stopped at Costco for our next errand before heading home.

Upon arriving at home, driving again at speeds up to 45 miles per hour, the trip meter read 44.0 miles. Still no VLBW. We unloaded and headed out to continue our test. When we started the LEAF the DTE read – – – and there were zero bars. Pulling onto the parkway near our home we accelerated up to the 55 mile per hour speed limit and got the VLBW and flashing – – – DTE indicator at the 46.5 mile mark. This was new territory for us, as we had not before explored the range under the VLBW. Not wanting to venture too far from home we headed back in the other direction. As luck would have it, the next light turned red before we arrived. A lifted Toyota Tundra roared up next to us. We really had no thought of racing him (well… maybe a little…). When the light turned green we accelerated briskly, but not full throttle. The Tundra didn’t like that, and tried to catch up, which prompted us to “put the hammer down”. We were only going about 30 miles per hour or so, but the LEAF handily pulled away up to the speed limit of 55. The Tundra recognized that he was bested and backed off. We offer this only to point out the driving style that achieved these results.

Continuing our test driving ever more conservatively, we finally remembered to click it into ECO mode. Keeping our speed below 40 miles per hour from this point, we reached Turtle Mode with 53.7 miles indicated with a noticeable reduction in power. Heading home we were approaching the house when we felt a little hiccup in the drivetrain. As we turned into the driveway the LEAF’s motor stopped with 54.3 miles indicated. Our LEAF is sitting ten miles shy of 10,000 miles and is 19 months old.

So there you have it. Edmunds found that driving conservatively and on flat terrain, one might expect to go 20 miles from LBW, eight miles from VLBW, and two miles from Turtle. Driving quite a bit more aggressively on hilly terrain, we went 17.3 miles from LBW, 7.8 from VLBW, and .6 miles from Turtle.

We don’t hold this out as any scientifically determined approach to estimating what you might expect. With careful driving one should expect to see better numbers than ours. We seriously doubt that anyone would be more aggressive than we were during this test. Our hope is that the information will prove useful to you should you find yourself in a real-world LBW situation.