Nissan LEAF

How to avoid a dead Nissan Leaf after taking a long trip

While you cannot "Brick" a Nissan Leaf, it can become dead if you're away for a couple weeks, fortunately it's easy to revivify a dead Leaf, and it's easy to avoid the problem in the first place.

While you cannot "brick" a Nissan Leaf, that electric car can be rendered dead if the 12 volt accessory battery runs down. A member of the MyNissanLeaf forum found this out the hard way. He'd left his Leaf plugged in to a charging station and left on a long trip, only to return to find his car "totally dead". After a "jump start" the battery pack was full, which leaves us puzzling over why a Leaf can appear dead with a full battery pack. Fortunately there is a simple answer, some advice on what to do if this happens to you, and how to avoid the problem in the first place.

The condition of the Nissan Leaf in question was described as "totally dead, locks won't made any sound when pushing the button, when I turned the lights on (inside) I did not see even a glimmer on the filament." How this came about is as simple as leaving the car plugged in to a charging station, and leaving on a 2 week trip to Hawaii. It's got to be a fairly attractive idea to leave the car plugged in to a charger, because that will keep the cars battery pack topped up. But this turns out to be a bad idea. As several people noted on the MyNissanLeaf forum, when the car is plugged in to a charging station it does not maintain the voltage of the 12 volt accessory battery, and that battery eventually runs down.

The 12 volt accessory battery on any electric car assists in running the 12 volt system. The 12 volt system controls the lights, information, and other systems, including the control circuits that allow the car to turn on. In other words, it's nearly the role as the 12 volt lead acid battery on a gasoline car. On an electric car the 12 volt accessory battery is not recharged by an "alternator" but by a DC-DC converter powered from the battery pack. DC-DC converters take battery pack voltage and produce the 12-13.2 volts required to run that part of the car. If the DC-DC converter is disconnected from the 12 volt battery, it will eventually run down.

The fix, if this happens to you, is to do a jump start. It's just like any jump start you've done with a gasoline powered car. Pull out your jumper cables, connect the black cable to the frame of each car, and connect the red cable to the positive terminal of the 12 volt battery in each car. This will bring 12 volts to the car, letting the 12 volt system turn back on. You may need to leave the cars connected long enough to recharge the 12 volt battery, but it will probably be enough to get the car turned on and from there the DC-DC converter should take care of recharging the 12 volt battery. A 12 volt automotive battery charger can also be used to jump start, because what's required is to recharge the 12 volt battery.

What's better is to avoid the problem in the first place. That is as simple as not plugging the Nissan Leaf in to a charging station if you're away for awhile. If it is a long trip you should disconnect the 12 volt battery, or connect a "battery tender" style charger to the 12 volt battery. As we noted a couple months ago, the Nissan Leaf can sit idle, and not plugged in, for a long time with no risk of damaging the battery pack.

However this is not a universal recommendation. When we covered the risk of "bricking' a Tesla Roadster we learned that Tesla's recommendation is, while on a long trip, to leave the Tesla Roadster plugged in, to keep the battery pack topped up and not risk being damaged. The universal recommendation, then, is to study the specific needs of your car, starting with the contents of the owners manual.

You can read all the details on the mynissanleaf forum.

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Lol. I kiss my Prius every day when I climb into it.
The good thing about electric vehicles is that we will be able to kiss goodbye to self interested Texans in politics. This article is BS by a ludite petrol head. Was it Kin Canute [the wise] who commanded the waves to stop rolling up on the shore? Keep trying boys.
Would it then surprise you that I, the writer of this article, have built several electric conversions of everything from bicycles to a car, and do not own a gasoline car? What is Luddite about recognizing and discussing design problems? Nothing in this article is the equivalent to destroying electric vehicles.
So the 12v battery pack wasn't kept charged because the 12vDc converter was turned off because the main battery was plugged in to a charger? Surely the solution then is to disconnect it from the charger and the converter will then recharge the 12v battery?
Right - that's essentially what I said. However, that advice only holds for the Nissan Leaf, as the article says the other cars require different treatment.
actually you will still have to supply 12 volts dc by jumping or using a battery booster pack or charger as thelectronics for the dc to dc converter is controlled by the dead battery it seems that a software update that would monitor the 12 volt battery charge state and periodically turn on the dc to dc convertor to keep it topped of would be a wise workaround for that hopefully they do not need to make any modification to the electronics for that to be accomplished
Thanks for that information. I had no idea the LEAF was susceptible to this problem when plugged in.
I think there is something fishy in this article... I have NEVER had a 12 volt battery fail after 2 weeks sitting idle, not on my 2011 Nissan LEAF or any of the dozen other gas powered cars i have owned... Not even after 4 weeks have I ever had a 12 volt battery fail. Granted, maybe this article was based on a fluke situaion for this particular LEAF)... 100+ degrees for over 1 week straight.... Left something on that drained the battiers, etc. But i sincerely doubt anyone that owns a LEAF needs to worry about anything this article states. When gone for more than a few days, keep your LEAF plugged in and fhat will be fine in 99% of cases.
Leaf owners have to worry about leaving their car idle more than few days, for example weeks ... like me ... left for 5 weeks to Europe and didn't want to come back to a dead battery which was happening with my Prius if I forgot to unplug the 12v battery ... this time thanks to this article I did not leave the main battery plugged in and instead of leaving the car in my garage, I left it outside under the South Cal summer sun and when I came back the main battery of course was almost where I left it but more interesting the 12v battery was too: thanks to the sun and the solar panel, didn't have to unplug the 12 v battery during these 5 weeks and re-enter all the info that would have been lost ... had just to push the start button and drive ... wonderful !!
I do this at DIA: Turn your charge timer and climate control timers ON. The car turns "on" briefly and this keeps the accessory battery topped-up daily while you are away.
Thanks for the advice. This has just happened to me. Dealer was a zero so far as advice as they should be telling persons to this when they call into service with the "dead" car problem. The problem and solution here as stated by author is correct. This info should be out there and appreciate the author for getting the word out. Don't understand the vitriol about some commenters - this is certainly a problem which dealer and service departments should be ready to advise on. I can assure you they are NOT!!!
Can a booster battery be used to jump start a dead Leaf? For peace of mind maybe I should keep a booster battery in my storage compartment when I park in the airport parking garage for a 5 week trip.
Does anyone know what the latest Leaf recall regarding the recalibration of the battery is all about?
is there a specific technical reason for accessory battery not being constantly connected to traction battery? This happen also in Renault Zoe and other electric cars. Why???
My 12 volt LEAF accessory battery fails regularly, when the car is not plugged in. I remove it and have the local Autozone recharge it when this happens. Once the battery is judged "bad" by the tester at Autozone, I return it to Nissan for free warranty replacement. I have yet to determine the underlying cause of this problem. Perhaps a defective DC-DC converter? The car is 5 years old. The accessory battery fails once a year on average, and is judged defective after 2-3 fails.
Yes I have seen the same in my 2013 LEAF, and have replaced the 12 volt battery four times in 7 years. The helper (also at Autozone) suggested there may be something wrong with the way the car is treating the battery, causing them to fail over time.