How to get moving if your 12v battery is dead (ZE1)

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Astral

Well-known member
Joined
Mar 15, 2023
Messages
73
Hi all, I am new to being a Nissan Leaf owner but my friend has had one for years so I am well informed in general about the car. I own a ZE1 2018 model. I am writing this because recently (after 4 years) the original battery for my friend (also ZE1 2018 model) had died and mine is still alive but base voltage is about 12.1v so not that strong it would seem.

Anyway, his battery left him stranded and he solved it by getting a new one the next day. Unfortunately he was on a trip so he had to pay an extra night in the hotel. Later I have stumbled upon a trick that was presented for a different EV model and I was wondering if the same was true for the Leaf.

Apparently, when the battery is not good enough to power on the vehicle, you can send a signal over your phone to start climate control remotely. Doing that will automatically engage the DC DC charging and your battery should go up in voltage, thus allowing you to start the car and keep going.

I presume this could be possible if the battery is not completely shot but the voltage dropped below a certain threshold (don't know what that is exactly). I also don't know if the remote climate control would engage at all if battery voltage is not sufficient to start the car.

Maybe somebody has had some encounter with this and could share more.

Thanks!
 
Never heard of that but it will be very useful if that is possible and could serve as a reserve just in case.
 
I've read it, but can't confirm it. The big question is, as noted, how well a near-dead battery can close the big DC contactors to power the climate control. The trick that we use to start these cars is to carry a little portable battery powered "jumpstarter".
 
Thanks for your input. The problem with a jumpstarter is that the price of it is basically the same or sometimes even more than a brand new 12V battery. Do you have any recommendation what is the "lowest" spec one that could get the job done? And then there is the issue that you have to keep the jumpstarter in a good shape. Not sure how much maintenance this requires, putting it on a charger every 2-3 months?
 
If it isn't used, then it's more like every six to nine months, for the lithium versions. And while they used to cost as much as a car battery, car battery prices have skyrocketed. Any jump starter than can start an ICE vehicle can start a Leaf, as much less power is required.
 
Where I live a really good 12v battery is under 80 dollars. For this I can buy an entry level jump starter. So maybe this is region specific. But it doesn't make much sense for me.
 
I do have a ~$50 lithium jump starter but truthfully haven't had to use it as I purchased a new 12v battery about the same time and all has been well. I kind of agree with you about the maintenance of such things, if you don't keep it charged it won't do you much good. My Lithium seems to be barely discharged when I check it every 6 months or so but the Pb one I had before would seem to be almost dead every 3 months or so and was actually dead when I needed it, before getting the new 12v and Lithium jump starter.
Unfortunately, jump starters aren't a get-it-and-forget-it thing, it does take some maintenance and I'd imagine the Li batteries fail after a while(maybe 5 years??) I know the old Pb ones were lucky to get 4 years so there's that.
Honestly, I think the best thing might be a set of decent-quality jumper cables. They are indeed a get-it-and-forget-it thing and never need maintenance, you just need someone with a car to be around and willing to let you use their car to jump it. And when I say decent quality I don't mean you need a 4g cable, really anything will probably suffice, 10 gauge? but I wouldn't get a real cheap set with cheap flimsy ends, I'd expect to pay around $30?? but again should last your lifetime if taken care of.

Note jump starting isn't as easy as it once was as many of the new, particularly hybrid cars make it kind of hard to access the battery or top of the battery to attach your jumper cables. I know to access the jumper posts?? on our '07 Prius and even '22 Rav4 Prime you have to remove a rather large plastic electrical box cover to get to the metal thing you attach the jumper cables to. Hopefully, the person you'd get a jump from would have an older non-hybrid car where you can directly attach to the top of the battery but again it is possible to use a hybrid, you just might have to work at it harder and have someone willing to let you kind of disassemble things on their complex possibly $50k+ vehicle!
Interesting idea about turning on your cars remote climate control in this case, might work as it's possible the climate control relay/contactor might take less current than the traction batteries contactor but as noted the battery would have to have at least some juice, not totally dead.
 
The Gen III Prius has two little lead posts in the engine compartment, under a small cover in one of the electrical boxes there, connected to the 12 volt battery in back. Ironically, it would be easier to use those with small gauge alligator clamps.
 
LeftieBiker said:
The Gen III Prius has two little lead posts in the engine compartment, under a small cover in one of the electrical boxes there, connected to the 12 volt battery in back. Ironically, it would be easier to use those with small gauge alligator clamps.

Yes sounds like our '07 but the cover isn't particularly small and is hard to pop open it's 3 tabs even on a warm day, in the cold, it can be a bear. As I also trickle charge the Prius I've opened and closed the cover many times so it's finally getting easy to open but I'd never leave it off for water. I remember the first time I had to take it off in the bitter cold and I was cussing the Japanese engineer that thought such a thing was a good idea but then again they probably don't get the bitter cold where the Prius was designed :lol:
 
Astral said:
Apparently, when the battery is not good enough to power on the vehicle, you can send a signal over your phone to start climate control remotely. Doing that will automatically engage the DC DC charging and your battery should go up in voltage, thus allowing you to start the car and keep going.
Sounds like wishful thinking.
Having said that, you can jump start a Leaf with a 12v drone/RC battery if it's got enough AHrs. I know--because I've done it.
 
I wouldn't use my Rav4 Prime to jump start another vehicle. Maybe I would if the other car was an EV but certainly not an ICE.

There are various opinions about this on the web but from what I can see, the official Toyota position is that this shouldn't be done.

https://www.toyota.com/owners/resources/warranty-owners-manuals.rav4-prime.2022.digital.om42e33u.ch08se020410 (see bottom)
 
Astral said:
How much is enough?

It takes roughly +184 watts (or less if using all LED lighting) of power for 2 seconds to start a Leaf.
Just about anything (portable jump start wise) can power up a Leaf. The portable Lithium jump-starters have more than enough power as they are designed to provide +1000 watts for an ICE to start.

Start Up Power Reference: https://mynissanleaf.com/viewtopic.php?t=32820&start=10
 
Astral said:
Apparently, when the battery is not good enough to power on the vehicle, you can send a signal over your phone to start climate control remotely. Doing that will automatically engage the DC DC charging and your battery should go up in voltage, thus allowing you to start the car and keep going.
There is an actual reason that supports this. If the 12V battery does not have enough power to start the Leaf using the key fob, it's possible that having the lights come on (cabin lights, brake lights, etc.) is just enough to make it NOT work.

Using a remote start signal can "start" the leaf without those additional loads and in a rare (I would call it) circumstance, this could possibly work. Again, this would be sheer luck that your 12V can start the Leaf without the lights load. :?
 
I have had times (once with 2011 and once with 2015) when the 12V battery was failing and the car would not start up in full ready mode. I tried turning off and back on several times and each actually started up enough to get the DC-DC converter active. This allowed the 12V battery to charge a little so that the next restart resulted in full ready to drive mode. I usually carry a lithium 12V booster pack in each vehicle now because they hold charge for a long time and 12V batteries fail suddenly in my climate. I have started V8 SUV's without incident with booster packs--better than jumper cables.
 
My Leaf warned me today that my key battery is low. I would imagine it should then also be able to tell when the 12V battery is low. But looks like most of the stories told by the owners is that the battery dies suddenly without any warning. Unfortunately.
 
I'm not sure if it matters but a SLA 12V battery is actually made up of 6 cells in series. I don't know of any car batteries that include external connections to the individual cells so there is no way to know the states of the individual cells until one completely fails.

The key fob battery is a single cell so it has a single voltage that can be read to indicate its state. It also isn't recharged so its life cycle is much simpler to track.
 
All my 12V battery problems went away when I disabled the data modem from the regular menu. There is poor cell service here and the modem tries all night and day to connect, and in about 48 hours the Leaf's 12V battery is dead. It still prompts me to enable the data. I always choose "No."

It was also a great help to wire a low-power weatherproof voltage monitor on top of the battery, so I could pop the hood and read the state of charge in a couple seconds. The downside is the voltage monitor is a slight constant drain and it will discharge the 12V battery in 30 days if the Leaf is not driven.

Harbor Freight had a nice jump starter on sale for $39, it's easy to keep it charged at home, it has been very handy! If you are electrically savvy, any typical 12V gel cell battery can "jump" the Leaf, but there are multiple safety issues associated with carrying and using a bare battery without any short-circuit protection or reverse-polarity protection.
 
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