Which battery dies first when leaving the car on?

Nissan LEAF folks have insinuated that I left my car running all day, and that's the reason my 12V battery was dead. However, I am 100% sure I did shut it down for various reasons.

So now I'm wondering. I was under the impression that if I leave the car running, it will stay online until the traction pack is depleted. Is my assumption wrong? As long as the car is on, does it not charge the 12V battery?

This is assuming I don't have a defective 12V battery which can't hold a charge, and that there isn't a problem with the charging hardware/software.

See my other thread in this subforum for details, but in short, I had ~60+ miles range left after I boosted the car's 12V battery (which reported @ 5V according to my LeafDD unit).

Thoughts?

No, I believe you to be correct. As long as the car is on and in ready, the 12 volt inverter is charging the 12 volt battery.

lion said:

I was under the impression that if I leave the car running, it will stay online until the traction pack is depleted. Is my assumption wrong?

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That's what I thought, so that would confirm I didn't leave the car on, since the range # matched what I saw when I exited the car yesterday morning. It sounds like I'm dealing with a defect of some kind, but Nissan LEAF customer service told me that unless they find something obvious, they will just charge the battery, and nothing else.

If you just leave a Leaf turned on sitting, what happens, does it eventually turtle and shut down?

lion said:

That's what I thought, so that would confirm I didn't leave the car on, since the range # matched what I saw when I exited the car yesterday morning. It sounds like I'm dealing with a defect of some kind, but Nissan LEAF customer service told me that unless they find something obvious, they will just charge the battery, and nothing else.

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It sounds like your DC to DC converter is not properly charging the 12v battery, but it also sounds like you have a horrible dealer. If you really like them, you can try again and ask them to specifically ask them to check this, but this should have been what they checked when you brought them the car and complained that the 12v battery keeps dying. You might try another dealer who has a better Leaf Tech, or make sure you have your dealers' best Leaf tech perform the checkup on your car. It is possible that when you brought the car in the best tech was on his day off.

You could have left the car on in accessory mode. That would run down the 12 volt battery without running the DC to DC converter.

Once the pack depletes sufficently, yes.

LTLFTcomposite said:

If you just leave a Leaf turned on sitting, what happens, does it eventually turtle and shut down?

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Wouldn't that require 2 button pushes (each push being very audible)? The headlights turned off after 45 seconds or so (in AUTO), wouldn't those stay on as well in ACC mode?

I'm also surprised that the LEAF doesn't have a low voltage cut-off, where it shuts down if the 12V battery gets too low. Even my 10 year old cars had this feature.

palmermd said:

lion said:

That's what I thought, so that would confirm I didn't leave the car on, since the range # matched what I saw when I exited the car yesterday morning. It sounds like I'm dealing with a defect of some kind, but Nissan LEAF customer service told me that unless they find something obvious, they will just charge the battery, and nothing else.

Click to expand...

It sounds like your DC to DC converter is not properly charging the 12v battery, but it also sounds like you have a horrible dealer. If you really like them, you can try again and ask them to specifically ask them to check this, but this should have been what they checked when you brought them the car and complained that the 12v battery keeps dying. You might try another dealer who has a better Leaf Tech, or make sure you have your dealers' best Leaf tech perform the checkup on your car. It is possible that when you brought the car in the best tech was on his day off.

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Well I haven't heard back from the dealer. It was the Nissan LEAF folks who told me that I should make sure to turn the car off in the future, and made it sound like it was my error. I WANT it to be my error, because that means nothing is wrong with the car, and I don't have to worry about this, but I'm

Just FYI from the user manual:

CHARGING THE 12-VOLT BATTERY

The 12-volt battery is charged automatically
using electricity stored in the Li-ion battery.
When the 12-volt battery is being charged, the
charge status indicator light on the instrument
panel flashes. (except when charging the Li-ion
battery or the power switch is in the READY to
drive position.) See “Charging status indicator
lights” in the “CH. Charging” section.


While vehicle is in use

The Li-ion battery charges the 12-volt battery as
necessary when the power switch is in the
READY to drive position or ON position.
The 12-volt battery is not charged in the
following conditions.
. When the power switch is in ACC position.
. When the power switch is in ON position
and shift position is in the N (Neutal)
position.


While the vehicle is not in use

When the EV (Electric Vehicle) system is off for
an extended time, the 12-volt battery may be
automatically charged for a short period of time
on a regular basis.

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Also, you would not be able to charge the main pack if you leave the car in the ON position (I'm not sure about ACC. I know you can put it into ACC when charging, but not sure if you can start with it there). The 12v should also be getting charged when the main pack is getting charged. If you are not showing something over 12v when charging the main pack or when the car is in "Ready" mode, then I think you need to look at the 12v charging system. If it is charging in these conditions and it is still drawing it down when you turn it off then there is something getting stuck on when you try to turn the car off. Either way, the tech should be able to trace this down.

I think the LEAF folks told me it charges every 5 days or so, for a very short time.

I guess I need to watch my LeafDD even closer now (I usually take pics, but don't process the data until the weekend or so).

Still waiting for the dealer to call me back, so we'll see, I'll report back once I hear from them.

lion said:

Wouldn't that require 2 button pushes (each push being very audible)? The headlights turned off after 45 seconds or so (in AUTO), wouldn't those stay on as well in ACC mode?

I'm also surprised that the LEAF doesn't have a low voltage cut-off, where it shuts down if the 12V battery gets too low. Even my 10 year old cars had this feature.

Well I haven't heard back from the dealer. It was the Nissan LEAF folks who told me that I should make sure to turn the car off in the future, and made it sound like it was my error. I WANT it to be my error, because that means nothing is wrong with the car, and I don't have to worry about this, but I'm

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No, if you accidentally bounce your finger for a double press, you don't hear 2 beeps (at least I don't think you do). Everything on the dash including the entertainment system goes dark, and there is no indication that the car is in accessory mode for several seconds. I recently did a double press accidentally, and just sat there and waited until the display came up so I could turn the car off. It took what seemed like forever to see any indication of life. I actually started to doubt that I had actually double pressed it, and was thinking about getting out. The headlights might stay on rather than turning off in 45 seconds, but I don't hang around for long enough to find out. Actually, I don't know if the headlights stay on in accessory mode and auto.

Here is a post where I spelled out all the possible transitions by pressing the power button once or twice, and also defined the differences between ACC and ON modes. (Many people think of ON mode, as opposed to READY mode, as being ACC mode.)

http://www.mynissanleaf.com/viewtopic.php?f=30&t=12066&start=34

As palmermd's quote from the User Manual says, the 12v battery is not charged if the car is in ACC mode, and as DanBaldwin says, an accidental bounce when turning the power off can take it directly from READY to ACC with an intermediate all-black period. From my table you can see that that happens if the brake is not depressed. If you depress the brake when turning it off, the accidental bounce will take it directly to ON. For this reason I recommend pressing the brake when powering off. This is even more important in the 2013 S model I now have, since the center console (such as it is) is mostly black even when in ACC, ON, or READY unless the audio system is in use. If you have turned off the on-screen clock it will be totally black.

Ray

DanBaldwin said:

lion said:

Wouldn't that require 2 button pushes (each push being very audible)? The headlights turned off after 45 seconds or so (in AUTO), wouldn't those stay on as well in ACC mode?

I'm also surprised that the LEAF doesn't have a low voltage cut-off, where it shuts down if the 12V battery gets too low. Even my 10 year old cars had this feature.

Well I haven't heard back from the dealer. It was the Nissan LEAF folks who told me that I should make sure to turn the car off in the future, and made it sound like it was my error. I WANT it to be my error, because that means nothing is wrong with the car, and I don't have to worry about this, but I'm

Click to expand...

No, if you accidentally bounce your finger for a double press, you don't hear 2 beeps (at least I don't think you do). Everything on the dash including the entertainment system goes dark, and there is no indication that the car is in accessory mode for several seconds. I recently did a double press accidentally, and just sat there and waited until the display came up so I could turn the car off. It took what seemed like forever to see any indication of life. I actually started to doubt that I had actually double pressed it, and was thinking about getting out. The headlights might stay on rather than turning off in 45 seconds, but I don't hang around for long enough to find out. Actually, I don't know if the headlights stay on in accessory mode and auto.

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I'll have to do some testing, but I also have a dashcam which plays a little music when it shuts down (plugged into the cig lighter), and I'm do recall hearing it when I shut the car off, because it's so dang loud.

lion said:

... Nissan LEAF customer service told me that unless they find something obvious, they will just charge the battery, and nothing else.

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At the very least, the battery needs to be load tested. Running a conventional 12V flat diminishes its capacity, sometimes severely. 5V is basically flat.

If it's been run down multiple times it could be very weak by now, to the point where even normal "dark current" drain could run it low quickly.

So, a healthy battery is the first order of business. How many times have you had the 12V go dead on this car?

lion said:

I'll have to do some testing, but I also have a dashcam which plays a little music when it shuts down (plugged into the cig lighter), and I'm do recall hearing it when I shut the car off, because it's so dang loud.

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You would hear that on a bounce, because the car shuts completely down and then reboots.

Ray

DanBaldwin said:

No, if you accidentally bounce your finger for a double press, you don't hear 2 beeps (at least I don't think you do). Everything on the dash including the entertainment system goes dark, and there is no indication that the car is in accessory mode for several seconds. I recently did a double press accidentally, and just sat there and waited until the display came up so I could turn the car off. It took what seemed like forever to see any indication of life. I actually started to doubt that I had actually double pressed it, and was thinking about getting out.

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Given the number of people that have fried their 12 volt battery, I don't know why Nissan doesn't fix this problem. It shouldn't be easy to accidentally run your 12 volt battery into the ground, thus grounding your Leaf until the 12 volt battery is charged. A serious design defect.

I have once left car in READY mode (with lights on) in garage for 15 hours. It just used 3 bars of main battery and stayed alive.

From what I've been reading in this forum, there has been quite a few 12v dead batteries coming off the 2013's

Fred

FYI, my dashcam also plays a chime when booting up, which I did not hear.

I got the car back, and it looks like they load tested the battery. Before charge, it was halfway on the scale of how healthy it was (meaning borderline dead), after charge, it was 75% or so. I didn't get to keep that documentation, in hindsight, I should have taken a pic.

That said, when I picked up the car and started it up, the brakes felt weird again (feeling a clunk/notch halfway down, might be part of the ABS). It's difficult to describe, but the only other time I experienced this was yesterday.

The battery is reporting 12.9V while driving, but will watch it.

The LEAF tech was out on a test drive, so I couldn't ask him questions directly, and they were busy as hell.

I don't feel confident about this situation, but both the dealer and the LEAF customer service guys seem to think everything checks out.

Wennfred said:

From what I've been reading in this forum, there has been quite a few 12v dead batteries coming off the 2013's

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Agreed. But please note it is not just the 2013s. The 2011/2012s also seemed to suffer the same fate. Personally, I do not think the 12V charging system in the LEAF is doing a good job of keeping these batteries alive. I've always found that somewhat ironic given how advanced the HV battery charging system in the LEAF is.