Which battery dies first when leaving the car on?

[Wennfred]

I got my new Nokian Entyres today and while at this shop they sold Interstate Batteries so I inquired about those types, he stated that Interstate Batteries were the best with free replacement within 30 months if they go bad. Not sure if he was blowing air up you know what but I think it's time to do some research on the best 12v battery this year. I will probably replace mine this come March.




Fred

 

[RegGuheert]

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

IMO, this is the main issue with the LEAF 12V battery charging systems. Every other vehicle I have ever owned keeps the battery at 14.4V while the car is driving, ensuring the 12V battery is always topped off. This results in battery life of around 7 years where I live. But the LEAF only holds the voltage at 14.4V for a little while, then moves to a float voltage around 13.1V. When at the float voltage, the 12V battery does not get charged.

My observations tell me that the LEAF's 12V battery spends its time at around 50% SOC. That's not good for a lead-acid battery.

 

[Wennfred]

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

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 wonder if it's more so with Leafs without the Solar Panel option?


Fred

 

[RegGuheert]

I wonder if it's more so with Leafs without the Solar Panel option?

I doubt it. There have been reports of SL LEAFs with the solar panel having their 12V batteries go dead WHILE SITTING OUT IN THE SUN!

IMO, that thing is not much beyond a gimmick. I'm a bit tired of answering well-intentioned questions from people who are trying to learn more about the car.

 

[voganni]

I bought a accessory plug voltmeter for my 2013. Most of the time the car starts out at 14.v volts, then drops to 12.9-13.1 and stays there. Occasionally however, it will go to 14.4v and stay there for a long time, up to an hour. So maybe the car does know when to top up the battery more. I do agree though, running at a constant 14.4v would seem better to me.

Please let us know what the dealer finds out! I wish I could have made it to the dealer last Thurs. My car was in drain mode and they could have seen it in the act. Next time it freaks out, which will probably be in a couple weeks, I will get it down there. This issue needs to get addressed.

I'm not buying the "double push" reason for battery drain. I know I've never done it. In acc mode, the owner's manual states clearly that the car will turn everything off, including the stereo, within one hour. If you left it on in "on" mode, that would be pretty obvious since dash would be lit up.

I leased my 2013 on July 19. Since then it has run the battery dead twice, and attempted it 4 additional times. When it happens, the "dark" current goes from a normal 125ma to a whopping 980ma (almost an amp) and this will drain that little battery in less than two days. It seems to always begin after a charging session. The only way I can get it to stop is to disconnect the battery for a few minutes.

 

[TimLee]

After reading through the three pages, I think the OP (lion) has one of three things wrong: Either a defective 12V battery which can't hold a charge, or a problem with the charging hardware/software, or a problem similar to what voganni has been experiencing in which the current draw on the 12V battery either never dropped to the "dark" current level of a normal 125ma or for some reason jumped back up to a high current draw, 980ma that voganni has seen or possibly something higher.
I don't think the vehicle could have been left in auxiliary mode, as it will shut down after 1 hour. Shouldn't leave the 12V dead unless was bad low to start with or has way too high a "darK" current draw.
Can't have been left in Ready mode, as the DC-DC converter would have been active and kept the 12V charged. Sitting in the parking lot for 12 hours in Ready mode would only drop the high voltage battery maybe one, or two status of charge bar while just powering normal ready mode and the DC-DC converter. (assuming HVAC is off, much faster drain with AC in hot weather of about 1 bar per 1/2 hour, heat in cold weather could drop 2 bars or more per hour)
I don't think it could have been in On mode either. Although the DC-DC converter isn't initiailly active in On mode, the system does monitor the 12V battery voltage and periodically engage the DC-DC converter to recharge the 12V periodically. This isn't nearly as good as being in Ready mode from a standpoint of properly maintaining the 12V battery, but it should not leave it dead. But it will shorten the 12V battery life a lot if you do that a lot, which I did for the first two years of owning LEAF. 12V battery had to be replaced under warranty at no cost at two year battery test.
If I was the OP I would not trust the 12V battery. Need to monitor it carefully and monitor the "darK" current draw like voganni has been doing.
There have been lots of problems with 12V dead batteries in LEAFs. But Ingineer did report in this thread http://www.mynissanleaf.com/viewtopic.php?f=30&t=10775&p=247882&hilit=12V#p247882" onclick="window.open(this.href);return false; the following:

Let me clarify a few things: You can't accurately assess the SoC and health of a lead-acid battery solely by measuring voltage. There are many factors, such the exact chemistry variation, electrolyte stratification, plate sulfation, separator type, temperature, etc.

The Leaf has a proper temperature-compensated current-monitoring multi-stage charging system. The voltage will vary depending on many factors, but should be at least 13 volts anytime the Leaf is in READY mode (Green car icon on dash lit). If it is below 11 volts when the car is off, you have a problem. My 2011 is treating the battery properly in my opinion. Sounds like Oscar had a battery with a bad cell.

So on his 2011, he thinks the DC-DC 12V battery charging software is OK when in Ready mode.
But in Off mode the LEAF has experienced a lot of problems. The most significant when people leave the LEAF plugged in for lengthy times and the current drain is so high in that mode that the 12V battery can end up dead in just a few short days.
I wish lion and voganni the best of luck in getting to the bottom of their 12V battery drain problems. But Nissan service department saying you did something wrong (double pushed) is probably not correct. It is something wrong with one of the three things I noted at the top.

 

[voganni]

Excellent post TimLee! Fortunately my dealer service supervisor is very concerned and wants to see my car, and will open a tech case on it if they can't figure it out. It's a hassle for me to get it down there, but I will. I really want to get to the bottom of this, and I'm quite certain it is the root cause of many other Leaf owners' battery problems.

I tried leaving my car in "on" mode until it began charging the 12v battery one time, but when it got down to 11.5v or so I quit. At what voltage does it start? It would have to close the main contactors to turn on the DC-DC converter as I understand it.

 

[TimLee]

I tried leaving my car in "on" mode until it began charging the 12v battery one time, but when it got down to 11.5v or so I quit. At what voltage does it start? It would have to close the main contactors to turn on the DC-DC converter as I understand it.

I never measured the voltage to find out.
It does close the main contactor, at least on my 2011 LEAF that has a fairly low VIN manufactured the day before the catastrophic tsunami.
It clearly waits too long though, and doesn't go to high enough voltage long enough in ON mode to properly charge the 12V. It is basically cycling it too low and never really getting it recharged properly.
I have some reservations about how well it charges even in Ready mode. But Phil says he considers it OK on what he has measured on his 2011.

 

[lion]

I've been monitoring my battery all day (using the LeafDD display), and the voltage is 12.9 on average. Once in a while, I see 14.1, not sure what the pattern is yet.

That said, everytime I try to turn on the car, and start pushing the brake, it feels like the brake scrapes/hits something until the car turns on completely. This didn't start until the day of the battery failure, and I'm not sure what to do about it. The car seems to run fine otherwise.

Has anyone left the car on in ACC mode to see how long it runs before shutting down, to see if there is a working safety/cut-off mechanism in place?

 

[TimLee]

That said, everytime I try to turn on the car, and start pushing the brake, it feels like the brake scrapes/hits something until the car turns on completely. This didn't start until the day of the battery failure, and I'm not sure what to do about it. The car seems to run fine otherwise.

Has anyone left the car on in ACC mode to see how long it runs before shutting down, to see if there is a working safety/cut-off mechanism in place?

I have not validated the duration it will stay on in ACC. There really is no good reason for an electric vehicle like the LEAF to have an ACC mode that depends only on the 12V battery with no back-up from the DC-DC converter, so I never use it.
I hardly use On mode anymore either because of the adverse effect on the 12V battery. Mostly use Ready, but with caution to make sure it is Park and the Emergency Brake is double engaged (2011 with the electric parking brake).
Strange brake behaviour is a bit troubling. The other thread I referenced was about very bad brake behaviour when the 12V battery voltage is low.

 

[voganni]

Someone else made a post I read saying they were listening to the radio in ACC mode and it shut off in 1 hour. I haven't tested this. I'm also of the opinion now that ACC and ON modes should be avoided. At one point I thought my large "dark" drain was happening when powering down from ON mode. Not really sure of anything anymore, other than it's my only major complaint about the car.

 

[lion]

Ok, now things are just getting weird.

I changed the car settings so I could charge to 100% this morning, and several minutes ago, I walked into my garage, and noticed my damn lights are still on (so they have been on for hours). 12V battery voltage is still good tho, maybe because it was charging? I went to check the car out, and the lights are configured to 'Auto', so it should have turned them off.

After doing some testing, and even changing the delay to 0 seconds, it seems to do this in every scenario, so I'm guessing something is wrong with the photocell or the timer software.

I verified the car was completely shut down (while the lights were still on) by checking if my Dashcam had power, or if I could do anything else. Once I turn the lights off, and set it back to Auto (all while the car is still off), the lights stay off.

I'm wondering how long the 12V battery could power those LED headlights, and if this is what caused my problems several days ago.

I also verified the car was not in ACC mode.

Car locking behavior is different from before as well. When I unlock the car with the door button, it locks all my doors again ~60 seconds later. It does this even with the keys inside the car or the door open! I find it hard to believe this is normal behavior, so please confirm if my car is going bonkers

None of this was happening before, so I'm not sure what's going on.

 

[voganni]

Lion, you may need the services of a priest! The car is never supposed to be able to be locked with the fob inside. I've tried it, and it refuses. I don't have automatic headlights, but my headlights turn off in 45 seconds if I leave them on.

I suggest disconnecting the battery's negative cable for a few minutes and then reconnecting. You'll have to reset everything of course, startup sounds, timers, radio presets, clock, window auto-up preference, etc. I've had to do it so many times I made up a card listing how to get things back the way I like. If that doesn't return it to normal, you may have a computer issue. When my Leaf ran it's battery nearly dead, several failure modes were present when I got it back up. Brake failure light, powertrain failure light, maybe one more. I had to disconnect the battery to get them to go away. The car would not go into drive until I did. Good Luck!

 

[planet4ever]

When multiple electrical things start behaving erratically or out of spec the one common factor is the power source. I think your 12v battery is bad. In the first place, a voltage test alone is not enough. In the second, you can't even test voltage reliably without disconnecting the battery, since you never know when the computer is going to decide to start charging it. If the 12v battery is being charged you obviously aren't testing the battery voltage, but the charging circuit voltage.

Ray

 

[lion]

I do think there is a 12V problem, just like you said. There are 2 ways of testing in my scenario. Using the LeafDD, I can read the battery voltage reported by the car, and then we have the dealer, which did load-test the battery.

This morning, it failed to preheat the car due to cell reception problems supposedly (never happened before). Brakes still feel weird when starting the car.

I don't know if all these problems are because of something gone wrong during their load-test/checkup (unlikely), or if my initial dead 12V battery was caused by the same problem causing my current issues (more likely, but weird).

Either way, I'm bringing it in, just need to figure out when.

 

[TimLee]

Car locking behavior is different from before as well. When I unlock the car with the door button, it locks all my doors again ~60 seconds later. It does this even with the keys inside the car or the door open! I find it hard to believe this is normal behavior, so please confirm if my car is going bonkers

None of this was happening before, so I'm not sure what's going on.

Are you sure the vehicle was Off when the auto door locking occurred after ~60 seconds?
There is a setting to have the doors auto lock, but it should only happen when the vehicle is in Ready mode. And I think it only does the auto locking after the vehicle is in Drive for some period of time.
If it is doing this with the LEAF being off, something is messed up in the smart start hardware or software that is acting as if the vehicle is in Ready mode even though it is Off.

 

[JohnP]

I took my 2011 SL in for a 2 ½ year service and asked the dealer to check the battery. They came back and said the 12v needed a charge as it was only 1/2 charged. They said I was not charging or using the car enough to completely charge both batteries. I told them that my commute to work is 44 miles round trip 5 days a week and I charge to 80% every night. The service managers asked why was I doing that and recommended I charge to 100% once in a while. Seems strange since Nissan recommends only charging to 80% to extend the life of the battery. They now what to have me come back so they can put a charger on the 12v to see if the battery will fully charge. Sounds like there is something wrong with either the battery or the charging system. Any ideas?

 

[RegGuheert]

I took my 2011 SL in for a 2 ½ year service and asked the dealer to check the battery. They came back and said the 12v needed a charge as it was only 1/2 charged. They said I was not charging or using the car enough to completely charge both batteries. I told them that my commute to work is 44 miles round trip 5 days a week and I charge to 80% every night. The service managers asked why was I doing that and recommended I charge to 100% once in a while. Seems strange since Nissan recommends only charging to 80% to extend the life of the battery. They now what to have me come back so they can put a charger on the 12v to see if the battery will fully charge. Sounds like there is something wrong with either the battery or the charging system. Any ideas?

You are doing nothing wrong. LEAFs typically maintain the battery at a little over 50% charge. As a result of this deficiency, we can expect a large number of premature 12V battery failures.

One thing you CAN do is charge your LEAF battery to full using a high-quality battery maintainer. If you do this every couple of weeks, you will likely get more life out of your battery.

 

[DarkStar]

I took my 2011 SL in for a 2 ½ year service and asked the dealer to check the battery. They came back and said the 12v needed a charge as it was only 1/2 charged. They said I was not charging or using the car enough to completely charge both batteries. I told them that my commute to work is 44 miles round trip 5 days a week and I charge to 80% every night. The service managers asked why was I doing that and recommended I charge to 100% once in a while. Seems strange since Nissan recommends only charging to 80% to extend the life of the battery. They now what to have me come back so they can put a charger on the 12v to see if the battery will fully charge. Sounds like there is something wrong with either the battery or the charging system. Any ideas?

A 100% charge on the traction battery wouldn't have anything to do with the 12v battery.

 

[lion]

Car locking behavior is different from before as well. When I unlock the car with the door button, it locks all my doors again ~60 seconds later. It does this even with the keys inside the car or the door open! I find it hard to believe this is normal behavior, so please confirm if my car is going bonkers

None of this was happening before, so I'm not sure what's going on.

Are you sure the vehicle was Off when the auto door locking occurred after ~60 seconds?
There is a setting to have the doors auto lock, but it should only happen when the vehicle is in Ready mode. And I think it only does the auto locking after the vehicle is in Drive for some period of time.
If it is doing this with the LEAF being off, something is messed up in the smart start hardware or software that is acting as if the vehicle is in Ready mode even though it is Off.

Yep, very sure it's turned off. In fact, I checked if the button makes a sound when you do hit it twice by accident when turning the car off, and you do hear 2 dings. My dash cam and other accessories were also turned off, so unless there is a 'stealth' mode, pretty sure it was off.

I'd still love to hear from anyone who has experienced 12V issues about the way the brake pedal felt when starting the car.