Dead 12V Battery Overnight??

[Nubo]

With the plethora of 12 volt battery issues though, I suspect that maybe our batteries were ordered too far in advance by Nissan and were already sulfated when installed

That would be surprising, given today's Just-In-Time manufacturing techniques. On the other hand it does seem odd that there would be so many "defective" 12V batteries. I still suspect deep-cycling is at the root of many of these failures but then again we have people whose problems seem to have resolved after replacement.

Has anyone that has received a battery replacement taken any voltage readings after it has been in service to see how it compares to their old battery?

IIrc, after a year in service, my OEM battery was showing a resting voltage of 11.6 to 11.7. After not quite a year, its replacement rests between 12.4 and 12.5v.

I replaced with a unit purpose-built for deep-cycle storage duty in solar installations (Sun-Xtender 420T). Seemed appropriate. FWIW, the replacement actually sat in my garage for about 7 months before I finally installed it.

 

[lion]

Does the DC to DC charger only charge the 12V battery at the end of a 100% charging cycle?

Maybe that's the issue here? Everyone with 12V battery problems always charge to 80% ?

No, the DC/DC converter "charges" the 12V battery whenever the LEAF is charging or in READY mode (and intermittently under some other conditions). But I put the word "charge" in quotes since it typically spends too little time actually charging the battery (14.4V) to completely top off the battery, which is required for proper lead-acid battery health. Instead, the battery is normally held at "float" condition (13.1V), which neither charges nor discharges the battery. (Note that 13.1V *will* charge the battery if it is at a very low state-of-charge. That is why many of our batteries tend to sit around at about 60% SOC.)

I haven't had an issue yet (knock on wood) and draw a lot more current than most with my 1000 watt stereo but I charge to 100% at least 5 times a week.

No problem with the stereo. The DC/DC converter in the LEAF is extremely powerful, fast and accurate. As a result, it can hold the 12V battery wherever it wants to (unless the battery is shorted), even under heavy and varying loads. Unfortunately, I don't think it is programmed to produce output voltages that ensure good 12V battery health.

So my 12V battery died a month or so ago, and ever since, I've been dealing with a ghost in the machine.

Finally got my car back, and most of my problems were caused by a stuck door switch. They seem to think this is also what might have caused my 12V battery to drain , since my auto lights weren't functioning properly, and the tech mentioned that without this switch working properly, parts of the computer might still up and running.

I'm not sure what to believe, but definitely something to keep in mind.

When I tried jumping my car, it only stayed up and running for as long as my booster battery was hooked up. Once I killed the battery, everything died (still had 60+% on my tractio pack). You would think that once the computer has booted, the traction pack could start charging/powering the 12V battery & hardware (since it doesn't seem to do this, how can folks get away with hooking up an inverter to the 12V battery?).

 

[cliff]

since it doesn't seem to do this, how can folks get away with hooking up an inverter to the 12V battery?).

I also have been wondering about the use of an inverter. I saw a posting where a refrigerator was kept going
for 17 hours in only the "on" mode not the "ready" mode. The service manual makes it clear that no charging
will occur unless in "Park" while not in "Ready" mode. This no park would be hard to do, so not worried about that,
but it also says that no charging will occur for at least an hour after going to "On" mode. So I guess do not
heavily use an inverter for the 1st hour. But what happens after that hour when the charging starts?
Will it stay charging, or as I suspect cycle? And if it cycles, how often? Maybe just always use the
"Ready" mode, but how much additional power does this use? It would use power steering, and brakes,
but maybe not much else.

 

[RegGuheert]

since it doesn't seem to do this, how can folks get away with hooking up an inverter to the 12V battery?).

I also have been wondering about the use of an inverter. I saw a posting where a refrigerator was kept going
for 17 hours in only the "on" mode not the "ready" mode. The service manual makes it clear that no charging
will occur unless in "Park" while not in "Ready" mode. This no park would be hard to do, so not worried about that,
but it also says that no charging will occur for at least an hour after going to "On" mode. So I guess do not
heavily use an inverter for the 1st hour. But what happens after that hour when the charging starts?
Will it stay charging, or as I suspect cycle? And if it cycles, how often? Maybe just always use the
"Ready" mode, but how much additional power does this use? It would use power steering, and brakes,
but maybe not much else.

I was the one that posted about powering two refrigerators from the LEAF. It was definitely in READY mode and Park. If I said anything else, I misspoke.

 

[kevinleaf]

I have also had a dead 12v battery twice now. Very annoying.

This second time the traction battery was probably at 100% and the 12v still went dead. Plugged in and charging overnight did not bring the charge on the 12v battery back up. Last I checked it was at around 5v.

Both times I drained the 12v battery I had my ELM327 type OBD-2 reader plugged in overnight too. Not sure how this could pull enough to drain the 12v completely though.

I am taking it to Nissan tomorrow for a separate issue and I'll have them check the battery.

 

[RegGuheert]

Both times I drained the 12v battery I had my ELM327 type OBD-2 reader plugged in overnight too. Not sure how this could pull enough to drain the 12v completely though.

I find that if my Android phone is still in the LeafSpy app and it is sitting close enough to the garage, it will try to make measurements from the car, even if the car is unplugged. (When the LEAF is charging, it DOES make measurements.) Perhaps this drains the 12V battery.

 

[kevinleaf]

Nissan did say the battery had failed. They are replacing it. Certainly would not expect this with a new car with a new battery.

 

[maizester]

Hi there - I don't actually own a Leaf but a Coda, but noticed this thread because I've had a similar problem with my 12v battery running down to single digit voltage very quickly. An EV mechanic suggested grinding the paint away where the 12v battery negative cable is bolted to the chassis and doing the same where the DC to DC converter is grounded to the chassis.Without proper grounding, the electronics which keep the 12v battery properly charged from the high voltage pack can't function the way that it should.Since I did that last week, my 12v battery has stayed charged up.Hopefully the battery has some life left after being run down that far - cheers -DAve

 

[kevinleaf]

There seem to be some bad batteries in the 2013's. Don't totally freak out, just go to the dealer and get it replaced. No need to carry a spare. Since the replacement I haven't had a bit of problems and I routinely left my doors of the car open for 2 hours at a time while moving my stuff into a new house.

 

[Berlino]

I hadn't had any problems with my 12v battery before, but it went completely dead yesterday.

1) 15h00 Thursday: LEAF parked. As per the memory of LEAF Battery App, the 12v was at 14.4v. I have never calibrated the LEAF Battery app readings of the 12v, though.

2) 08h00 Friday: Ranged successfully checked by Carwings, but car not used.

3) 18h00 Friday: Attempts to use Carwings to pre-heat fail. Communication error with the vehicle.

4) 18h30, I go down to the car and the intelligent key doesn't work. Upon entering the vehicle with the old-fashioned key, it becomes apparent nothing works. Efforts to start the car by holding the fob close to the button fail.

5) 19h00 I call Nissan road-side assistance. They agree to tow the LEAF to a nearby dealership to "recharge the car." I stop them right there to say that the traction battery doesn't need to be recharged, but there is an issue with the 12v battery. They state that all battery issues require towing to dealerships. I request that the tow company notify me before arriving.

6)20h00 The flat-bed arrives. The driver asks me what the problem is and I answer that the 12v is dead. He asks if i want him to jump-start the car. I tell him I would be fine with that, but Nissan says that the vehicle needs to be towed to the dealership. There's no space in the lot for the flat-bed to back up to the front of the car. The LEAF would have to be dragged or pushed for a couple of car-lengths to be hoisted on the flat-bed, or put-in a proper tow position with the front-wheels off the road. The driver asks me if I can put the vehicle in neutral. I respond that the only way I know is by reestablishing power with a boost. He mentions that he doesn't have experience with electric cars and then spends five minutes on the phone. Afterwards, he states the he doesn't have the equipment for a boost (I believe he just had a more lucrative or pressing call to go to) and that another truck will have to come. However, the other unit is busy on a police call, so it will be at least an hour. Since the dealership closes at 21h00, the towing option was becoming less and less interesting.

7) I research this site (thanks mynissanleaf.com) and find instances of 12v problems. I also discover how to force the vehicle into neutral, but I'm sure the tow operator will have no idea how to do it. I also see that towing the car in reverse is bad. By this time, my neighbor who parks in front of me has probably returned, making reverse the only way to extract the LEAF from its spot.

8) 00h15 It has now been four hours and I receive a call from the tow company. The apologize for the delay, but say they were overwhelmed with calls. They note that I had requested notice to come down before they arrive and ask if it's because I need to provide the keys. I say, "no, it's because I want to make sure the car is in neutral before you tow it, but I've gone to bed and the dealership is closed, so I don't want service now. Can you come back tomorrow morning?" They agree to return the following morning.

9) 08h00 Saturday I call the tow-truck company to reschedule and they announce that they have already towed the vehicle to the dealership. I express that it is wrong because I had come to an agreement with the night dispatcher not to do that. They reply, "What's wrong, we were contracted to tow you to the dealership and that was accomplished." I explain that I had requested to be present before they towed, but they continued to think that it was normal, "the guy took the initiative to tow you without needing a key. We're busy, so we have to tow when we can." I go down to the lot to see if I can determine in what direction my LEAF was removed from its spot, but snow has fallen, covering much of the tracks.

10) The dealership is closed for the weekend. I don't see any upside to leaving the 12v discharged for another 48 hours, so I walk the 2 miles there and find my LEAF unlocked and outside the gates at which point I call a friend to boost the car.

11) The jump-start goes fine. As per advice in this forum, we left the cars connected for 20 minutes. After disconnecting them, I was able to power on and off without an issue. Just after starting the boost, LEAF Battery App reported 14.5v and was between 14.3v and 14.5v during the entire process. Is this because it was registering voltage coming from the other car's battery? After disconnecting the cables and driving home, it was at 14.4v.

As to how the battery drained in the first place, I am not sure. The interior lights were off. An adapter was plugged into the 12v, but that should be off when the LEAF is off. If I had left the car in "ON" or "READY" overnight, one of my neighbors who frequently walks his dog probably would have noticed the daytime running lights.

Naturally, I'm concerned there may be a problem with the battery. I am also worried that the LEAF was dragged backwards while in PARK.

 

[LeftieBiker]

I'm carrying a spare deep cycle battery and cables after my 12V failure, but it hasn't recurred. I top the battery up once a week now, with a battery charger/maintainer. In my case I don't think the battery was 100% dead. I think the 2013 at least has a 'preserve mode' that shuts the car down while the accessory battery still has enough juice to keep the logic memories alive. I believe that mine got drained because I was using the wheel heater, one seat heater (on Low)and a 4.5 amp heated throw blanket, all at once during frigid weather.

 

[GlennD]

I am part of the group with a bad battery.

I took it to the dealer and they said the battery was fine even though I had a voltmeter on it. They blamed my Ham radio that is totally controlled by a relay controlled by the acc buss. It draws no power with the car off.

Three days later it was totally dead after breakfast. Customer care towed me to the same dealer. The tow truck driver stated I had a bad battery.

Well, they replaced the battery under warranty but claimed it would not last due to my ham radio. The mechanics grasp at any straw to shift blame.

 

[Mmen]

Has this problem with charging the 12 v battery been fixed with the MY2014? I hope so, as I due to get mine soon.

 

[LeftieBiker]

Has this problem with charging the 12 v battery been fixed with the MY2014? I hope so, as I due to get mine soon.

I'd guess not. They've had several years to fix it, and the '13 model change year would have been the perfect time to, say, add a circuit that checks the 12V battery regularly and increases charging as needed. They didn't.

All you have to do, though, is add a hardwired connection for a battery maintainer. You connect one ring terminal (+) to the positive battery terminal, via the clamp bolt, and the other one to a nearby ground - NOT the negative terminal. The Diehard 2 amp maintainer/charger and the Battery Tender Jr. appear to use the exact same charging pigtail, BTW. It's too short to route down to the grille, but I'm going to extend mine. I can use either maintainer with my Leaf now, but usually it's the Diehard, because it can top off faster. Anyway, once a week, connect the maintainer and top the battery completely up. Don't do it while plugged in and charging, though, as this appears to trick the maintainer into thinking the battery is full, because of the higher voltage (but apparently inadequate amperage) that is present in the circuit while charging.

 

[Nubo]

I am part of the group with a bad battery.

I took it to the dealer and they said the battery was fine even though I had a voltmeter on it. They blamed my Ham radio that is totally controlled by a relay controlled by the acc buss. It draws no power with the car off.

Three days later it was totally dead after breakfast. Customer care towed me to the same dealer. The tow truck driver stated I had a bad battery.

Well, they replaced the battery under warranty but claimed it would not last due to my ham radio. The mechanics grasp at any straw to shift blame.

Oh yes. They love seeing aftermarket gizmos in the car. Instant blame target.

 

[Nubo]

It is astounding if this behavior hasn't been resolved in the 4th model year. :?

It's easy enough to avoid in most circumstances, but the customer shouldn't have to jump through hoops to accomodate a bad design decision.

 

[MikeD]

Could those who have had their batteries replaced identify the battery maker? Has that supplier changed, especially beginning with the Leafs made here?

 

[Stanton]

Could those who have had their batteries replaced identify the battery maker? Has that supplier changed, especially beginning with the Leafs made here?

Replaced my (stock) lead acid 12v battery with a LiFePO4 "drop in" 12v battery last year and have had NO problems whatsoever (which includes sitting in the airport in all kinds of temps and using a lot of accessories). Follow the link to my blog post for everything you need to know:

http://stanton.myevblog.com/2012/01/16/getting-the-lead-out/" onclick="window.open(this.href);return false;

 

[dhanson865]

It is astounding if this behavior hasn't been resolved in the 4th model year. :?

It's easy enough to avoid in most circumstances, but the customer shouldn't have to jump through hoops to accommodate a bad design decision.

Is it that simple?

Toyota hasn't made it impossible to drain the battery on a Prius and they've had 15 years to work on it. The common refrain is the battery is in the cabin so they want to avoid overcharging the battery and releasing gas into the cabin.

Tesla is hitting the same issue as well (less years under their belt) even though their 12v battery is in the frunk instead of the rear of the vehicle. I expect their engineers are working on this with a higher priority than their competition but I don't expect they've beat this issue yet.

Apparently if you don't have a gas engine running needlessly most of the time it takes a lot more effort to manage the 12v battery properly. It seems like Nissan/Toyota/Tesla all are of the mindset that replacing the battery every time you drain it too low is the way to go.

I really wish they would add a number to the dash or MFD during startup before the main battery comes online to show the 12v battery voltage. It wouldn't stay long unless they buffered the number to display to the user but I think it'd be nice not to have to go to extra effort to monitor the 12v battery on a regular basis.

edit: I have to remind myself :

But I think the larger 12V issue for LEAF is the way it perversely uses more power AND refuses to keep the battery topped off when the car is plugged-in to a power source! Depending on customer habits, this can introduce deep cycling of the 12V. Conventional automotive 12V batteries don't tolerate this well

oh yeah, Nissan Leaf is a little different than Prius in this sense, I think I'm going to have to agree with you that the Leaf has the worst use case of the 3. At least I already have a smart battery charger no matter which PHEV/BEV I buy next.

 

[LeftieBiker]

I really wish they would add a number to the dash or MFD during startup before the main battery comes online to show the 12v battery voltage. It wouldn't stay long unless they buffered the number to display to the user but I think it'd be nice not to have to go to extra effort to monitor the 12v battery on a regular basis.

I'm probably going to pick up a Chinese accessory plug voltage gauge from Ebay. The reading probably won't be accurate, but it should be consistent, so after calibrating it, I should know where the accessory battery is at with the car On, at least.