It's that pesky 12V battery yet again...

[PeteTranter'sSister]

You may recall that I have had problems with setting my Ariya to charge overnight, with the 12V battery discharging completely on five occasions now, leaving the car as dead as a dodo. Shortly before it goes completely dead it does a mad software dance, sometimes with the alarm on, necessitating me forcing the boot (trunk) open so I can get to the 12V battery to uncouple it and recharge the traditional way. On a few occasions I have managed to get to it before it completely died, including today, so it recharges using the traction battery. Nissan didn't find the fault but replaced the 12V battery at the 12 month service in December but it's done it twice since then.

So I bought a 12V battery monitor, set the car to charge at shortly before 11am this morning for a cheap rate charge at 12.30 am tomorrow, and watched in anticipation:

As you can see, whilst waiting to charge for 12.30 am tomorrow morning, the 12V battery gradually dies, despite recharging cycles, and I managed to intervene and save it at around 4pm. It manages about 5 hours waiting before it gives up. Which is why it hasn't been doing it lately since I have the sense to set it to overnight charge last thing at night.

It's in for a 2-day observation on 30th May, let's hope they can identify why it's discharging whilst waiting to charge. Then there's the lumbar support, random alternation between km/h and m/h, broken heated seat, random software warnings, steering wheel change etc. Love the car but the, er, 'software personality' is driving me bonkers.

PTS

[Milkfloat]

Whilst Nissan are at it, could they possibly explain why the 12v battery is run at such low voltage? So far, so good with mine but why the heck is it operating either side of 12v. It has less than half its capacity at that level.

[karltk1]

Mine has died 4 times now. This battery is only 5 months old. Did weird stuff whilst washing the car, alarm going of mainly, then died. I keep a booster pack in the rear of the car, so I can always get the bonnet open to wake the BMS up. Then it will start charging from the traction battery. Why is the BMS allowing the 12v battery to get so low it fails. 11.72 volts this time. Even if something is draining the 12v battery, the BMS should force charge until the traction battery gets to a safe limit, surely. It should never get that low. Most of my faults are charging issues and intelligent power management issues. Had a few sensors come and go to. I get sensory faults frequently enough, especially when it rains. Forgetting seat memory settings, not auto locking. Just want it to work reliably.

[PeteTranter'sSister]

After life saving the 12V battery late yesterday afternoon, I set the car on the timer to charge overnight, leaving it at late as possible just before I went to bed.

It did the weird 12V battery dieing death dive thing but didn't die before the timer kicked in at 12.30am, at which point both the traction battery and 12V battery charged until the timer cut out time of 4.30 am. The 12V battery is now sitting quite healthy at 12.7V. However, the repeat charge timer has stopped so if I leave it, it won't charge again tonight. No green flashing light on the dash, even though the dash says 'charge timer on', and no green flashing home charger.

So setting the overnight charger on a timer puts the 12V battery into a death dive, unless the charge timer cuts in before it completely dies. If it does manage to get to the 12.30 am timer then both the traction and 12V battery get recharged, but the repeat timer function fails, which is probably a good thing since if it didn't it would be waiting to recharge from 4.30 am and presumably going into the 12V battery death dive again and dieing by around 9.30 am.

I shall be taking this evidence to Nissan for the 2-day observation on 30th May, when they will also be changing my steering wheel and fixing the heated seat element. I am thinking of holding a raffle for their response:

a) We can't find a fault
b) It's your home charger. (Even if it is then it still needs investigating).
c) We've pointlessly changed the 12V battery again.
d) We can't find a fault
e) Because you fitted a 12V battery monitor, it's now out of warranty.
f) We can't find a fault
g) We've found the fault and it's all sorted. Nissan have worked tirelessly to sort out all the software bugs and a new update sorting absolutely everything out is now available.

On another matter, I've also discovered a trigger for the random lumbar support inflating. If you start the software, then stop the software, then start the software again (for whatever reason), then I find that the lumbar support inflates every time. Not a life changing fault but just another annoying software glitch.

Karltk1, you should get a 12V battery monitor from Ebay. Cheap, dead easy to install, great app, and at least I now know wtf is going on with the 12V battery.

I shall let you know Nissan's response in early June,

PTS

[karltk1]

My car is in for a week to test and fault find. Or not test much at all. I gave them a common fault list from my code reader, most is the intelligent braking system, a few charge issues and a few of a number I can't find anything for. So will see what happens. When it gets very wet, it seems to suffer more. I will wait for your assessment until I get a battery monitor.

I last tried one but the software kept flagging up error message on my anti virus software. So didn't use it.

May give it another go. Now I have a nissan leaf for a few days. Single pedal driving. Can't believe they got rid of it for the Aryia. It all seems to work to.

[gustavwest]

The firmware seems to monitor the charge port, whilst waiting to charge on the timer. This gradually runs the 12 battery down to the pont where it can't even power the onboard computer.

The solution I found is to press the button inside the door to start changing immediately, about 30 mins before trying to start the car. This will also start changing the 12 battery and give it enough boost so that the car will actually start! After this, as long as you go on a reasonably long drive, you will be ok, until the next times charge

The Aryia is a lovely car, but the firmware is absolutely riddled with bugs! More bugs than an ants nest

[gustavwest]

Further to my previous post, if my "solution" still results in errors when trying to start the car, you'll probably need to unplug the charging cable, then lock the car and leave it for about 30 mins.

The onboard computer then appears to go into deep sleep mode, which is equivalent to a reboot. Hopefully, when you try and start the car a little later it will be fine, as long as the 12 volt battery held it's charge

In my opinion this is a critical problem that Nissan must fix!

If all their future EVs exhibit similar behaviour to this 12 volt battery issue, it could bring the company to it's knees!

I for one and I should imagine noone else wants to prat about for over an hour, just trying to get their car to start because it's 12 volt battery charging firmware hasn't been properly Pre Production tested!

Tut tut Nissan!

[Cosmyc]

I wonder if this could this be an issue of only RHD UK Ariya's? I have seen in the service manual that the strategy charging time is different for those compared to LHD European ones.

[karltk1]

My issues seem to be caused by the Battery Control Module. In particular the doors not locking or unlocking correctly. Plus a myriad of other electrical gremlins. Not sure if it will cure the 12v battery drain, but they are replacing it. 3 to 6 weeks though on back order. ?

[Cosmyc]

Oh now I see, if the Auto ACC function (accesory position on a manual key car equivalent) is being invoked frequently due to, for example, erratic door sensor that tells the car someone is opening and closing doors constantly, that will fry the 12V battery for sure, and if that happens in a few hours then the DC-DC converter will not keep up the battery alive with the daily top up feature.