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Hi. My 2012 Nissan Leaf 12-volt battery started to drain over-night roughly 2 weeks ago. I bought a brand new 12-volt battery and in 2 days it drained again. Can someone please tell me if they're having this problem with their car ? I have also tried turning off my car-wings updating system in the car and I also bought a larger battery and the same thing happened after a few days.

I await your response,
urgently.

Thanks,
Craig.
 

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I'd buy a charger rather than keep buying new batteries IIWY. Are you sure there's not a light left on somewhere?
 

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2020 BMW i3S 120Ah BEV
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If this were 1995 I'd sit there with an ammeter connected and pull fuses until I found the culprit... The usual suspects are doors/boot/bonnet not properly closed, or car alarm over-active because a window is down, or the ECU staying active because there's a contactless key sitting inside the car, or even you've left a diags dongle plugged in..
 

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There must have been a dozen threads on this subject in here over the last six years. Although not where a new fully charged, and therefore not suspect battery has also drained in no time. As others have said, in this instance there seems to be some kind of unusual drain that needs to be tracked down.

Previous experiences of low 12v voltage seem to be linked to a poor algorithm that is supposed to top-up the 12v DC battery from the traction battery - but often fails. But this a long way from a simple top-up so has to be a drain somewhere.
 

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My 2019 Leaf 40 suffered the same problem last week - used it Sunday fine, Wednesday went to open boot, would not unlock, the doors were open so lifted bonnet and checked battery - down to 4.5 V. Called Nissan rescue, RAC came out very quickly - within an hour. RAC man plugged in his battery boost and iPad, car started fine And 12V was charging correctly from the traction battery he said that it wont start if voltage is below 7V, he said that I needed a new 12 V battery but they aren’t allowed to change in the Leaf. The electrical alarm (orange car with exclamation mark) was also lit. I would need to drive it to nearest Nissan agent - Wessex Gloucester. Took it there, they kept it 2 days no fault found, 12V battery fine apparently. They said I must have left the car switched on ??

Brought it home, battery voltage around 12V, have connected my AA smart charger recommended elsewhere on this forum and its been charging for about 5 hours now, will see where it gets!
 

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2019 Leaf 40
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I wonder if the flat battery is something to do with keyless entry? It's happened with a few models.

Bit worrying. I wake mine up with the app every so often in the hope that it triggers it to check the 12v and charge itself.

If the battery is going flat from properly charged in 3 or 4 days that's quite a drain.

I'd think it's worth getting one of those plug in volt meter thingies to check the voltage while the car is in drive to make sure the battery is being charged and it would also show if you'd accidentally left the car in as it would be lit up showing the battery voltage. The Leaf turns off the accessory socket when it's fully off off.
 

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It took 2 days to fully charge the battery with my AA charger, at least it got there in the end! I have bought one of those power pack thingies the RAC man had as I often work away (in normal times) and dont really want to risk being stranded.
 
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