It is supposed to charge 4 min out of every 24 hrs when it sits. I have witnessed this function happen. Whether that is enough to keep it charged, will depend. Esp if there is something left on (OBD dongle, light etc), as with any car it is possible to drain the battery in all the ways mentioned. The RAG (roadside assistance guide) from Nissan says to pull the HV disconnect between the seats, and after waiting 10 min disconnect the neg 12 volt lead when the vehicle is stored. Any vehicle I have that doesn't get driven in a month (or expected to not be driven) gets the battery disconnected. The risk of a critter damage on the wiring and possible fire from same. I have a few antiques that sit over the winter. I also have a 3 season road car that I don't drive in the winter, it has the same battery that the Leaf uses (gp 51R) and will deplete the 12 volt if left sitting all winter also.
4 min charge every 24 should do better than mine which has a ICE engine and will not do anything, although it is much older (40 years old) so has less key off loads than a modern car. Any car made in the last decade or so has more gadgets that draw a little power all the time and wouldn't fare much better if at all.
To sum up, I'd say if you plan on long term storage to follow the advice from Nissan in the RAG guide, or put a maintainer on the 12 volt, that will prevent the HV battery from needing to try and charge while sitting, It would wake up, see the 12 volt doesn't need a charge, and then re set the 24 hr timer. It will not save you from critter damage, but would allow but would prevent what you had happen.
Having said all that, many have reported going more than 2 months and not having a problem. If since you did, I would be looking for a draw and not just saying the 12 volt is defective.
4 min charge every 24 should do better than mine which has a ICE engine and will not do anything, although it is much older (40 years old) so has less key off loads than a modern car. Any car made in the last decade or so has more gadgets that draw a little power all the time and wouldn't fare much better if at all.
To sum up, I'd say if you plan on long term storage to follow the advice from Nissan in the RAG guide, or put a maintainer on the 12 volt, that will prevent the HV battery from needing to try and charge while sitting, It would wake up, see the 12 volt doesn't need a charge, and then re set the 24 hr timer. It will not save you from critter damage, but would allow but would prevent what you had happen.
Having said all that, many have reported going more than 2 months and not having a problem. If since you did, I would be looking for a draw and not just saying the 12 volt is defective.
