Computerizer wrote:I jumped it with the 2012 and it's now sitting in the garage in "READY to drive" for at least 20 minutes, as the manual states in the jumping instructions, to charge the 12V battery back up.
It is not possible to fully recharge a 12V lead-acid battery in 20 minutes. (At least not the kind in the LEAF using the charging system in the LEAF.). Unfortunately, the way the LEAF charging system works, it may NEVER get fully recharged, no matter how long you leave it in READY mode.
Computerizer wrote:Any idea what could have caused the 12V battery to die in less than 24 hours? There were no lights on in the car or anything, it was just sitting there.
It could just be a bad battery. I would definitely try to get Nissan to replace it. I would not drive the LEAF with a bad 12V battery given some of the reports of strange things that can happen in that case.
But it could also be an issue with the car itself. The most obvious issue is that the charging system in the LEAF is not good at fully recharging the 12V battery. But there are other possibilities. One 2013 came from the dealership with a loose battery terminal. I recommend you check that. Finally, there could be a problem with the DC-DC converter that charges the 12V battery. That is highly unlikely, given that we have no reports of a failure of that part of the LEAF.
If you have a battery maintainer, I recommend using that to fully charge the LEAF battery, as several of us have decided to do given the poor charging characteristics of the LEAF. If you don't have one, you may be able to borrow it from a neighbor.