baustin said:
If only the battery pack was taken from the 2014 Leaf, you just need to install the replacement battery pack and get a dealer to pair it. This will require a Leaf Authorized dealer.
If you have access to the previous owner and battery pack, you just need to swap the BMS board between the packs. You should then be able to install the 2013 pack in the 2014 and be up and running, with no dealer involvement.
The key fobs need paired to the car, and all key fobs that are going to be used with the car need to be in the car when the pairing is done. This usually requires a Nissan dealer with a Consult tool.
I actually talked to Cor about this a few days ago. I believe you should be able to simply install the 2013 battery into the 2014 leaf. You might find the that battery cover panels will not fit, as they have changed. I would try to use the cover panels from your 2013, but if they don't fit, you'll either have to leave them off or get some on LKQ. The actual electrical connector changed between 2012 and 2013, but 2013 & 2014 should have the same connector, so you should be good there.
First ensure that the battery disconnect is removed from the pack and use electrically isolating gloves when insulating the various contacts on the battery pack. Keep in mind that the battery disconnect splits the pack into two halves. This means that the contacts still have ~200V (instead of the 400V). 200V DC is still lethal. Also, the pack is ~800 pounds, so you'll need the appropriate jacks and stands. Do use stands--hydraulic jacks can fail at any time and without warning.
Once you get the battery pack installed and connected, you'll need to replace the disconnect in the floor between the rear seats, which should energize the car. At this point, the car should work, but provide a turtle icon and motor power is limited. I believe you won't need to re-pair the keys if you have the original keys from the 2014 Leaf because you're not changing the VMS computer.
You'll need to drive (<25 mph) or tow the car to your local Nissan dealer and pay them to use the consult tool to re-pair the battery to the car. You should be good to go at that point. Be sure to call the Nissan dealer first to ensure they're willing to do the work and you know what paperwork you need (title, etc) to do the work.
If you live in New Zealand, you could call up http://evsenhanced.com/ and see if they'll do the work for you.
Anyone more knowledgeable feel free to chime in. I haven't done this specific repair, so I could be wrong on some of the details.