Thanks guys for interesting facts. Seems 30kwh effort doesn't worth it: more expensive and heavier battery, adapter to connect it to gen1 + pair tool, both for "who-knows-what" money that's not even announced by this NZ company, plus higher chances to get same problem that I have now rather sooner than later. And only for 6kwh - low ROI I'd say.
Thanks a bunch, queried them.
To be fair, the tool is individually and hand made by the company (quite well, too), so they're targeted to shops that repair cars (not individuals). The price is known, but not published on the website. The best plan for an individual is to rent the tool, as it would be very expensive to buy for just a single swap. The engineer at the company is very professional, helpful, and has done numerous presentations to help EV's and the EV market. He provides rather rare service for Leafs in New Zealand, which is important, as the only support and supply for those Leafs is imports.
I know all of this because I've used the tool to swap batteries between two cars. It worked exceptionally well with no issues. I don't own the tool--I rented one from a "local" shop that has them. In short: The company is real, is doing a significant service to EVs and in particular Leaf owners, and the tool is not "upcoming" or vaporware.
That said, you can't use this tool to pair a 30 or 40kWh pack--unless you already have a 30 or 40kWh car. The tool only supports pairing like for like batteries. At some point in the future, someone may provide a solution to install a 30 or 40 kWh battery into a 24 kWh car and have it work properly, but that does not currently exist. Nissan has engineered the batteries to be incompatible, even though it would be rather easy to make them compatible. The connectors, mounting brackets, and physical external of the pack are identical. People have mounted 30 or 40 kWh cells into a 24 kWh battery pack, using the 24 kWh BMS. And the range estimation and charging circuitry don't work right (due to different voltage curves), but otherwise everything functions. So, if Nissan really wanted to provide 40 kWh replacements for 24 kWh cars, it would be trivial to do so.
In any case, if you're looking to do this, you need to search for either 48 24kWh individual battery modules (96 total cells), open up your pack, and swap the cells, or you need to do a full pack swap with a 24 kWh pack. The best pack to use would be a 2015 pack with 12 bars, but realistically, any 11 or 12 bar pack from 4/2013 or later would be a good choice. Keep in mind that the packs are 600-800 pounds each, so installing them is no trivial matter. You need heavy duty tools, preferably lift tables.
Opening up the pack is even more dangerous--you have to disassemble 48 modules in a pack that, even with the safety fuse pulled, has > 200V running through the busbars. You need the necessary HV safety gloves and insulated tools for such a job. This is why the NZ tool was developed--when doing a pack swap, you can pull the safety fuse, which eliminates any external electrocution hazard when doing the pack swap.
Hope this helps.