Ditto to both the above posts. While there are car brands with more complex battery setups than the Nissan Leaf, these cars are equally well engineered as Toyota vehicles in general IMO. I've had my 2012 leaf a few years now and besides the obvious battery degradation its been perfected for my...
As @ginetto says, the Leaf BMS is unable to cope with aftermarket cells at all. It can't even safely work with aftermarket MMC cells let alone Lifepo4. A Canbridge won't help either.
As others have said, internal cell resistance is high, confirming aged cells. Looking like you could benefit from a visit to EVs Enhanced in Christchurch.
Can you elaborate on what phone app you are referring to please? Charging apps for public chargers use the mobile network. Home charger connectivity is different.
Eco mode reduces available acceleration power. I'm not aware of any changes to the HVAC but others can advise on that. You can switch between Eco and normal at any time. E-pedal changes the accelerator pedal into a one pedal mode where electric braking happens when you take your foot off. There...
Afaik the 2011-12 leaf has its charger in the back and it's limited to 3.3kwh. Only the later models with the charger in the stack in the engine bay can be upgraded by swapping to a 6.6kwh charger.
I read somewhere yesterday that CATL claims the price of lithium batteries has fallen 60% in the last 12 months. Even if they are exaggerating it suggests battery replacement costs won't be a big issue in 5 years time.
I'd extend the BMS wires by joining and soldering them and heat shrink sleeve them. Use similar gauge wire to the original. Where you run them in bundles you should heat shrink again. The voltage difference between cells alongside one another is small but the wires need to be very carefully...