It seems like adding more battery to a Leaf could make sense financially. Even if you put this on a trailer, $300 for the trailer, another $100 for the plywood, around $3,000 to $4,000 in Jehu Garcia approved 18650's for another 24-30kWh. $1,200 for a separate BMS and at least another $1,000 for cables, bus bars, connectors, contactors and Arduinos. So at around $6,600 you could have some what close to double the range, as long as you don't burn anything down or get electrocuted in the process.
That beats owning a second vehicle. Well, the total cost of ownership of an average, cheap, used vehicle for 5 years is between $25,000 and $35,000 in the USA. Edmunds TCO calculator guesstimated that my Leaf would cost me $21,000 total cost of ownership for 5 years. Adding a $6,600 battery trailer to a used Leaf wouldn't be as cheap as owning a Ford Fiesta or Mazda2 as an only vehicle, but it would be close. And it would definitely be cheaper than owning a second car.
Of course the more sensible thing to do is patiently wait until Tesla 3's, Chevy Bolts and Gen 2 Leafs can be bought as cheap used cars.
2013 SL 50,000 miles.
12 bars until 44,300 miles on June 2, 2017.
11 bars current.
The Nissan Leaf is the fourth best long distance car for highway driving. >>Best Long Distance Cars<<