I have 4 versions.
The control. Just plug it in. Did that last summer, saw 8 bars a few times, didn't have leaf spy.
Version 0, almost as simple as the control. Easy stuff any one can do, open the hood, charging at night, avoiding full charges.
Version 1 is simply remove the battery cover, but leave the fuse cover in place and stick a duct in the window through a scrap 2 inch thick construction foam window shaped cut out. This will definitely cool the car off some, maybe the battery too. A little of both would be ideal.
Version 1.1 now the ducting is longer and goes all the way up to the battery cover on the floor.
Almost all of the cool air ends up on the battery case.
Version 2, the secret weapon. insulated and climate controlled garage. All the insulation is bought, half of its installed, The coal furnace is in the garage and heats like summoning a portal to hell. It will help keep the garage warm in winter and I have a 2 ton split heat pump that I'm not using right now, was going to put it in my new rental but I think I would rather it be in my garage.
Only plan on getting the garage insulated by winter, the heatpump going for next summer.
Version 3. Crack open the battery repack the cells, add some heater pads, punch some holes in the battery for ducted forced air cooling, spray foam and asphalt coat the battery case. Probably summer 2021.
By 2021 I doubt I will be the first to do something like this.
2011 white SL leaf with 2014 batt.
Chargers: Panasonic brick moded for 240v, duosida 16a 240v and a 10kw setec portable CHAdeMO