What about AC? When I was in the planning phase to make one I noticed some speed controllers offered an "idle" feature. This means the electric motor would spin at a thousand rpms and you can use it to turn a pulley and an ac compressor and you would clutch the car like you would if it had the gas engine in it.
Another idea was to use an electric compressor like from a HCH or prius or worse to worse use a second electric motor with controller just to run a compressor.
I drove a Leaf 40 miles and cant say I saw any change in consumption with ac on or off as the electric motor seem to draw a lot in relation.
Also have you tried limiting the amp output to further increase range? For example set the max amps to 500 so you can still accelerate safely, yet estimate your absolute range based on a max 500 amp draw?
