I have an outdoor job and use a power wheelchair, I think you can see there's a problem. ;) But I'm looking into buying a track-driven wheelchair that will take me almost anywhere I need to go.

As I'm looking at the specs, the usable range is listed as 10 miles. I've used power chairs for 20 years and when a manufacturer says 10 miles, that means 7 at the very best out in the wild. That won't cut it for me.

I've been looking everywhere for more information and came across this page from a while back but can't find anything more recent that has anywhere near this much information. This particular chair isn't for sale and I don't think the components are either.

http://www.wheelchairdriver.com/BM-MK3-lithium-battery-powerchair.htm

I'm not an engineer and have no idea how to even start asking the right questions. Anyone have ideas where to start?