I own several "larger" ranch style weed eaters, pole saw, blowers, chain saws, etc so I spend some time in the local Stihl and Husky shops. From what I understand they are getting better, but you have to buy several battery packs. They have a whole harness setup to carry batteries on your person. I thought about going the battery way, but they talked me out of it.
I just pony up the big bucks for the factory pre-mixed gallons of fuel. I think it is about $17.99 per gallon, but you can let things sit for months with the factory ethanol free fuel without any problems.
If I know I am going to burn through a couple of gallons in a day with the chain saws, I will run pump gas then at the end of the day dump out any remaining gas from the saw, fill with expensive stuff, then make my final cuts.
I did buy a 20 gallon gravity feed gas caddy thing, but need to remember to take it with me next time I go to Fredricksburg, they have stations with ethanol free gas.