I've been using the hell out of this Greenworks 40 volt unit for the past 15 months.
Greenworks 40 Volt Pole SawAfter renting a Stihl gas-powered unit (which beat me up after a full day of use), I was very skeptical about whether a battery-operated chain saw could do the job. I'm a skeptic no more. I'm sold.
This thing has been absolutely great cleaning up along fence lines on some properties I own, as well as pruning oak trees around my home.
Out of the box it's just under 9' long. But, I bought a couple of 2-1/2' extender poles and it reaches way up to just about anything I need to cut. This model actually has the sections screw together, rather than having a couple of telescoping sections.
Technically, Greenworks says only to use one extender pole, but after reading an Amazon review where the guy had used two with no problem, I gave it a try and it works just fine, as long as you have the strength not to let a 14' long tool get away from you.
It comes with a 2ah battery, which is plenty to drop a bunch of limbs. As you can imagine, it takes a whole lot more time and effort to cut up what you drop, than it does to drop them!
Oh, I've still got a manual 25' pole saw, but it doesn't get much use these days. Thank goodness.