We have both, but everyone grabs the B/O ( B&D 18 volt ) trimmers first. Light weight, easy to use, cut well, store well. We have a gas too, used for long flat top runs, but per fer B/O for ladder work. Yes, we have many extra batteries, same used in all our cordless tools.
4-33" Sutech W/B's
2-stroke Com-Lawnboy 21"s