Speaking of battery electric yard tools: a few years ago (probably approaching 10 years, now) I bought a Makita 36 volt chainsaw. This was when they were using a single, big, 36 volt battery rather than two 18 volt batteries. My housemate wasn't happy because she didn't think we needed a cordless chainsaw to go with the corded one we've had for many years, but I was concerned about storm damage in the form of fallen limbs. Anyway, not long after we bought it, we had a big storm, and our main sidewalk was filled with fallen limbs - BIG ones. The saw paid for itself that day. It then did so again a few months later. I've used it to clear storm damage, often with concurrent power outages, several times. It hadn't been used for a couple of years, so I got it out to make sure it was ready for a storm. I store it with an 80% charge - Makita was smart in having their chargers show when 80% is reached, even if you can't select that as a stopping point. Nearly any cordless power tool with a lithium battery would have a dead battery by now, but the saw battery had about a 60% charge. I removed and charged to battery to 80% again, cleaned it up, adjusted the chain tension (it uses a nifty, easy to use tool-less adjuster), filled the automatic oiler reservoir with vegetable-based chain oil, tested it, and now the saw is ready to pay for itself for about the fourth time.