Anyone know if electric lawnmowers are any good?
Or generally what to look for?

I don't have much yard or shed space so just want something minimal effort/grease/maintenance

@arichtman I used to have a fairly cheap cordless mower when I used to mow my own grass.
It was great; being cheap the battery didn't last that long, but enough to mow half a decent sized suburban block in the morning, charge it through the heat of the day, and finish the job in the late afternoon. No doubt a better quality one would last longer. But even that cheapy would chew through thick grass and stalks better than any petrol mower I've used.