I’ve got around 400 sq metres and I have used a Bosch 36v for more years than I can remember. I do have 2 batteries though.
The length of the grass will make a big difference, let it get too long and you can drain the batteries very quickly. However, keep it under control and 2 batteries will do my patch.
I have upgraded though to Ego 56v mower just last year. A variety of batteries are available from I think 2ah to 7ah. I went 5ah and again this is more than enough for my lawn. The reason that I upgraded was Ego also do a load of other garden stuff as well, strimmers, chain saw etc.
And just one more thing. The Ego is a bit heavier than the Bosch, but my wife can lift the Bosch, if you get my drift :wink:
I’ve just purchased a sthil cordless mower, only because I’ve already got the batteries, I’ve used it twice so far and can highly recommend it, our lawn is only tiny (60m2) and my wife couldn’t start the petrol one. She’s very happy using this one.
As has already been said length of grass can be a issue, cut your lawn weekly and you won’t have any problems with a cordless mower