For mowing, unless you have an extremely small yard, you'll need multiple batteries. My property has 1/2 acre of grass. It takes 5 to 6 complete charges to mow it all. I have multiple batteries (all brand new) and split the job up over two days to allow for recharging time. Eventually I'll buy more batteries so I can do it all at once, but I'll need at least six.
Also, recharging takes longer than advertised when you factor in the time for the battery to cool down before the charger will charge it. Let it cool before you put it on the charger, because once the charger decides it's too hot, it simply will not start charging it until you take it off, let it cool and put it back. I put the batteries under a fan to cool them quicker. GW says they're introducing a fast charger this month, so hopefully that will speed things up.
Tip: When mowing, you might think you're saving battery life by stopping and restarting the motor, for example when moving from the front yard to the back. Don't. Leave it running. The drain during restart is a lot higher than when the motor is just idling. On mine, each time I restart the motor takes another bar off the battery indicator.
We just moved into a new home we had built and after previous experience with traditional gas lawn mowers I made the executive decision for the family to go battery powered. For multiple reason, of which I won't go into here. This 5.0 battery is AMAZING. My husband (and 13 year old son) can do both the front and backyard on 1 charge. I was extremely skeptical about that claim but it is legitimate. Our yard really isn't all that big (though it is decently sized) so I don't know how it would do on a bigger yard than ours, sorry I do not know square footage.
Was going to get spare battery for more and got inverter for that and to take camping. Use it to power pump to inflate kayaks, SUP's and power music. Might have given it 5 stars but have not tried it in colder weather yet!
The 60V 6.0 Ah HC Battery is the best! I have the 2.0, 4.0 (died) and now the 6.0 and the difference is fabulous! I live on 1/2 acre in No. Ca and I can blow off 4 decks, back and front yard, street in front of house, my rural mail box area and I still have power. I had to use both battery's before so my life is easier now. GET THIS BATTERY and you won't be disappointed.