I searched Kijiji and found some for $50. or less, cordless mowers for sale, some good some with bad batteries.
From what I've seen if you don't keep the batteries charged or hooked to the charger as the manufacturer says they don't last.
Here's a short video of a 24volt, 17amp/hr, 20"cut, Yardworks cordless mower cutting some grass. Estimated run time 45minutes.