Last spring I bought a Kobalt Gen4 40v Max Brushless 20-Inch Cordless Electric Battery-Powered Lawn Mower. It did not disappoint. I mowed the entire, spring, summer, and fall on my 1-acre yard with the mower. Only thick, wet grass posed a problem - and it would have done so with a gas-powered mower as well. So now I'm starting season two, and the batteries seem to have held up well over the winter. I left them on the charger for nearly 4 months. Here's a look at how things faired on my first mowing session.