- There has been a lot of comments on this board about battery life; and as someone who doesn't have all the knowledge that many of you do, I thought I would share my experiences. I have been buying from www.batteriesasap.com or just recently, www.batterymart.com. In most cases, I now get the universal 12v 22h battery. The first summer, I usually get 4-5 hours out of them and the second summer about 3-31/2. After two years then I'm down to 1-2 hours. I charge them in the robo mowers or with the rapid charger and these mowers are cutting about 5 hours a day two- three times a week in the spring and twice in the summer. I have a half acre so they get a work out. Thought I would just past this along.