Engine: Kohler Command Pro 25 CV730S A week ago I had difficulty starting the engine. It finally started before the battery died. Yesterday, I decided to put a charger on the battery before attempting to start it. This is the first time I have used a charger on that battery. The charger was set for 2 amps and it was on for about 15 minutes. The mower started and ran fine. I mulched leaves for about 1.5 hours without incident. Today I needed to finish mulching leaves so I started the engine without needing to charge it. I mulched leaves for about an hour and the mower died. When I tried to restart it, the engine would not turn over - like a low battery. I removed the battery and checked it with a voltmeter. It read 10.6v. I put it on the charger for about 40 minutes, put it back on the mower and mulched for about 30 minutes before the engine died again. I removed and charged the battery for about 20 minutes. It now read 12.6 v. This allowed me to get the mower started and I was able to get it to my shop. While the engine was running, I checked the battery with a voltmeter. It read 14.1v. The engine is on a 2004 dixie chopper. It does not have an electric clutch or other electrical accessories. Why does the battery voltage drop during use such that it will not start the mower? It seems that the charging system of the mower would keep it topped off especially since it appears to be working fine (puts out 14.1v). Is this a bad battery or do I have another problem?