I bought a new Optima D34 battery June 2009 for a starting battery. I have maintenance charged it periodically over the last 9 months. Checked it this week found it about 50% charged. Put the charger on and after charging overnight, checked it it was 100%. I checked it two days later and it was 30-40%. I took it back to Sam's where I bought it and exchanged it for a SC34M Marine Starting battery, which had more MCA and CCA but less Res min. Just wondering if I made the right selection. I run a lot of electronics as well as an aereator pump. Anybody tried the SC34M?