Originally Posted by Mike_Engle

The optima batteries like an even 12 volt charge, the JK charges at about 13.5 - 14.5 volts which kills the optimas. They last about a year or so before you have to replace them. Look for a deep cycle battery that can accept the charge the JK alternators put out. I use an Exide Orbital AGM Deep Cycle Marine Battery. They might cost a little more then the optimas but they are far superior then then optimas.