Are you going to be running them in parallel? Essentially, if you run two batteries on the same circuit all of the time, you want them to be close to the same specifications. Because, if not, the batteries will end up trying to charge each other instead of using the power they are being to called to use (If that makes any sense). It is not really harmful to wire them in line, but it can put just as much stress on your alternator in the long run....
I am not positive about the kinetik batteries, I know the optimas are designed to replace starting batteries while being able to maintian the high cranking amps. I guess it would depend on what the CCA for the battery is...
What I have seen people do is get a three way switch that will allow the alternator charge batteries in different forms varying upon the situation.
"The second battery is charged using a continuous duty solenoid as the isolation device. With the three position switch mounted on the dash I can charge both batteries, isolate the auxiliary battery, or jump start myself. "
(Quote taken from
Adding an Auxiliary Battery )
