Originally Posted by BobsWK2
You do know the WK2 does use an AGM type battery and these aren't available in many auto parts stores..
An AGM (Absorbent Glass Mat) Battery, also known as a VRLA (Valve Regulated Lead Acid) is not particularly unusual nor does it need to be replaced with an AGM design.
There are two advantages to an AGM (or VRLA) Battery and one rather significant disadvantage. On the plus side: 1.) It is more resistant to high frequency vibration damage (a failure known as Mossing) than a traditional Flooded Battery and 2.) Because it is completely sealed it can be turned on it's side or even completely upside down and it will not leak. As a result it can be shipped through the mail. But high frequency vibration is hardly a problem, even in a 4X4 passenger vehicle. Then unless you're going to drive your Jeep upside down (or at angles that will imediately result in this position) the sealed nature of an AGM Battery has little value as well. On the other hand an AGM battery is very sensitive to high charging rates. Hint! Take a look at the maximum recommended charging rate on an AGM battery, and then compare that to your Alternator rated output . . . that'll give you pause if nothing else . . . An AGM battery does not play well when subjected to the sort of charging rates that your charging system will deliver if the battery is run down, even when it is not discharged below 65% SOC (State of Charge) which is still a SOC sufficient to start the engine at temperatures as low as 0*F.