Sounds pretty obvious right? Turns out the OEM BATTERY may have been an AGM cell design not the conventional flooded cell design. I know from a recent experience when replacing this Costco Interstate replacements the battery life of each one was closer to 1/3 the warranty. I noticed the negative cable contained a loop coupling sensor which I presumed is a current sense likely for ECM control. Since AGM batteries cannot be charged at constant voltage as with flooded batteries, I beginning to wonder if these Costco Interstate replacements are flooded cells as opposed to the original AFM battery originally equipped.

Possibly this is the reason why battery life in this car has consistently been short. This is why I need to determine the type battery design originally equipped for this vehicle. Then I can determine if the Costco recommended battery is indeed correct given they only seem to size batteries based on cold cranking AMPS.

Thanks indeed!

 

What amount of time is "consistently short"? Which battery you need depends on what engine you have. The 2.4L came with a group 47 (same as H5) battery with 525 CCA. The 3.6L came with a group 48 (same as H6) battery with 660 CCA.

​​​​​​​The loop coupling sensor you saw is an ammeter the ECM uses to monitor the current draw of the vehicle. Whether or not you use an AGM battery shouldn't affect the overall life much, but generally AGM batteries do fare better in automotive use. This is why they are commonly used in vehicles with engine stop/start systems that automatically kill the engine and restart it during traffic stops.