Same exact scenario for me.So yesterday, I noticed my Explorer sounded different when starting...sort of like harder to start than normal as the temps got colder. Since I bought my SUV in May 2018, I was guessing the battery was nearing 36 months since manufacturing.
I decided I was changing the battery to be safe since the temps will continue downward to near 0 degrees this weekend.
The dealership put the battery and electrical system on a tester for about 45 minutes. Results, battery was failing at 35 months, but since I was within the 36 month bumper to bumper warranty.....new battery was free.
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