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2018 Ford F-150 — battery dies after the car sits for a weekend

UsedCarTuner681Community StarterFeb 17, 20262018 Ford F-150 XLT 2.7 EcoBoostCleveland
2018 Ford F-150 XLT 2.7 EcoBoost, about 116,500 miles. Battery passes a quick test and charging voltage looks normal, but after two or three days parked the car sometimes will not crank. What is the cleanest parasitic-draw test on a modern car that takes time to go to sleep?
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4 replies

ApexEnthusiastCommunity StarterCommunity StarterFeb 18, 2026permalink
Before you spend money, on the 2018 Ford F-150, I would treat a 12V warning as a no-ignore even if the pack is full.
RustBeltLearnerCommunity StarterCommunity StarterFeb 18, 2026permalink
If it were mine, compare a couple of chargers before blaming the 2018 Ford F-150 — site sharing and pack temp change the curve a lot.
ApexEnthusiastCommunity StarterCommunity StarterFeb 18, 2026permalink
I would start here: starting SOC and battery temp need to match if you are comparing charge sessions.
SunBeltDadCommunity StarterCommunity StarterFeb 19, 2026permalink
Fair, but I would not clear alerts before service can see them on the 2018 Ford F-150.
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