There are several possibilities, including but not limited to:
a) crappy batteries
b) insufficient charging system (undercharging)
d) parasitic drain
e) driving pattern/habit that leads to a not fully charged battery
All 4 batteries being crappy is highly unlikely.
I don't know anything about the Escape's charging system, but the 90A (factory) alternator in my '95 Bronco was slightly undersized and when it failed I replaced it with a 130A alternator.
A simple voltage or current drain test should be able to test for c) and d). Methinks overcharging is very unlikely.--
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