Need guidance. Ford power problem?

Asking this again because I explained incorrectly on my first post. Thanks for any assistance. I have a 2004 Ford Escape and for a while the battery light on the dash has came on intermittently, but stays on the majority of the time. I haven't noticed any performance issues other than when I get on the interstate I can accelerate up to about 60 miles per hour with ease but after that it's very sluggish to increase speed. A couple of days ago it seemed to gradually lose power. It wouldn't let me accelerate past 40 miles per hour and eventually got to where I could barely go at all. I coasted down my road into my yard and tested a couple of things to find out that my windshield wipers went incredibly slow and my accessories seemed like they had low power. I checked and the battery connectors we're a little dirty so I sanded them and I put a voltmeter on the battery and it read 12.2. I then cranked it up and it got to 14.4 volts. On my previous post I listed that it got to 13.6, which is incorrect, and caused a misdiagnosis I believe. With it getting to 14.4 I'm assuming that the alternator is good. My battery light is still on but it seems to run ok now, with the exception of once where it did seem like it was a little sluggish to speed up but it was minimal. I took it to an auto parts store and they tested and said the battery and alternator were good and it had a good ground. I don't know why the light is staying on, almost constantly, and I don't really know where to start

Sometime the diode in the alternator goes bad and the electricity leaks back from the battery through the alternator and the battery eventually goes dead. The strange thing is that while the alternator is running, it makes enough electricity to compensate for this drain and the alternator appears to be working well. I would ask them to check the alternator a little more thoroughly.
Could be some other parasitic drain. Light stuck on under the hood or in the glove box or?

How many batteries have you put in the car. Figure with each battery lasting ABOUT 5 years and you can use your fingers to do the count.
The factory battery is 1, and that lasts 5 years.(that is 2009) You go out and buy a battery and there goes another 5 (at 2014). Now I'm going with 5 year average. It is year 2019(so 5th year or known as BATTERY TIME.
. If the batteries only lasted 4 years (so that would be 2008&2013) Another 4 years go by and it is 2017 BUT YOU KNOW IT IS 2019 so you are denying an obvious cause.

The idiot light is saying "Hey idiot behind the steering wheel, I'm telling you there's a problem… And yet you refuse to listen.
. The alternator may be putting out but the battery is not accepting a charge. AUTO parts stores do not do testing. They just sell parts. Go to an auto electric store or a place that only sells alternators/starter motors and batteries. They KNOW HOW to check it. Hell, even Wal-Mart know how. And they also sell batteries. For your boat.
FORD is at the "FIX Or Repair Daily" stage in life.otherwise it will be "Found On Road Dead"

37+yr mechanic

14.4 VDC is right on the money for output. But obviously the Fuse/Relay Box, which distributes the power, is not getting that if your Wipers are slow, the BATT light is on and you're having drivability problems. That means the wire from the Battery Positive is NOT connected well or not Grounded well to the Fuse/Relay Box. Check all the Grounds first, then look at the wires feeding power to the box. All connections need to be Clean and Tight. PS I assumed you measured the voltage from the Battery, if not check the wire from the Alternator to the Battery. A good Battery should read 12.4 or higher, and those tenths mean something.

Have the spark plugs ever been changed? On late model ECU controlled engines misfires can cause what you describe as can low fuel pressure. More troubleshooting is needed to find the problem. Also just because the alternator produces voltage does not mean it makes amperage. The battery should test 12.6 volts or more after sitting overnight. If it doesn't the plates are probably covered with sulfate and produce voltage but not amperage. The ignition system is voltage and amperage dependent as Ford uses an inductive discharge system that needs both to operate correctly which should also be checked for voltage leaks and output.

You will really need a wiring diagram for the charging system of your car to diagnose the issue. The wire from the battery warning light at the dash to the alternator could be shorted to ground so the battery light will always be on even though the alternator checks ok. Pull the connector at the alternator and find out the which one is the "L" terminal. With key ON engine OFF, battery light should be OFF. If it is ON, the wire from the "L" terminal is shorted to ground. Confirm with a test light connected to battery negative. Touch the L terminal with the test light (with key ON ). If test light does not light up, the wire is shorted to ground.

You can also check the voltage at the "L" terminal when it is connected to the alternator with the engine running. Get a T-pin and connect it to the L terminal (at the connector). With engine running, touch the T-pin with a test light connected to battery negative. Test light should light up. If the test light does not light up, the alternator is bad.

For the low power issue, check the voltage at the headlight connectors (with the switch on) with engine off and engine running. Voltages should be the same as the voltages across the battery. If voltage are not the same, check for a voltage drop at the cable from battery positive to the fuse box.

And voltage and amps are not the same. The alternator should be checked with a carbon pile tester. The alternator might put out the correct voltage but might fall on its face when under load. CONFIRM if the alternator was tested with a carbon pile tester. This could be problem with the low power issue. If nothing else, just replace the alternator if the alternator on the vehicle is the alternator when the vehicle came out of the factory.

The guys at the parts store aren't mechanics, though they can usually put a meter on it and tell you what that shows. It isn't enough, though, for the problem which you appear to be having. You need a competent auto electrician who can go through your entire system to pin down the fault.