Check the voltage with the charger on and after the battery is fully charged or only when you first put the charger on? What should the voltages be in the 3 different scenarios you mentioned?

 

I suspect the charger got confused by the sudden draw on the battery and went into bulk charge mode. Opening the door wakes the computers and turns on exterior lighting. If you would have left it the charger connected, it probably would have reported fully charged in short order after shutting the doors and waiting a little bit.

I use a batteryminder which are highly regarded in the aviation industry. This charger has an indicator labeled "load" for this specific case. These chargers are not as easily confused. If you got money to burn, google 128CEC2

 

One more thought... If you have in your mind that the vehicle battery charger will count down in a linear fashion like a cell phone battery percentage read out, drop that thought as none of these chargers will do that. They can't measure the draw across the battery under load. They just move between their charging modes: bulk, absorption, float. When there is a draw, voltage can drop causing the charger to go into bulk mode. But if that draw quickly stops, a healthy battery will regain its nominal voltage and the charger will then shift back to float.
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It is not easy to know how your Charger program is designed to work and respond.
From your description, nothing is a-miss but a bit overdoing the charging and your expectations for the results.
When the door was opened, the system came out of the sleep mode, current drain got higher along with any lighting that added more drain.
This drain can get into a number of Amperes.
As well, the battery takes on a what is called a surface charge that can test as a higher voltage and drains off quickly to a lower more stable level that drains slower.
In many Manuals, it tells you to put a load on the Battery with the Headlights and or other loads for a couple minutes to drain off the surface charge to the Reserve Capacity level that is more represenitive of the actual Battery state of charge before an accurate an Voltage reading is observed.
It's at this point the Charger gets fooled, reacts and you see it when still connected..
If you watch what the Charger does it will fool you by the reaction because you don't know how it will react but to some expectation that may not be correct..
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it's all normal reaction of any lead acid Battery type.
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There is a concern that putting the charger on for long time intervals can cause Cell Sulfation. An internal cell chemical activity by forced charging at too high a level to long and depends on the charger's design operation..
If the charger has the ability to detect this condition, it can go into a high voltage charge, usually about 15.2 volts trying to recover from the condition, until satisfied.
The vehicle BMS has the same ability.
This is a lot to try understanding but is why there is often confusion with expectation and result.
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Lastly, the BMS program should be Re-set so it detects a new Battery as [new] and does not treat it as the old one was, for charging as it aged..
After charging and some drive cycles, the BMS program will take over charge control from the detected parameters at the Battery Sensor located on the Battery Negative post but the old data is still in program if not cleared by a specific Re-set action [other than] just a power down and up.
Disconnecting the Battery does not do >this specific re-set.
Good luck.

 

The image below from Pg8 in NOCO manual

 

I just got this charger. Seems to work great. I use it on my Charger though not the F-150.


I also got the below tester for the F-150 because I thought the battery was failing. After testing, it showed the battery is fine.

 

I agree with this. I bought a Noco Genius v1 and a v2 a few weeks ago. One for my mower during off-season and the other for my wife's car while she was out of town for a few weeks. The v2 did not perform as I expected. I suspect it could have been because I left the hood open so maybe the vehicle didn't full go to sleep and drew power faster than the 2A charger could supply. Although my gut says that's probably not it. Ended up just tossing it onto the shelf and drove the car for an hour to recharge it. The v1 appears to be working properly on the mower, but I haven't verified the voltage yet. Wish I had just spent more and got a 15A charger instead.

 

Yep...when it is in the Maintenance mode, it is doing nothing except waiting for the voltage to drop to a certain level and then it goes back into bulk.

 

Here is an article about the Victron IP65. After reading it and buying it...then around 5 other people I recommended buying it and loving it...it would be the charger I still recommend.

Victron specializes in off grid battery and solar components. They are the "go to" brand in that area.

https://marinehowto.com/choose-your-...ers-carefully/

 

Would this also cause it to read that the battery is under 25% and charging right when I put the charger back on after driving (even though I just drove 1 hour and 45 mins which should have been more than enough time for the alternator to fully charge the battery)?
Thanks for the detailed explanation. So what you're saying is that what I experienced may just be the charger reading the state of the drained 'surface charge'. If this was the case then that would also explain why the charger said that the battery went from under 25% to 50% in an hour (which seemed really fast for a 2amp charger).
What size charger is this manual image from? My manual shows different.
Thanks for the recommendations.
What size was the Noco Genius that didn't work?
Interesting but this still wouldn't explain the battery being at under 25% after being on the charger I don't think.
Thanks for the feedback. I almost bought this originally when it was recommended but I got cheap