Focus 2013 key fob battery drains completely in ~1 week

[keksbg]

Ever since I bought this car it seems that the key fob drains completely. This car was previously part of a car crash, it was later fixed up and its modules were reprogrammed/recoded, and only after then did it start to drain in so little time. The previous owner said he didn't ever experience any issues like that. I've checked the car for any faults and there's nothing, all is clean. Manually checking each module also yielded no weird results/behavior. I've tried reprogramming the module but to no avail. I just have no clue anymore and I don't want to be left randomly stranded if I ever decide to go out and the battery drains on my *****. It's been doing this for over a month now and I'm completely clueless and I can't find anything other than the usual "check the key fob for issues", I've tried with a different key fob and that too has the same issue. I'm not cheaping out on the batteries, I'm using Duracell flat ones.
If anyone has any clue about this, please help. I'm starting to become a paranoid schizophrenic over this.

[StephenFord]

47 minutes ago, keksbg said:

... I'm using Duracell flat ones.
 

Aahhh, there's your issue, you should never install a flat battery, needs to be fully charged! 🤣

Welcome to the forum, and I'm sure someone sensible will be along soon...

[unofix]

5 hours ago, StephenFord said:

I'm sure someone sensible will be along soon

I wouldn't be so sure !!!

Does the car have keyless ignition and keyless door locking ?  If it does then you need to try a little experiment. Put a new battery in one keyfob and check it is working. Then take that key and move it well away from the car, I mean well away, give the key to a friend or leave it at work. Then after a couple of weeks try that key and see if still works. If it does the problem is the car. If it does not work then the problem is the key or the batteries you are using.

[mjt]

I was thinking along the same lines as Unofix. I may be wide of the mark here but this is my thinking: If the car has keyless ignition I think it interrogates the key periodically because I've noticed with mine that If I get out of the car I get a warning sound after a while. When the car interrogates the key it will respond with a short code transmission. I wonder if your car is constantly interrogating the key, causing it to be constantly transmitting a response. The experiment suggested by Unofix would give a steer on this possibility.

Hopefully @JW1982will be along shortly. He knows all there is to know about Fords.

[keksbg]

It does have keyless ignition and door locking, problem is the key is really far away from it 90% of the day. Our car is ~150m away from our house, so I doubt it'd be draining the key, we're close to it only when we're driving (actually not that much and not for long distances). Seems weird but I'll try the little experiment Unofix suggested.

[keksbg]

I'm gonna bump this, I still have no clue about anything.

[unofix]

and the result of the experiment was ????? If I'm not mistaken it seems a good bit less than two weeks.

[keksbg]

It's been less than a week and it still seems to hold charge. I'll wait out until the 1 week mark and see what happens.

[keksbg]

Alright, hi again, it hasn't discharged yet. Few days ago I checked if there were any faults registered on the car, but nothing. The other one keeps discharging though.