Did I understand correctly that a low vehicle battery can affect the operation of the keyless door opening?  I've had some occasions recently where the door button doesn't unlock the car but the button on the fob will work.  Then later, the door button will work again.  I recently changed the fob batteries as a matter of course as we were going on holiday.

If the vehicle battery is low then I would have thought that I would have had trouble starting the car which I haven't had (so far).  I've got similar voltages to those mentioned by Bobr (12v static and 14.6v running).  Having said that, the battery is the original so it is now over 10 years old.  I have routine of trickle charging every now and then because of my short distance driving pattern.

8 minutes ago, Magenta said:

Did I understand correctly that a low vehicle battery can affect the operation of the keyless door opening?  I've had some occasions recently where the door button doesn't unlock the car but the button on the fob will work.  Then later, the door button will work again.  I recently changed the fob batteries as a matter of course as we were going on holiday.

If the vehicle battery is low then I would have thought that I would have had trouble starting the car which I haven't had (so far).  I've got similar voltages to those mentioned by Bobr (12v static and 14.6v running).  Having said that, the battery is the original so it is now over 10 years old.  I have routine of trickle charging every now and then because of my short distance driving pattern.

Yes, non-essential features are purposely switched off to prevent the battery draining so low that it couldn't start the engine.

Keyless entry is also 'delayed' if you haven't unlocked the car for 3 days.  Basically the keyless system stops searching for keys (wasting battery power) until you press the door handle button to wake the module and start it searching again.  But that delay can make it appear like the handle button isn't working unless you give it a second try.

7 hours ago, Magenta said:

Did I understand correctly that a low vehicle battery can affect the operation of the keyless door opening? 

Yes.

If your battery voltage is frequently less than 12.35V then you probably should fit a new battery.

The static voltage does fall below 12v at times (14.6 - 14.8 running) so I guess a new battery is due as it is the original Ford one ten years old.

Will I need to reprogramme anything after that new battery is fitted?

Actually Varta badged Ford.

3 hours ago, Magenta said:

Will I need to reprogramme anything after that new battery is fitted?

No programming needed, only the BMS reset. See the following posts for details of how.

On 3/29/2023 at 8:13 PM, unofix said:

How to reset the BMS method 1                                                                         Search Tag: BMS1

 

 

On 3/29/2023 at 8:14 PM, unofix said:

How to reset the BMS method 2                                                                         Search Tag: BMS2

 

 

Never heard of this.  So you're not turning the fog lamp on/off  5 times, I'm a bit surprised that you press the fog lamp switch 5 times, therefore leaving it on ?  Same with the hazards at 3 times. (Seems method 2 is for Mk 8 Fiestas).

10 hours ago, Magenta said:

Never heard of this.

Well you have now !! 🤣

10 hours ago, Magenta said:

I'm a bit surprised that you press the fog lamp switch 5 times, therefore leaving it on ? 

That is correct. 👍

10 hours ago, Magenta said:

Same with the hazards at 3 times

That is also correct. 👍

10 hours ago, Magenta said:

(Seems method 2 is for Mk 8 Fiestas).

The video was made demonstrating the reset on a Fiesta, but it is the reset process for newer models, typically 2014 onwards.

You also have to bear in mind that some countries like USA do not have mandatory Rear Fog Lights, so method 2 has been adopted by Ford going forward as @unofix said.