4 hours ago, unofix said:

I can see from the two screen shots that the battery voltage as seen by the Body Control Module (BCM) is a very healthy 14.8V and 14.7V respectfully. Assuming the voltage at the battery terminals is almost identical to those values then the battery is been supplied with a high enough voltage, that if it required charging then the battery would draw current. If the battery is already sufficiently charged then it will not draw any current.

It is very important to realise that you can not force or push current in to a battery. Current is something that can only be drawn by the battery (or other equipment using power).

If the battery is been provided with a good charging voltage (and it looks like it is) and the battery is not drawing current then that is because it is fully charged. After switching off the car and waiting for about one hour if you measure the voltage at the battery terminals it should be about 12.6V (or 12.42V due to Ford's smart charging system). If you find the voltage is much less, then either the battery has come to the end of it's life and is not holding a charge, or there is a parasitic current draw from the car.

So am I correct in thinking that the voltage is always being supplied to the battery when the vehicle is running, and that it’s up to the battery if it takes that voltage on board?

 

18 hours ago, adamfarmiloe said:

So am I correct in thinking that the voltage is always being supplied to the battery when the vehicle is running, and that it’s up to the battery if it takes that voltage on board?

I think you have a misunderstanding between current (Amps) and voltage. Provided the voltage of the vehicle being supplied by the alternator is higher than the standing voltage of the battery terminals then a current can flow from the alternator to the battery and charging will take place. Once the voltage provided by the alternator and the voltage of the battery reaches equilibrium then there will no longer be any current flow in to the battery.

In very general terms you need a voltage of at least 13.6V to be provided by the alternator to be able to charge a regular car battery. This is how the smart charging system is able to control the charging current that the battery draws, by adjusting the charging voltage. If the smart charging system reduces the voltage to that equal to that of the battery then charging will stop. Conversely if the smart charging system increases the voltage from the alternator to a level higher than that of the battery then a current will be drawn by the battery and charging will begin.

Would this affect the operation? In a focus st edition 2.3l - 2021.

And the battery that’s installed 

1 hour ago, adamfarmiloe said:

Would this affect the operation?

Yes. This is a common concern that many owners have found on a range of Ford vehicles.

On some vehicles like the Focus Mk4 there is a setting to adjust the State Of Charge (SOC). It is normally factory set at 80% and for many owners this is the source of frequent low battery issues. Changing the SOC to 90 or 95% works for most people and resolves the problem.

On many other Ford vehicles there is no means for the SOC to be adjusted and it seems that Ford set the battery capacity to a smaller size than the true size of the battery fitted. This appears to have the same or similar affect to setting the SOC to a lower value. Personally I've not needed to change the battery size on my Focus MK4 because I changed the SOC and set it at 95%.

It would certainly increase the charge to the battery if you alter the battery size to 60Ah or as near as is possible from the drop down menu. Don't change it to anything above the true battery capacity or it will get over charged.  After adjusting the size in both settings you will also need to reset the Battery Monitor System (BMS) so that it can re-calculate the battery condition.

 

4 hours ago, unofix said:

Yes. This is a common concern that many owners have found on a range of Ford vehicles.

On some vehicles like the Focus Mk4 there is a setting to adjust the State Of Charge (SOC). It is normally factory set at 80% and for many owners this is the source of frequent low battery issues. Changing the SOC to 90 or 95% works for most people and resolves the problem.

On many other Ford vehicles there is no means for the SOC to be adjusted and it seems that Ford set the battery capacity to a smaller size than the true size of the battery fitted. This appears to have the same or similar affect to setting the SOC to a lower value. Personally I've not needed to change the battery size on my Focus MK4 because I changed the SOC and set it at 95%.

It would certainly increase the charge to the battery if you alter the battery size to 60Ah or as near as is possible from the drop down menu. Don't change it to anything above the true battery capacity or it will get over charged.  After adjusting the size in both settings you will also need to reset the Battery Monitor System (BMS) so that it can re-calculate the battery condition.

 

Just checked the daughters mk8 fiesta 2021 1.0 st_line and this was the battery listed 😂