Ford Focus MK4 Battery

[spender2611]

Hi Guys,

I am having some battery issues with my Ford Focus MK4 2019 EcoBoost 125 PS.

Originally a 70AH 700CCA Varta Battery was installed. The Battery is dead now, so i have to replace it.

I ordered a litte bit stronger one, a 75AH 700CCA Battery.

What configuration in the BCM for the battery type should I use now?

Varta 70AH 600CCA or the Varta 80AH 700CCA. My new Battery is 75AH 700CCA so in between this two options. I dont know if I should chose the "weaker" or the "stronger" configuration.

Thanks for help!

[Don Ridley]

The battery capacity is not a critical parameter. It is used by the battery monitoring system (BMS) to calculate the state of charge (SOC). BMS tries to hold the SOC around 80%. More critical is the battery type and resetting the BMS (if you have one).

[spender2611]

So when you say type you mean AGM or EFB?

What option should i choose in your opinion with my new 75ah - 70ah oder 80ah in forscan?

thanks for your help

[Ecmbuster]

Read this:
https://www.repairsmith.com/blog/car-battery-types/

The best option is to replace the battery with the identical version.
If it's an AGM version, replace with the identical AH rating and same rules apply to wet cells.
Some and not all models offer a battery version selections for AH ratings. Use those selections only.
Energy Management Systems are very particular when calculating SOC and Battery Life.
Replacement batteries will require a reset to recalculate the type of battery and battery life.

In modern vehicles it is vital to NEVER disconnect a battery while the network is active or didn't enter sleep mode.
The best practice is have the vehicle enter sleep mode and add an external power source to keep the vehicle alive.
Replace the original battery with the replacement. When the connections are made and tightened, remove the external battery source.
Reset the BMS when completed or leave the vehicle for 8 hours undisturbed to relearn the battery SOC and capacity.

Battery Monitoring System.pdf

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Battery Monitoring System Reset.pdf

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[spender2611]

Thanks for all the informations.

ForScan shows me a long list of battery types. What does the battery type change? I just want to know whats the best option.

The reason I am asking is that I already replaced the battery before. Loaded the battery full and made a bms reset. Didnt change the battery type. Now after some months again the battery isnt charging as it should and almost dead. So I ordered again a new battery. I thought it has something to do with the configured battery type.. Loading my asbuilt in the BCM gives me "incorrect value or not configured". So i dont know what was originally confiured.

[Ecmbuster]

You should have saved the original configuration, find the one that matches your controller and write it again.
https://www.motorcraftservice.com/AsBuilt

As mentioned before, the best advice is to correctly match the battery and reset BMS

As for the battery discharging, test the battery draw with an AMP clamp at battery negative, key removed and doors closed.
Wait for the vehicle to enter sleep mode. It can take approx. 20 to 30 min.
Your target value MAX 50mA to MIN 20mA
If the values match (low parasitic drain) then test the alternator using FORScan.
Test the generator duty cycle and output voltage while the engine is running.
Control duty cycle but turning the interior fan ON to OFF and rear window heater ON to OFF.
The values should be seen with duty cycle and voltage Increase / Decrease

Additional: Battery Monitor Sensor

"The Battery Monitor Sensor measures temperature, voltage and current throughput of the battery.
It uses this information to calculate the battery SOC (State of Charge).
To function with high accuracy, the Battery Monitor Sensor must be recalibrated at regular intervals.
A recalibration occurs during a rest period when the battery quiescent current is less than 100mA.
This rest period must last for at least 3 hours.
The longer the rest period, the greater the accuracy.
The timeframe in which a recalibration must take place is seven days.
If the system has been unable to carry out a recalibration within 7 days, the SOC accuracy cannot be guaranteed.
This will result in the Start – Stop and SRC systems being deactivated."

[spender2611]

I have the original Asbuilt - Battery Type: "incorrect value or unconfigured".

So I should leave it unconfigured? Till now nobody knows what this setting actually changes..

[Donny]

Just to confuse things, I have had a 2019 Mk4 since new and it came with a Varta 60/600 Battery. I have not changed the Battery or configured anything in the car but out of curiosity I had a look in FORScan and my Battery is showing as a Varta 43/390 for both Battery Type Factory and Battery Type Normal.

I also wondered why it was set like that, and what effect it has on charging, I doubt is was a mistake. When my car was built it coincided with some other minor changes that Ford made to these cars which I think were to get the emission figures down, including putting skinny but more expensive tyres on my car.

Another side note was that my car had warranty updates to the BCM and the PCM. This coincided with an update to my FORScan Lite App. I always clear the Cache to create a new profile with FORScan updates and when I had a look at the PID's the one for Battery Temperature had disappeared. There is nothing wrong with my OBDLink MX adaptor and everything else works fine so I don't know if the car updates removed the Battery Temperature PID, or if is a glitch with the FORScan update. I may check with an earlier release of the Windows version.

The wrong Battery Type was checked before the car updates.

[spender2611]

Now its getting really confusing.

So with my originally Varta 70AH 700 in ForScan the Battery Type was set to a 52AH Battery. Maybe the Dealership configured it that way.

When I load the factory asbuilt from motorcraft it sets the battery to "incorrect value or not configured".

The Question for me is now: What should I put in Battery Type? 52Ah which was set from dealership or whatsoever? incorrect value or not configured from motorcraft asbuilt or 70AH which is the closest to my battery size?

[Donny]

I don't know, but I would be interested if you find out the answer because at some point I will no doubt have to change mine too and will put to largest one in that fits. I don't have an Extended Licence at the moment to check my As built.

Unless I find out differently I will change the configuration to the new one. I do suspect in my case mine was configured wrong at the factory to reduce emissions. Mine was a mid May 2019 build.