Battery charge using forscan

[kmoore04uk]

Hi all, a while ago there was a thread on here for increasing the battery charge rate using forscan to increase the actual battery charge to near 85/90% For the life in me I can't find this thread. Does anyone know how to do it, if so then please let me know. Cheers 

[ianincheshire]

I think it was this thread

 

[Nathan Buffery]

I couldn't find the option, within Forscan, to alter the state of charge on my focus which is a mk 3.

[JW1982]

Not possible on a Focus MK3/MK3.5. The maximum State of Charge is not configurable on this type of vehicle.

 

[kmoore04uk]

Thanks for your replies. Looks like I have to buy a new battery then. I like the start/stop and it really annoys me that I can't use it. My focus has just about every extra. Including something as silly as  automatic retractable door protectors (which I have never seen before) but they forgot to make the rear brakes disc instead of the drums as they are. How stupid is that?

[Don Ridley]

Does your Focus have a battery monitoring system (BMS)? If there is a module on negative cable clamp assembly (at the battery), you have BMS. BMS limits the state of charge (SOC) to about 80% for fuel efficiency. You can turn BMS off in Forscan (BdyCM main section). Or you can disconnect the small wire attached to the currect sensor on the cable.

This will not increase the rate the battery charges (volts and amps), but it will increase the SOC if BMS is limiting it. As the battery ages the SOC will drop. You can also monitor SOC using Forscan.

[Nathan Buffery]

5 hours ago, Don Ridley said:

You can turn BMS off in Forscan (BdyCM main section). Or you can disconnect the small wire attached to the currect sensor on the cable.

Interesting. Have you done this yourself? I'm wondering if this will effect anything else on the car. I think my preferred option would be to turn it off in Forscan as I reckon disconnecting the wire will cause a DTC. 

[Wino]

6 hours ago, Don Ridley said:

Does your Focus have a battery monitoring system (BMS)? If there is a module on negative cable clamp assembly (at the battery), you have BMS. BMS limits the state of charge (SOC) to about 80% for fuel efficiency. You can turn BMS off in Forscan (BdyCM main section). Or you can disconnect the small wire attached to the currect sensor on the cable.

This will not increase the rate the battery charges (volts and amps), but it will increase the SOC if BMS is limiting it. As the battery ages the SOC will drop. You can also monitor SOC using Forscan.

It's a shame the SOC can't be added to the dash screen like the auto lock can.

[Don Ridley]

21 hours ago, Nathan Buffery said:

Interesting. Have you done this yourself? I'm wondering if this will effect anything else on the car. I think my preferred option would be to turn it off in Forscan as I reckon disconnecting the wire will cause a DTC. 

Yes. Turning off the BMS simply makes the charging system behave like every other vehicle. The PCM will control the alternator output to maiximize the battery charge. 

[JW1982]

Disabling the BMS also requires a different battery.

When the BMS is disabled the PCM is programmed for the charging characteristics of a Silver/Calcium battery and not for the EFB battery that is used on a Ford with BMS. 

[Nathan Buffery]

Might be a stupid question, but is the small box shaped thing on the negative battery terminal the actual BMS, or is it just part of the system? 

[unofix]

2 hours ago, Nathan Buffery said:

is the small box shaped thing on the negative battery terminal the actual BMS,

Yes.

Not much to look at.

[Wino]

51 minutes ago, unofix said:

Yes.

Not much to look at.

Didn't someone post about it a while ago suggesting that's some Fords were fitted with the wrong one ?

[unofix]

16 minutes ago, Wino said:

Didn't someone post about it a while ago suggesting that's some Fords were fitted with the wrong one ?

OK David, you got me !! 🤣

Watch the video (2:34) for details on the BMS. I think it only effects the Focus Mk4

 

[Don Ridley]

8 hours ago, JW1982 said:

Disabling the BMS also requires a different battery.

When the BMS is disabled the PCM is programmed for the charging characteristics of a Silver/Calcium battery and not for the EFB battery that is used on a Ford with BMS. 

You can also change the battery type in Forscan but I don't know if there are options for EFB, Silver Calcium and/or AGB. The battery labels (abbreviations) in Forscan are not defined.