Ranger Mods

I was playing with my obdlink app while pumping up the tyres after a beach trip...... I was surprised to see that the battery voltage dropped down to 12.1 V while running the compressor. I've moved the negative clip of the compressor cable from the battery post to the body, to check if the smart change system would read the current draw in this way, but it made no difference, no ramp up in voltage.

Should I connect the compressor clips differently, or is the obdlink app not reading the voltage rise?

Did the amps ramp up?

I was expecting the question.... at that time I did not yet have a working battery current pid. I do now but haven't had to pump up the tyres since then. To be honest I'm wondering if the current in/out pid is reading correctly, as it only registers 3-4 amp in even after startup when the alternator is pulling out 14.5 volts.
I'm using your pid with the equation A-126.

Keep in mind it is current in and out of the battery and not what your alternator is producing to operate the vehicle whilst running including your accessories.

I have the Battery Current, Battery SOC % and Battery Voltage PIDS sitting in my hand. Once my brain is fully operational I will put all 3 up for Torque, OBDLink, SG and UG.

That's great news Stewart, I look forward to that.

I understand what you say about the difference between alternator current output and battery current input, but anyway shouldn't the battery receive a high charge after a cold engine start?

Also, I'm surprised that I did not see a voltage spike when I connected the compressor and the voltage went down to 12.1 volts, with negative clip either on the earth or battery negative post.

Ultimately I'm trying to find out what is the best way of connecting the compressor, connecting the clips on the battery posts seems almost to have the same effect of leaving the engine off while running the compressor, if the voltage reading I get is correct. Maybe next time I'll check with a multimeter too.

Everything will be based on SOC. 80% is target. All you can do is monitor it and try and make an informed decision. I cannot be any more specific. A day will come when I list out every bit of data related to the BMS. Honestly there is so much info and so many other parameters but I class them as dangerous and probably won't put them forward. There are more functions related to BMS in the BCM than anything else.

All you are doing when putting it straight to the battery post is making the SOC go out of sync. Your vehicle SOC will be incorrect from you doing this and will not fix it self. I suggest removing negative battery terminal then doing a full charge then re connecting and doing a BMS reset in Forscan.

If you want to monitor something properly attach a current clamp and get the real figures.

The only way to attach the compressor if to earth to the chassis. No ifs or butts, there is no other way unless you want to end up with a flat battery at some point. My compressor can draw up to 40 ah so I always run the vehicle and I let the alternator do its job. To me the battery is only there to start the car. Forget voltage as it will send you around the bend, what AH you have left in the battery is more important.

Battery Current in out is
Header 726
Mode 22
PID 402B
Math A-127 in amps

Battery SOC
Header 726
Mode 22
PID 4028
Math A in %

Battery Temp approx calculation by BMS
Header 726
Mode 22
PID 4029
Math A/4 in degrees

Cumulative Charge amps into battery Running - Should show cumulative charge value since restart. Untested
Header 726
Mode 22
PID 401E
Math ((A*256)+B)/10

Cumulative Discharge amps from battery Running - Should show cumulative discharge value since restart. Untested
Header 726
Mode 22
PID 4021
Math ((A*256)+B)/10

Too much stressing on the battery subject I think. I have my original 2 year old battery and a 5 year old 120ah AGM. My fridge lasts 4 days without a start, everything is earthed to the chassis. I only run a standard solenoid and do not have dual battery mode enabled. If I air up I start the car and I do not monitor any of the parameters to do with battery. I do run huge cable to the second battery and in a worst case scenario I would jump off the deep cycle although not recommended. My system is basically old school but has been 100% reliable.

I get all you are saying but you are missing the point I'm trying to make; when I was running the compressor the voltage dropped to 12.1 and that happened also with negative clamp connected to the body, so is it really the alternator powering the compressor or is the compressor draining the battery instead, even if the engine is running? If it is the latter, is there any way of preventing this?

I will test again tomorrow now that I have the current and SOC PID's.

PS can you please confirm the correct battery current maths, it's A-127 or A-126 in different posts.

Monitor the current in and out of the battery and this will tell you if current it being used from the battery when the compressor is on.

A-127

Myself and a couple of others will be testing alternator output voltage adjustments over the coming weeks so will let you know the outcome. Accessory current will always be supplied by the alternator unless for some reason you start drawing more current than the alternator can provide.

I have been trying to find an article that could explain properly, ohms law, resistance, current, voltage drop so it will make sense.

eg. The battery also has internal resistance. As the motor draws more current to accelerate and run at a higher speed, the increased current draw will create a larger voltage drop across the battery's internal resistance. The result is voltage droop.

Out of personal curiosity, what is the difference between charging the battery with the negative terminal removed or connected?

And what is the unit of measurement of the total charge in and out? Mine reads 36 discharge and 20 charge.

Probably nothing, but the vehicle is drawing some type of current at all times so logic suggests remove it, charge with an appropriate charger until completed. Re attach and reset the BMS. In the big scheme it is probably not necessary.

Amp in and out. These are only for testing and should match Forscan which should match IDS. It is for trailing and testing. Whether it achieves useful information will be up to you to decide.

I assume you have Forscan working so you should be able to view all those PIDS in Forscan and compare. Whatever is in Forscan is in Fords IDS software, I do the PIDS, I do the calcs but do not have time to test the outcome of everyone.

It's just that the owners manual says that the auto box needs to relearn its shifting pattern after the battery has been disconnected.

It also says that the memorised radio stations will be lost, but it's just those or all the infotainment system settings will be reverted to factory configuration?

I've charged the battery and done a BMS reset. Also, I had a better look tonight at the negative cable and it seems that there is continuity (i.e. there is nothing in between) between battery post and earth on the body, unless the black plastic ring around the battery post larger screw is an inductive ammeter?

Electronic shunt or ammeter. Yes that is what it is and is part of the BMS to measure current in and out. The is also an inductive clamp around the cable from the alternator whick will measure current generated by the alternator.

Ok makes sense. Ive installed the iOS forscan app and the current in/ out figures are much higher than the ones I've seen on OBDLink, can I assume that forscan is the right one?

Forscan should be correct as the info is from Ford IDS.

Some additional info. The 80% SOC is also mentioned here.

Charging System

The smart regenerative charge system primary strategy is stored in the BCM. The BCM receives all of the important information relating to the battery condition from the battery monitoring sensor via the LIN. The BCM calculates and sends the set value needed for the generator charging voltage via the High Speed Controller Area Network (HS-CAN) to the PCM. The PCM then adjusts the value received (if necessary) and sends it to the generator via the LIN. The charging voltage is adjusted depending on various parameters, such as the current level of engine efficiency. The smallest possible set value for the generator voltage is 12.2 volts, while the maximum charging voltage can be anywhere between 14.5 and 14.9 volts. However, when the battery is in a refresh phase, the voltage may occasionally reach up to 15.2 volts. These refresh phases are required when the battery charge status is 80% over long periods of time, which increases the risk of sulfation in the battery cells.

The PCM simultaneously controls and monitors the generator output. When the current consumption is high or the battery is discharged, the PCM raises engine speed as needed to increase generator output. The generator charges the battery and at the same time supplies power for all of the electrical loads. The battery is more effectively charged with a higher voltage when the battery is cold and a lower voltage when the battery is warm.

The PCM turns off the generator during cranking to reduce the generator load and improve cranking speed. Once the engine starts, the PCM slowly increases generator output to the desired voltage.

The PCM reports any charging system faults and sends a message through the High Speed Controller Area Network (HS-CAN) to the BCM. The BCM controls the charging system warning indicator by sending a message over the High Speed Controller Area Network (HS-CAN) to the IPC. The IPC then controls charging system warning indication based on the message from the PCM through the BCM. The status of the PCM charging system warning indicator and/or message is confirmed by viewing PCM PID generator fault indicator lamp (GENFIL). Any charging system fault detected by the PCM results in 1 or more Diagnostic Trouble Codes (DTCs) being set and the PID GENFIL having a status of On. If equipped with a charging system warning indicator, the IPC turns the indicator on or off. If equipped with a message center, the IPC displays a CHECK CHARGING SYSTEM message. In some instances, the CHECK CHARGING SYSTEM message may not display if the ignition is on and the engine is off.

Under certain circumstances, the charging system may have a concern but still charge the battery while the vehicle is running. The LIN is normally used to initiate charging, but with a fault on this circuit, the generator can self-excite, or begin charging on its own. The engine may need to operate at more than 2,000 RPM momentarily for this to occur. The charging system warning indicator illuminates, the corresponding message is displayed and the generator operates in a default mode (approximately 13.5 volts).

Electrical Energy Management System

NOTICE: When any vehicle module is being programmed, connect an external battery charger to make sure the module programming is completed without interruption due to the load shedding feature becoming active. The external battery charger must maintain a system voltage above 13 volts. This may require a charger setting higher than the lowest charge setting. The external battery charger negative connection must be made to an engine or vehicle chassis ground and not the negative battery terminal. If the connection is to the negative battery terminal, load shedding may begin and module programming may be corrupted. After charging has begun, start the engine to clear any load shed states and then turn the engine off and proceed with programming.

This vehicle is equipped with an Electrical Energy Management system which manages battery charging and monitors the battery state of charge. The Electrical Energy Management system software is housed in the BCM. It has the algorithms and control structure for the Smart Regenerative Charging, and Load Shed Control Strategy. The Electrical Energy Management system is equipped with a battery monitor sensor and generator current sensor to monitor the battery. These sensors serve as input to the Electrical Energy Management system software. If the sensors malfunction due to wiring issues or failure, a DTC will be set. In most cases the Electrical Energy Management system functions will be turned off until the sensor operation is restored.

Battery State of Charge

The BCM uses the battery current sensor to keep track of the battery state of charge. During a drive cycle the Electrical Energy Management software adjusts the battery state of charge up during charging, and down during discharge.
During rest periods with the key off, and the vehicle enters sleep mode, the BCM automatically recalibrates the Battery State of Charge. It takes 4 hours in sleep mode, with the vehicle undisturbed, no doors opened or keyless entry buttons pressed, and the total vehicle current draw less than 500mA, to calibrate the battery state of charge to a high accuracy. If the system draw has not allowed the battery state of charge to calibrate over the previous 7 days, the state of charge quality factor changes to identify this and some Electrical Energy Management system functions may be temporarily turned off until a calibration takes place.

Engine Off Load Shed

When the engine is off, and the BCM determines the battery state of charge is below 40% or 45 minutes have elapsed, a load shed message is sent over the CAN. This message turns off the audio/navigation system to save the remaining battery charge. Under this condition, the FDIM displays SYS OFF TO SAVE BATT (without navigation) or BATTERY SAVER — SYSTEM OFF PLEASE START THE ENGINE (with navigation) to notify the driver that battery protection actions are active.

Engine off load shed occurs when the engine is not running, and the ignition is in the ACC or RUN position. To clear the load shed state, restart the engine.

NOTE: To maintain correct operation of the load shed system, any electrical devices or equipment must be grounded to the engine or chassis ground and not the negative battery terminal. A connection to the negative battery terminal may cause an inaccurate measurement of the battery state of charge and may cause incorrect load shed system operation.

When the ignition is in the RUN position and load shed occurs, the IPC message center displays either TURN POWER OFF TO SAVE BATT (base message center) or TURN POWER OFF TO SAVE BATTERY (optional message center). The audio/navigation system will shut down after the message center displays it's warning.

If a fault occurs with the battery current sensor or circuit(s), the only engine off load shed strategy is a 45 minute timer. After 45 minutes have elapsed, the audio/navigation system turns off. To clear the load shed state, restart the engine.

Engine Running Load Shed

When the BCM and/or PSCM voltage is low, with the engine running, a message is sent by the BCM to either minimize or shut down the climate controlled seats, rear defrost, heated mirrors and DATC blower motor to improve system voltage. Under this condition, the IPC message center displays either LOW BATTERY LESS FEATURES (base message center) or LOW BATTERY FEATURES TEMPORARILY TURNED OFF (optional message center) to notify the driver that battery protection actions are active.

Very interesting read.

Do I understand correctly that they suggest to perform modules programming with the key in the off position and an external charger connected, rather than key in run?

Also, where is the load shed circuit breaker between negative battery post and body ground? It looks a continuous path to me. Or maybe they mean that the ammeter on the negative post will sense the current when using the external charger and therefore the BCM will not initiate a load shedding procedure switched on the positive feed?

I think you may find that Forscan asks to turn off the ignition on most module resets as part of the procedure.

YES. "Or maybe they mean that the ammeter on the negative post will sense the current when using the external charger and therefore the BCM will not initiate a load shedding procedure switched on the positive feed?"

Makes perfect sense as it is what I'm doing right now with my 35 amp charger. It is the only way I can sit and program for hours on end with the system shutting down.

Ok, my sessions have never been that long so I have reprogrammed with the key in run as my car shuts down the can bus after few minutes, but always wandered if that wasn't good for the car.

When I wrote my module changes or reset the bms it always asked to turn the engine off and on again after the procedure.

Good call about suggesting to reset the bms, my total charge/discharge values were 36 and 20 respectively (whatever the unit is) which I believe it means that the bms never registered the current drawn by the compressor and must have been a little confused about the soc. now they are 1 and 1 which makes more sense.

What is the best way of connecting an external charger to the battery? Negative to the body ground ok, but where does the positive go to stop the BMS from shutting down power to the ECU's? I've tried to connect to the OBD with a charger to do some programming but it shuts down as soon as I turn the key to off. Also just to charge the battery?

Also, something strange happened last week. Just after doing the BMS reset I took the car to a fabricator to have side rails made and when I picked up the car the right displays had gone back to no RPM gauge and no dysplay selected on the left, as if he had disconnected the battery. He probably had to do some welding on the template while it was attached to the chassis so it might have done that as a precaution, but the battery SOC went down from 91% to 76%, how did that happened?

Positive to positive battery terminal and negative to body of vehicle. You will see a 200mm black cable off the shunt to the body so just use that bolt.

My charger is mounted in the tray. Positive to my solenoid so it charges both batteries when voltage is up and negative to body of tray so when I'm programming the vehicle never shuts down and I can still monitor the battery charge input through whatever device I choose.

Maybe some kind of black magic? He may have had the ignition turned on numerous time just sitting there, who knows. I'm sure he did disconnect the battery at one stage with will make some items change back to the initial display state.

saeb wrote: ↑Mon Oct 02, 2017 8:17 am Positive to positive battery terminal and negative to body of vehicle. You will see a 200mm black cable off the shunt to the body so just use that bolt.

That's what I did, and cycled the ignition on and off as suggested to reset the bms counter, but after a few seconds the connection always drops.

I cannot get the connection to the OBDLink MX to stay on with the key in the off position, no matter how I connect the charger to the battery, any suggestion?

Didn’t think of that. It will go to sleep with ignition off.

I use hardwired dongles so do not have that issue. Have a look in the saeb thread as I put a post there with a 30$ hardwired dongle that works properly with Forscan.