Maximizing Battery Life

[TJC]

Update: I charged the battery too 10% SOC according to teh Truck via ScanGauge 3 and both my battery testers. Then via Forscan raised the SOC target to 100%. I can now dynamically view SOC, Charge Voltage, and Charge Amps.

After letting my truck sit for a few days, I drove it 40 miles with the following results:

• SOC climbed back to 100% from 93%.
• Voltage held steady between 14.0v - 14.3v
• Amperage started out relatively high at 18amps but as SOC approached 100% the Amperage charge rate gradually dropped, at 95% it was at 4-5amps and went to 1 at 99%, then to 0 at 100%.

I was quite pleased with the result.

Over the next few weeks I continued to monitor the BMS, and something unexpected began to happen. The SOC target appeared to drop to 94% or 95%. I even reset the BMS and found the same result.

So I unplugged the BMS sensor to see if anything changed. - Nothing did. I lost the SOC and Amps gauges, but reinstalled the sensor to check the results.

I could not charge the battery above 94%!

Last night I charged the battery to 100% SOC over night. Took the truck for a drive earlier today after the truck sat for several hours (not charging the battery). Battery was at 98% after starting and BMS started dumping 5 amps in initially, then dropped to 3, and finally to 1 amp when it hit 99% SOC. It charged to 100% when Amp went to 0... exactly what I would expect. I don't thing I have an electrical problem. This appears to be Software / Firmware related.

I don't like and can't explain this behavior. I going to continue to monitor to see if this charging behavior repeats itself.

Anyone have any insight on what is going on?

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[RangerBill]

Update: I charged the battery too 10% SOC according to teh Truck via ScanGauge 3 and both my battery testers. Then via Forscan raised the SOC target to 100%. I can now dynamically view SOC, Charge Voltage, and Charge Amps.

After letting my truck sit for a few days, I drove it 40 miles with the following results:

• SOC climbed back to 100% from 93%.
• Voltage held steady between 14.0v - 14.3v
• Amperage started out relatively high at 18amps but as SOC approached 100% the Amperage charge rate gradually dropped, at 95% it was at 4-5amps and went to 1 at 99%, then to 0 at 100%.

I was quite pleased with the result.

Over the next few weeks I continued to monitor the BMS, and something unexpected began to happen. The SOC target appeared to drop to 94% or 95%. I even reset the BMS and found the same result.

So I unplugged the BMS sensor to see if anything changed. - Nothing did. I lost the SOC and Amps gauges, but reinstalled the sensor to check the results.

I could not charge the battery above 94%!

Last night I charged the battery to 100% SOC over night. Took the truck for a drive earlier today after the truck sat for several hours (not charging the battery). Battery was at 98% after starting and BMS started dumping 5 amps in initially, then dropped to 3, and finally to 1 amp when it hit 99% SOC. It charged to 100% when Amp went to 0... exactly what I would expect. I don't thing I have an electrical problem. This appears to be Software / Firmware related.

I don't like and can't explain this behavior. I going to continue to monitor to see if this charging behavior repeats itself.

Anyone have any insight on what is going on?

Temperature can affect the charge rate.

 

[TJC]

Temperature can affect the charge rate.

Agreed, But I've been testing this for over a month with fall temps, no extreme changes.

Tomorrow we are going to have our first drop to near freezing over night. With a projected hard freeze Tuesday night of 28F.

Both of my chargers have temperature controls built in. Truck stays in a garage that stays between mid 50's in dead of winter to low 80's in summer.

I really don't think it is the temperature algo impacting this.

I may be wrong.

 

[airline tech]

If I recall - the charge rate appeared to change @ around 45 Deg when I did my initial test procedures.
IDK but you have taken a deeper dive than I have into this.
There is a Batt Temp - (PID) it is not an actual temp as there is not a batt temp sensor.
It is a (estimated-inferred) temp - the same way it is for oil temp.
I did not monitor that temp via live data and was using the (OAT) temp on the dash as my reference. But I do know my results (driving) notations below 45 Deg - it changed.
It may be something in the programming of the alternator PWM control of the charging but can confirm that the Batt Temp (PID) reading is still in play even with the BMS Sensor disconnected.
Something I though was strange at the time but never dove into it any deeper.
It is inferring the batt temp and estimating the temp from the Ambient sensor and possibly the ECT sensor.

 

[dtech]

Lots of variables come into play with batteries and the accuracy of SOC and I don't know if anyone but Ford engineers really understands the specific algorithms used in their SOC calculations.

https://batteryuniversity.com/article/bu-903-how-to-measure-state-of-charge

The linked article mentions that SOC measurements are often misstated by as much as 10%, that's why when folks report their Topdon CCA amps a good deal above the rated CCA I take it with a grain of salt, possible because battery chemistry is a variable affecting output but IMO more likely higher CCA a function of tester accuracy.

 

[airline tech]

I am slowly a bit at a time - taking snap shots of all available PIDs for a reference data table.
I guess I need to do one for Battery & Charging, I am surprised I have not done it yet.

 

[got3fords]

Anyone have any insight on what is going on?

If you ever get to the bottom of this, I will be surprised and grateful. But as I have said, my charge voltages are all over the map, even on the same day with little temp change. But today was a drastic drop in temp, and the drive home showed about mid 13's charge voltage, and no regen charging. Battery is approaching 5 years old.

 

[TJC]

If you ever get to the bottom of this, I will be surprised and grateful. But as I have said, my charge voltages are all over the map, even on the same day with little temp change. But today was a drastic drop in temp, and the drive home showed about mid 13's charge voltage, and no regen charging. Battery is approaching 5 years old.

My charge voltage was constant and has been since I set SOC to 100% and turned off ASS with ForScan. It was the amperage charge that varied. I could not see it real time until I installed the SC3 which allowed me to monitor it... BMS sensor plugged or unplugged didn't change a thing with ASS off and SOC at 100%.

 

[TJC]

My charge voltage was constant and has been since I set SOC to 100% and turned off ASS with ForScan. It was the amperage charge that varied. I could not see it real time until I installed the SC3 which allowed me to monitor it... BMS sensor plugged or unplugged didn't change a thing with ASS off and SOC at 100%.

To further clarify, the only time the voltage changed since setting SOC to 100% and ASS off, was when I recently reset the BMS as if I had a new battery installed. Voltage dropped to 13.6-13.8, then over the next few days it returned to the 14.1 - 14.3 levels.

 

[airline tech]

FYI - I pulled all related PIDs for Battery & Charging except the ones related to - ASS & Remoted start (disabled due to) PIDs

I included the Amb Temp for ref to the Estimated Batt Temp - (Fat Fingered the Start Eng Request)

 

[TJC]

FYI - I pulled all related PIDs for Battery & Charging except the ones related to - ASS & Remoted start (disabled due to) PIDs

I included the Amb Temp for ref to the Estimated Batt Temp - (Fat Fingered the Start Eng Request)

Cool Beans! Was the engine running when you pulled the data? I'm assuming yes.

Remind me again. What is your target SOC set to? 85% IIRC.

Never try charging your truck with the key on with engine off, or immediately after shutting down the engine. You need a BIG charger to make up the amperage draw.

 

[RangerBill]

Never try charging your truck with the key on with engine off, or immediately after shutting down the engine. You need a BIG charger to make up the amperage draw.

Not sure what you mean by this. I do this when doing Sync or map updates with no issues. It saves gas by not running the engine during the update process. I use a 10 amp charger.

 

[TJC]

I've seen several Ford Techs discuss this in detail. The link below is one of the best.

With Key On, Engine Off, this techs F150 was draining 22-23amps from the battery.

So unless you own a charger that delivers >23amps, your battery is still being drained, and you risk overheating your 5amp - 10amp smart charger attempting to maintain the battery with Key On, Engine Off.

Skip to the 8:45 mark to understand where to make connections and why, or the 11:40 mark to see the tech charge at different levels; connected incorrectly and then correctly.

• 5amp (dropped drain to 18amps),
• 20amp (charged at +2 amps),
• 50amps(which charged at +24amps).

Ford BMS Battery Monitoring System: How it Works and How to Properly Charge Your Battery!

 

[RangerBill]

I've seen several Ford Techs discuss this in detail. The link below is one of the best.

With Key On, Engine Off, this techs F150 was draining 22-23amps from the battery.

So unless you own a charger that delivers >23amps, your battery is still being drained, and you risk overheating your 5amp - 10amp smart charger attempting to maintain the battery with Key On, Engine Off.

Skip to the 8:45 mark to understand where to make connections and why, or the 11:40 mark to see the tech charge at different levels; connected incorrectly and then correctly.

• 5amp (dropped drain to 18amps),
• 20amp (charged at +2 amps),
• 50amps(which charged at +24amps).

Ford BMS Battery Monitoring System: How it Works and How to Properly Charge Your Battery!

My 10 amp charger was plenty to keep up in accessory mode while doing the upgrades. I think it was only charging at about 8 amps. Sorry, I disagree with your statement about not using a charger while in accessory mode without running the engine. The tech in the video had deliberately discharged the battery to cause the higher charger currents for demonstration purposes. If your battery has not been discharged, the 10 amp charger is fine for this purpose.

 

[airline tech]

Cool Beans! Was the engine running when you pulled the data? I'm assuming yes.

Remind me again. What is your target SOC set to? 85% IIRC.

Never try charging your truck with the key on with engine off, or immediately after shutting down the engine. You need a BIG charger to make up the amperage draw.

Yes - Engine Running - I actually just bumped the SOC from 90 to 95, no abnormalizes noted - I finally decided I needed to go through the list and pull out all that are charging related for a ref.
I cannot locate an actual SOC and only see Estimated SOC as far as PID Data.

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