Low 12v Battery Message

[scott011422]

I'm with the other guys who think you may have a bad auxiliary battery. If it is bad, it would put a constant load on the main battery and easily cause the discharge you are seeing overnight.

To be honest, I have NOT looked at it. Like at all. I've been assuming that because my 75 min shut down draw was only like .01a, That the aux battery couldn't be the cause. Assuming that draw stays constant and i get no updates, thats like 198.6 days to discharge that battery.

I actually ordered a new battery this morning. I charged the battery fully Wednesday morning at work. After sitting a hour with the charger unplugged voltage was 12.79. Drove 15m home. Then another 120M to Chicago. Truck sat maybe 4 hours then 120m home. Got home about 9pm. The next morning, 3:30AM battery was 12.1. Voltage at the battery with the truck running is 14.2. so at the very least that battery should have more or less maintained charge. And as usual. battery only took 2hrs to charge at 3.5a max.

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[PrairiePete]

You can also go into Forscan under BCM and increase the SOC from 80 to 95% and that will help

Where in the BCM spreadsheet (I'm looking at Livinitup's FORscan spreadsheet) will I find this? I've been through the list a couple times and I'm not sure I have the correct line.
Thanks.
Pete

 

[scott011422]

Anyone with a Powerboost, Whats the voltage on the battery with the ignition on. Engine running/Not running Im not sure matters. I'm seeing 14.1sih on the BCM but only 12.8-12.9 on the battery with a multimeter.

 

[Gros Ventre]

12.6 VDC at battery terminals by voltmeter.

 

[scott011422]

Just some more info to throw out there for people.

Ford has been using this exact battery in models from 2015. Looked into some other forums last night and there isn't a lot of bad battery posts. At least until you look at the Gen specific forums for the new models. Then the number of complaints goes up. all with the same issues we see, Which would make since, same manufacture, same software. But there is this though, the Edge, F-150, Expedition, Explorer and Ranger have been using this battery as far back as 2015ish with little to no problems. Now the new gen vehicles with much higher power requirements are STILL using the SAME battery.

Is this battery large enough? Or is there a flaw in Fords latest BMS?

To be fair, There could have been a change at the battery plant at the same time.

But Then again, you have that Video about the BMS from that tech, he is saying that a 10min drive isn't long enough to keep the battery charged in the long run.

While I do take longer trips from time to time. I would same that 80% of my daily driving is short sub 15m trips. Work being my furthest daily at 15 min. Everything else is 5 to 10.

Like I said, I ordered a new battery. Went with the Odyssey ODP-AGM94R H7 L4 and also bought the Odyssey 12a charger. I'll get that all charged up next week when it comes in, Charge up the AUX battery under the seat and reset the BMS with ForScan. After that I will monitor the battery voltage and go from there.

 

[Porpoise Hork]

Where in the BCM spreadsheet (I'm looking at Livinitup's FORscan spreadsheet) will I find this? I've been through the list a couple times and I'm not sure I have the correct line.
Thanks.
Pete

Go into the BCM module (not As-Built) and search for "Battery Target State Of Charge, %" Once found, modify the value from the default 80 to 90-95%. Then write to the truck and cycle the key as instructed. After that drive it around for 20-30 min.

 

[Sky111]

might as well make it 99%...

 

[scott011422]

More updates. I received the new Odyssey battery and I also got their 12a charger.

- Charged the new battery. (inside my office 73 deg)
- Put NoCo charger on truck and topped off both batteries.
-Installed the battery (at this time new batt sat outside for day and a half and was cold. did not check voltage when i installed. I know, My bad).
- Using Forscan, Set SOC to 95% and triggered the BMS Relearn.
- Forscan with engine off showed 12.6 at battery, 74% SOC, no current going to or from battery with 49a coming from the DCDC converter.
- Forscan with engine on showed 14.8 at battery, 74% SOC, 3a on the BMS, (I dont know if that was charging or a drain. Would it be a -3.00 for a drain?) with 57a coming from the DCDC converter.
- Drove it for 30min.
- 2 days later I go and check the battery voltage manually and its at 12.2
- Battery AMP draw with meter is still 1.7A few min after shutting off trucK. Still .05-.08a 75min after shutting truck off. (Needs to be .55 or less with powerboost after 75M per ford)

Friday night, Took out the AUX battery. Charged that. (Was already full).
With AUX removed, charged New battery. was 27 deg out Took maybe an hour to finish charging, let it "Condition" the battery for another 2 hours until i went to bed.
Reinstalled AUX battery, went to bed.

Now its going to be supper cold here through next weekend so I wont be getting anything else done. I don't believe its an overnight issue, But I ordered a logging multimeter and will be doing an overnight amp study. It will also give me the ability to see exactly what the different modes pull. Key too close, Using FordPass to check data, ect.

Another odd thing. Ford battery was 12.05 when I pulled it after sitting all night. I threw a meter on it last night after its been removed for a few days and its now at 12.57. Odd. Its too cold now, But once it warms up next week i'll be putting it on the Odyssey charger and see what happens. I also will be using a power inverter to get a 25A load to check the reserve capacity. Just to go the distance with the Ford battery.

There is another topic, "Ford BMS Battery Monitoring System" where the forum is looking into how the truck is managing and dealing with charging. Its super possible the batteries are going bad because they are being misused by the Ford charging system. It does appear that all 2021+ Ford vehicles are having this same battery trouble. For example, In the Maverick, AGM batteries are sitting at 12.3V and is considered "Normal" That is defiantly not healthy for any AGM.

 

[scott011422]

Just some updates. Having same trouble with new battery. Purchased a logging multimeter and ran it last night. Most of the night was .1 amps or less. A few 30 second spikes of 1.4 amps. Fordpass queries of oil life and tire pressure didn't even show up. Fob activated approach lights were a 4amp spike tapering off over 3 or 4 min. Still suspecting problem with charging. Looks like the truck is not calculating the SOC properly. 12.7v and did BMS reset. SOC now 100%. 2 days later, 12.01 at the battery, SOC 92%.

Still need to do a capacity test, but so far old battery is still looking great. I think with the truck not charging the battery properly, these cold temps are just doing a number on the batteries. At this moment I may end up putting the old battery in. Right now I have to charge the battery every other day to keep the battery over 12.5. I'd rather pull it and store it so it doesn't get damaged.

 

[pavementends]

Glad I found this thread. Went through a lot of the same measurements and all the same head scratching as you did and decided I'd much, much rather spend $200 at Costco for a new H8 AGM than deal with the dealer testing the battery (they couldn't even commit to that taking 1 day! ) only to replace it with another FoMoCo H6, best case. So the day I brought home the new H8 it was 40 degrees F out, I put the brand new battery on a Noco Genius 10 charger (AGM setting) and the charger immediately indicates full. I install battery, reset BMS, manually enter maintenance record in FordPass app, hook up my OBDLink cable and load the app on my phone and then go for a 45 minute drive. By the end of the drive the battery reads 90% SOC. I go to bed. Wake up in the morning, hook up the cable, load the app and it reads 78% SOC and 12.3v (engine off). WTF! Why did a battery 2 sizes larger than spec'ed discharge so much overnight?

 

[scott011422]

Glad I found this thread. Went through a lot of the same measurements and all the same head scratching as you did and decided I'd much, much rather spend $200 at Costco for a new H8 AGM than deal with the dealer testing the battery (they couldn't even commit to that taking 1 day! ) only to replace it with another FoMoCo H6, best case. So the day I brought home the new H8 it was 40 degrees F out, I put the brand new battery on a Noco Genius 10 charger (AGM setting) and the charger immediately indicates full. I install battery, reset BMS, manually enter maintenance record in FordPass app, hook up my OBDLink cable and load the app on my phone and then go for a 45 minute drive. By the end of the drive the battery reads 90% SOC. I go to bed. Wake up in the morning, hook up the cable, load the app and it reads 78% SOC and 12.3v (engine off). WTF! Why did a battery 2 sizes larger than spec'ed discharge so much overnight?

Back at that magic 12.3v. No idea though. Sounds like you are in the same boat im in. Why was is 90% by the time you got back? Truck should of at least maintained the battery!

 

[pavementends]

Back at that magic 12.3v. No idea though. Sounds like you are in the same boat im in. Why was is 90% by the time you got back? Truck should of at least maintained the battery!

So it read ~80% SOC immediately after install and I did the BMS reset doing the flash highs/brake pedal routine (battery icon did flash). So it "charged" the battery from 80% to 90% SOC during that 45 minute drive even though the charger indicated it was full right off the shelf? So weird. I have never once seen my SOC read >90%. Is the BMS reset procedure in Forscan different than the flash highs/brake pedal routine?

 

[Big Dog Daddy]

So it read ~80% SOC immediately after install and I did the BMS reset doing the flash highs/brake pedal routine (battery icon did flash). I have never once seen my SOC read >90%. Is the BMS reset procedure in Forscan different than the flash highs/brake pedal routine?

It shouldn't be any different the dealers use this method all of the time when a laptop isn't available.

 

[pavementends]

It shouldn't be any different the dealers use this method all of the time when a laptop isn't available.

I was expecting the SOC to read 100% when I installed my brand new fully charged H8. Any idea why that didn't happen?

 

[Big Dog Daddy]

I was expecting the SOC to read 100% when I installed my brand new fully charged H8. Any idea why that didn't happen?

Not really sure, when I installed my new battery last week. I had charged it using my pro logics solar. The one all the fdrs guys use. I had left it on agm for 24 hours prior to install. After installing the odvmx+ reported 99% on my trip home from work it breify went to 100% . And now after a few days it's settled in at between 94 and 96 consistently. Except yesterday morning at 5 degrees it said 89% after an hour of driving it was back up to 93% and today it hit 96% again at 51 degrees.

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