Thanks for posting this material. I am coming up on five years on the battery for my 2019 Lariat, with no battery issues to date, but it is getting up there. Maybe I will wait until the truck is fully paid for, which will free up c. 700.00 USD per month for batteries and mods...The recent ice/cold in North Alabama finally took its toll on my battery and I ended up replacing it tonight at the dealership.
Monday morning when I sat in my truck I noticed my nav screen displaying a "System Off to Save Battery, Please turn ignition off or start engine" message. I have never experienced this message before so I figured a battery replacement might be due soon. I continued to receive this message every time I sat in the truck and leaving work this afternoon the automatic lock on my passenger door did not unlock when I tried to open the door...
Took it right to the dealership and the techs and I tested my battery/alternator. Instantly their battery tester lit up red and displayed the battery bad message. The OEM lariat battery is rated for 800CCA and the tester registered close to 500CCA so that confirmed my suspicion. Testing the alternator we registered a 14.98 - 15.00 V on the terminals and we concluded this was rather high. The technician mentioned maybe I have a bad alternator, but I had another hypothesis. My hypothesis is that our battery management system was overcompensating for the bad battery and that was the likely cause of the high voltage reading. For now my hypothesis looks to be correct; after replacement it registered a nominal 14.30V reading.
My Ranger is a 06/19 build date so I think almost 5 years out of the OEM AGM battery is nothing to scoff at...We replaced it with a Motorcraft BAGM94RH7800 AGM battery with a 36mo warranty.
Lessons Learned:
- Ensure the technician actually plugs up the front connector (grey) back to the positive terminal box or else you will get a power steering dash light ?
- Ensure the technician remembers to reset your automatic windows or else you will be stuck back in the dark ages where you have to hold the button for it to roll up or down all the way (Going back to the dealership tomorrow to get them to reset that free of charge)
- Pay attention to any weird warning messages, it prevented me from being dead in the water this go around. ?
I often see my charging voltage at 14.8-14.9 at the 12v outlet. Sometimes it down to 13.5. It varies a lot, don't know why. Maybe outside temps?
That is what I see also, 14.7-14.8 at the 12v outlet while driving. It is usually 12.7 when not running.
Yes, have not disabled the BMS. Tempted to reset the age of battery value to see if the charging changes.
Yep, at least let them test it to see if the CCAs is abnormal. All of those issues have went away this week with the new battery.
Your Sirius and phone issues sound like you have an old Sync3 build known to develop those issues over time. If you have a build less than 23188, then update. Do not rely on using a wifi connection to check for an available update. Instead, download from the Ford website and do the USB update process.
When charging the battery with the negative lead disconnected, the BMS does not know that the battery was being charged. You should leave the battery connected, hook the negative charger clamp to a ground connection on the body, not the negative battery terminal. This will allow the BMS to see the battery being charged.
