I have a 2013 f150, 40,000+ miles and a 4yr old battery, that has been going into save battery mode. I took it o the dealer ship and they reset it when i go the oil changed. It was fin for 4 days and then it went back into save mode. I took it back up and they found corrosion under the battery cable, they cleaned it and it was fine again for 3/4 days, then the message came back up again. I called them up and told them the message returned, so i took it up again. They couldn't find an issue, so they called Ford. Ford said to check 2 connections. 1 connection was fine, the other one they checked was for the rear camera (my 150 does not have the camera installed) they checked the connector and it fell apart. they covered over the connection. they said that the battery went from 40% to 85% and they thought they fixed it. WRONG 4 days later it's back on again. ANY CLUES??

 

I would be replacing that 4 year old battery.

 

 

This.

 

Do you have any electrical mods that are bypassing the BMS? If you do, it could provide a false reading to the computer and undercharging your battery. My 2013 has 100k miles on the original battery and haven't had any electrical problems. It starts strong, even over this past winter. I also made sure all of my lights/inverters/CBs were wired correctly so that the BMS keeps a proper charge on the battery.

Do you happen to know which terminal your corrosion was on? Corrosion on the negative terminal is often a sign that your battery is undercharged. That would be a clue that your BMS is not accounting for a load on your electrical system.

 

THIS. Unplug that stupid thing and give it a few days. You will be fine.

 

Even without mods, the BMS will not charge fully. Unplug it. I was also getting the low battery message, less often than the OP, just when it got colder. Unplugged mine beginning of winter, never saw the message again. Voltage is now perfect at 14.5 or so while the engine is running.