My BMS/Battery Saver Issue is Finally Resolved, BY ACCIDENT.

[Bobcatou]

I know there have been many people on this forum with the BMS/Saver issue and notices.

With mine, it became clear that it was having to do with my state of charge of my battery. I couldn't get it high enough even after charging my battery with a NOCO 10amp charger. It would max at a SOC of around 60 percent then dip low enough in the next day or two, with or without driving to start giving me the save battery message.

I finally resolved this by accident. I added an accessory harness to my battery so I could just plug in my NOCO to my harness. In adding this harness, I accidently disconnected and reconnected the battery. After this, I saw my SOC at 0%, but I had plenty of power to start the truck, so it was obviously wrong.

I went ahead and did another full charge with my battery charger overnight. The next day the SOC started at 100% percent and settled around 90% in an hour. I checked the SOC over the next few days and it went down 10% the first day, but generally only 3 or 4% after that . This with just with short trips in the truck during the day too. Now it stays around 80%

Seems all is good now. I'm not quite sure how/if/when the BMS reset so I could get a higher state of charge on a full charge, but it appears disconnecting the battery did something. My OBD device still says my battery is 1 year old, so that wasn't affected.

All in all I am happy I am done with this battery issue that isn't really that big a deal than so many other problems I see people dealing with, but it was an annoyance for sure.

I hope this helps someone else, if they are having problems. I get the impression, there are several ways to fix the battery saver issue, I just happened to "Forrest Gump" my way into this one.

A thanks to @Buyer2021 and @Snakebitten for the advice you gave.

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[Cagilber]

This is interesting and something I may have to try. I’ve taken my ‘23 F150 into the dealer twice due to disabling of auto start stop, automatic updates, interior lights, etc etc.

Both times they say state of charge of low (46-60%) but passes the battery test so now replacement is given under warranty.

When questioned by its depleting so fast and unable to maintain a healthy state of charge there are no answers.

I’ve been charging at home a time or two so it re-enables the auto updates, but it seems like I can’t charge high enough to bring auto start stop back (I know. Big deal, I do like that it’s off but it just means something isn’t functioning correctly)

The Last trip the dealer charged to 87% and said auto start stop re-enabled but by the time I picked up the truck later in the day it wasn’t working. Taking it back in at end of July to see what they can find and if the battery state of charge is low again.

 

[Bobcatou]

I continually get up to 100% now on longer trips. I've had no more issues

 

[roadPilot]

Disconnecting the battery for a period of time instructs the BMS to perform a reset/reevaluation to the proper SoC for the connected battery.

 

[Gros Ventre]

The disconnect, as mentioned above, resets things. Although a PB has a second battery, so that needs a disconnect also to do a full-up reset. The Ford programming has set the normal full charge voltage at 80%. This is because the AGM type battery is sensitive to overcharging.

 

[Gooddog1949]

The "PB" refers to a Ford Power-Boost hybrid vehicle, which indeed has a secondary battery, also known as an auxiliary battery. This second battery is designed to power the hybrid's start/stop system and other accessories while the engine is off.

 

[ttnuagmada]

I went the last 14 months I had my first battery doing BMS resets every 6-8 weeks at one point when it would start giving me the message. Never experienced a single actual symptom related to a bad battery though, just the message every few weeks and the power saver stuff that happens at that point. It eventually started getting more frequent though, which is when I pushed the dealer to finally replace it. The replacement has been issue free though, so there was something about the battery that the BMS didn't like, but it wasn't anything that actually prevented it from working fine otherwise.

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