Aging Battery Question

[Bill K]

I have a '23 Bronco Big Bend coming up on 3 years old in January. I recently took it camping and we experienced our first cold snap in the south and the place I stayed got down to around 18 deg F. Shortly after I started getting messages from the Bronco that the BMS was shutting down some external functions to conserve the battery. Advice put forth by the software was to drive it for awhile and not run the air (no problem with this based on temperatures I was seeing). Note that the Bronco still started okay in its software declared somewhat depleted state. I did bring my trickle charger along, hooked it up, and the alerts went away and external functions (like the touch lock/unlock on the door handles) returned. Flat towed it home and have been seeing the alerts again in the driveway (Bronco is now back on the trickle charger).

This looks to me like the shortened life referenced on the forum here for the AGM battery. Is it worth it to see if it's possibly covered at the dealer under the 3 yr/36000 mile warranty while I have about a month and a half left on it?

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[Ducati1098]

Might as well bring it in and have them test it. It would be covered if it fails.

 

[Dan-O]

Agree with Ducati….take it to dealer before 3/36000

 

[Bill K]

Might as well bring it in and have them test it. It would be covered if it fails.

Thanks. Will do.

 

[RBJRBJ]

Definitely take back to dealer; battery should be covered under warranty. Dealer replaced my AGM battery in my 2023 Bronco after a year. The AGM batteries suffer from a parasitic drain with all the electronics. I keep mine on a battery tender if not using regularly.

 

[Rydfree]

I constantly get these messages from week one of purchasing the Bronco in '23. When I took the Bronco to the local dealer to do the camera and shock recalls a couple weeks ago I asked them to do an oil change even though it wasn't near ready and to have a look at the battery due to this. The dealer I purchased from is 60 miles away so I took a chance since I needed it done quickly for an upcoming trip. I figured I'd give them a few bucks for an oil change for the inconvenience of performing the recalls. They said the battery showed a 30% SOC and there was a drain somewhere but due to my aftermarket equipment they would have to disconnect everything and they could not guarantee things would work when re-connected since they did not originally install them. I told them I'd come pick it up as I'd hate for things to confuse the tech. Mind you that that my aux lights go through the factory switches, the winch has a main disconnect right at the battery and the couple other things have labeled power wires with fuses that attach to the battery studs. It takes about a minute to kill power to everything that has been added and is neater than anything they would ever install themselves. They charged me a $29.99 diagnostic fee. I will not go back.

During my camping trip this past week I plugged in an old battery/alternator tester into the power port inside the center console. Everything looks normal except the alternator output goes completely away sometimes when driving. That may be normal with these new BMS systems when the battery is fully charged, I don't have a clue about these newfangled electronics, lol. The power port stays on for a little while after shutting the Bronco off and I can see the display through the window. I do see the resting voltage go from @ 13.5 down to 12.2 during this short period which seems odd. I can leave it overnight and it only seems to go down to 12.1 at the lowest. I'll probably just replace the battery on my own dime and see if it improves.

 

[dgorsett]

A big tell tale for me was the ASS quit functioning. As soon as I got a battery it , resumed.

 

[Brian_B]

Everything looks normal except the alternator output goes completely away sometimes when driving.

Yup. That's the BMS doing it's "save fuel" thing

Sorry to hear about your dealer - I've heard the same story often. It ~does~ look like parasitic drain if you just look at the battery once with a tester, because the battery SOC will be low. But if you actually go test - the parasitic drain is normal, the battery just can't hold a charge anymore. And you got the "and we don't want to deal with it" line from the dealer - probably (I do not know this, just speculation) because they don't make nearly enough money for the warranty claim to be processed to make it worthwhile, and if they just throw a battery at it the warranty claim would get denied because they didn't do the test.

 

[Bill K]

Returned from the dealer today with a new battery. Bronco failed to start in the driveway with temps in the low 30's yesterday. Put the trickle charge on it and let it go through the night and luckily it started this morning. Likely the last warranty replacement before mine expires in January next year.

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