Battery dead in less than 6 months

[Indarkness]

Picked up my WT end of March 2023. We had a hurricane last week here in FL, we got luck as it went right passed. Only got a day and a half of rain. Went to move the bronco and it was very slow to start. The next day, wife was able to take it to work and make it home. The next day Friday the battery was dead. Good news is the dealer has a mobile service van and they replaced the battery same day.
I guess it happens, but I’m really surprised that the expensive battery would die in less than 6 months. Florida is hot and I brutal on batteries. I think the worst luck I have had is 15 months with a free replacement but 6 months is a new record. On a test drive the voltage was 14.7 at the start of the drive and 14.4 at the end of a drive. This was Wednesday before the wife took it to work on Thursday. Not sure if there is an over charging thing or something else to prematurely kill the battery. Either way the situation was resolved NBH the dealer and all seems back to normal.

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[TXBronco1313]

First, glad to hear the hurricane did not do the anticipated damage! As far as the battery, this is weird. I'd say the weather does play a roll in draining a battery but I don't know about the weather killing a 6 month old battery.

I have a Ring dashcam connected to my Bronco and plugged straight to the OBD II port for about 5 months now and so far no complaints about the battery.. Could be a bad battery from the factory? Let's see what the others think

 

[Ducati1098]

Picked up my WT end of March 2023. We had a hurricane last week here in FL, we got luck as it went right passed. Only got a day and a half of rain. Went to move the bronco and it was very slow to start. The next day, wife was able to take it to work and make it home. The next day Friday the battery was dead. Good news is the dealer has a mobile service van and they replaced the battery same day.
I guess it happens, but I’m really surprised that the expensive battery would die in less than 6 months. Florida is hot and I brutal on batteries. I think the worst luck I have had is 15 months with a free replacement but 6 months is a new record. On a test drive the voltage was 14.7 at the start of the drive and 14.4 at the end of a drive. This was Wednesday before the wife took it to work on Thursday. Not sure if there is an over charging thing or something else to prematurely kill the battery. Either way the situation was resolved NBH the dealer and all seems back to normal.

I wouldn’t worry too much about the voltage gauge numbers. Normal charging range can vary from 12.2 all the way to around 15.2 depending on a lot of criteria

 

[TCB-1]

I wouldn’t worry too much about the voltage gauge numbers. Normal charging range can vary from 12.2 all the way to around 15.2 depending on a lot of criteria

Yup, the AGM battery charging characteristics is quite different than traditional lead acid. Kinda weirded me out the first time I saw my Bronco's amp gauge go from 12.3 to 14.7! But after investigation, it's normal.

 

[Roger123]

I would say you just got a bad one, it happens. Now if it happens again maybe you have some weird parasitic draw.

Volt meter being all over seems to be normal. I routinely see 12.2ish to 14.

 

[KABQ]

Last winter I routinely saw charging voltage of 15.0-15.2 and spent a whole lot of time worrying about it because I've never had an AGM battery before. After awhile I Learned to Stop Worrying and Love the Bomb.

The smart charging system does its job well even if it freaks out old lead acid guys like me, so your problem is likely the battery itself.

 

[Fmuguira]

So our Broncos have AGM batteries from factory in lieu of lead/acid?? If so, I didn’t know that. I typically replace lead/acid with AGM when 4-5 years elapse just to minimize fender, battery mount, and corrosion risks.

Regarding your battery, get dealer to warranty it; 6 months “”ain’t right” !!!

 

[flip]

Short tripping will kill batteries (taking more out than putting back in). Likely just a bad battery, if the AGM become discharged, especially from sitting, they're nearly impossible to bring back. Is this abnormal or something to be concerned about? No.

 

[Indarkness]

Short tripping will kill batteries (taking more out than putting back in). Likely just a bad battery, if the AGM become discharged, especially from sitting, they're nearly impossible to bring back. Is this abnormal or something to be concerned about? No.

Already has 6500 miles on it. Wife drives it almost every day. I think the longest it has ever sat was 3 days. Dealer did the mobile battery replacement and she seems to be fine now. My thoughts are it was just a bad battery. If this new one dies in 6 months, I will take to the dealer and have them investigate. I think the odds are against 2 of the AGM batteries going bad in 6 months.

 

[flip]

Already has 6500 miles on it. Wife drives it almost every day. I think the longest it has ever sat was 3 days. Dealer did the mobile battery replacement and she seems to be fine now. My thoughts are it was just a bad battery. If this new one dies in 6 months, I will take to the dealer and have them investigate. I think the odds are against 2 of the AGM batteries going bad in 6 months.

Agreed. While we don't have a huge number of sub 1 year batteries die, we had one a few weeks ago dead off the transport at 5:00pm when everyone was leaving. I'm sure Ford tracks failure statistics for each battery by part number, mileage and age but they don't publish that for outside consumption that I know of. Sitting for long periods, short tripping and heat are probably the top 3 killers of most automotive batteries. With lead acid, you could usually go through charging cycles and they'd come back, maybe not fully but they would be usable again. The AGM seem to be nearly impossible to even get back once a deep discharge, usually from long periods of inactivity. We tell people who store vehicles or have long periods (week or more) of no driving to put a battery tender on them because of the amount of draw constantly on them even after going into sleep mode.

My suspicion is your battery just had an internal defect. If you do have more starting issues you may have an abnormal draw, just make sure any accessories like chargers, dash cam or other electronics aren't plugged in. That could be a source of draw if they were wired into a circuit that's hot all the time. We've seen modules not powering down and causing draws too but those are generally fairly easy to track down.

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