Bad 12V battery after 3 years

[kb2755]

Mine’s two months shy of 3 years and starting to give me trouble. Gonna try the dealer tomorrow at my scheduled appointment, if they won’t replace it I’ll start shopping for a new one.

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[redline]

Count yourselves lucky mine failed 14 months … dealer would not replace

 

[HammaMan]

Funny thing @Snakebitten - I'd been trying, albeit not aggressively, to get a BMS made so I just kept sending them ideas / needs and there's now a new BMS on the market perfect for making LFP a reality for most of the ConUS. I don't trust them to write the code for it to run, but we're talking capabilities that blow everything else on the market away by a mile. A 20yr+ lifespan starting battery with loads of reserve energy is now within reach. Underhood heat has always been a big variable as a lot of aussies have run into with so called "LFP starting batteries". 3 years is about all you can get with them being abused with the heat, until now.

As for the LFP aux batt, the limitation is still the blower 5 level for keeping it charged. That's a lot for some people to handle. Mine is performing great, waiting for peak winter to come and go and perform a capacity test on it to see where it is. Granted I didn't do that to begin with so I have no way of gauging degradation. I do have another one I guess I can test now before winter arrives but it's still missing a year of operation this one already has on it. Last thing I'd do is assume they're both identical cells internally but it's worth testing I guess. Need to get a computer connected load test unit as the standalone one is just too 'manual'.

 

[kb2755]

Mine’s two months shy of 3 years and starting to give me trouble. Gonna try the dealer tomorrow at my scheduled appointment, if they won’t replace it I’ll start shopping for a new one.

Dealer replaced it today under warranty. No fuss or hassle. They tested it to make sure my dash cam wasn’t the cause but ultimately ruled the battery defective.

 

[Losungen]

My OEM battery is 11 months old (same age as truck) with 48,000 miles on it. I get this warning whenever I do short haul trips or am home for a week or two. Long haul like yesterday (950 miles) - I won’t see this warning for quite a while.

 

[Je1279]

Mine is a few months shy of two years and it is on its last legs. Goes from fully charged to battery protection mode in about 3 days now.

 

[JRonchetto]

A possible compromise would be if you have to replace the battery, you could make a deal with the dealer to swap the battery out of the new truck into your trade in and keep the replacement battery you just bought.

 

[kahancock]

I experienced this in the '21 I bought this past summer. I had a dead battery within the first month of ownership. I messed with it for a few months, put it on a tender, and ultimately, it left me and my daughter stranded, which was the last straw. New H8 and haven't had any issues since.

 

[Jmitchelltfo]

My 2021 has a Motorcraft battery in it (dated July 2024) and as long as my fan is set to 5 or higher my voltage shows 14.2 -15.1.

If I drop the fan speed down, the voltage will normally show 12.6-13.2. This is on my Mx2 Obd reader, so I'm not sure exactly how accurate it is.

 

[HammaMan]

My 2021 has a Motorcraft battery in it (dated July 2024) and as long as my fan is set to 5 or higher my voltage shows 14.2 -15.1.

If I drop the fan speed down, the voltage will normally show 12.6-13.2. This is on my Mx2 Obd reader, so I'm not sure exactly how accurate it is.

That's how it is. Fan 5 trick FTW.

 

[Sammyslab]

I have a 2021 Lariat 5.0. 28,000 miles. Dallas, TX. I bought it used (maybe pre-owned is the woke phrase) out of Iowa in the spring of 2024. It still has the original battery. There have been two long 90 day periods where it was not driven at all.

I keep reading about these bad batteries but am not getting it. I have several cars that I drive infrequently. I put them on a maintainer every two or three weeks until the light turns green, then unplug them. I keep thinking the F150 battery will die based on what I continue to read.
I guess we will see.

When it goes I think I will replace it with the larger battery just because I can, unless someone talks me out of it.

I’m sort of in the same situation as you. I have a 2022 Lariat with a 5.0 engine but with only 6k miles. I bought it new and don’t drive it much as can be seen. Getting beer and cigars! Lol! I’m retired and have nothing but time on my hands.
I keep getting these messages from my truck saying that it’s in Deep Sleep Mode. I put it on my Battery Tender for a couple of days and it’s good again. My question is, should I upgrade to a better battery? Is the OEM battery an AGM? Can’t tell by looking at it. Can I replace it with an AGM? I’m freaking lost here. It’s a H6, I know that. 720AH. That’s about it. I’m not much on batteries. I’ve heard that changing batteries to AGM can be very difficult. Any suggestions? Thanks for your help!!

 

[Je1279]

I’m sort of in the same situation as you. I have a 2022 Lariat with a 5.0 engine but with only 6k miles. I bought it new and don’t drive it much as can be seen. Getting beer and cigars! Lol! I’m retired and have nothing but time on my hands.
I keep getting these messages from my truck saying that it’s in Deep Sleep Mode. I put it on my Battery Tender for a couple of days and it’s good again. My question is, should I upgrade to a better battery? Is the OEM battery an AGM? Can’t tell by looking at it. Can I replace it with an AGM? I’m freaking lost here. It’s a H6, I know that. 720AH. That’s about it. I’m not much on batteries. I’ve heard that changing batteries to AGM can be very difficult. Any suggestions? Thanks for your help!!

Yes, your current battery is an AGM. However, many have experienced that the OEM batteries may be undersized and may not last that long. You can upgrade to an H7 AGM or an H8 AGM as long as you don't have a PowerBoost. Once you replace it, you just need to do the BMS reset procedure and then your good to go.

 

[Gros Ventre]

But!

What’s that auxiliary battery under the back seat that's propping up that AGM? ???

I'm waiting for you to declare your experiments have completed and you have a recommendation.

That battery under the back seat doesn't "prop up" the engine battery. It is auctioneered and supports certain key circuits in the memory and computer. So when its doing its thing it supplies a limited set of stuff.

 

[Sammyslab]

Yes, your current battery is an AGM. However, many have experienced that the OEM batteries may be undersized and may not last that long. You can upgrade to an H7 AGM or an H8 AGM as long as you don't have a PowerBoost. Once you replace it, you just need to do the BMS reset procedure and then your good to go.

I appreciate your input but to be honest, I have no idea what a BMS Reset is. I’m an old fart and all of this stuff flies over my head unfortunately. Is this something that I should take to the dealership to have changed out and reset?
Thank you again!

 

[Je1279]

I appreciate your input but to be honest, I have no idea what a BMS Reset is. I’m an old fart and all of this stuff flies over my head unfortunately. Is this something that I should take to the dealership to have changed out and reset?
Thank you again!

No worries. I stole this from one of @Kanuck's posts.

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