Bad 12V battery after 3 years

[Je1279]

What are y'all doing to get Ford to replace a bad battery? I know mine is bad because it will float around 11.9V ignition off, which is obviously way too low. My service advisor tells me though that Ford (Canada?) is really sticky on replacing batteries and unless the battery test performed by the dealership tests "BAD" they just keep charging up the damn thing.

Another point towards bad battery - my auto stop/start hadn't kicked in for at least a month. But when I took a small road trip and had the truck on for a few hours, all of the sudden auto stop/start begins working again, even in very cold temperatures. I know that it pretty much only goes off of battery SOC to enable/disable, so this should be further evidence.

Truck is a year old. I shouldn't have to be paying hundreds of dollars out of pocket for a new battery because Ford is being cheap. Any ideas?

I wish I had better news for you, but after hearing about others experiences, I decided that it wasn't worth my time or the increased stress level for multiple dealer visits to replace an item that would likely fail again ~20 months later. Do I enjoy paying $200 for a battery on a vehicle that I purchased new less than two years ago, no. However, after some consideration, it seemed to be the best option for me.

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[Hans Moleman]

What are y'all doing to get Ford to replace a bad battery? I know mine is bad because it will float around 11.9V ignition off, which is obviously way too low. My service advisor tells me though that Ford (Canada?) is really sticky on replacing batteries and unless the battery test performed by the dealership tests "BAD" they just keep charging up the damn thing.

Another point towards bad battery - my auto stop/start hadn't kicked in for at least a month. But when I took a small road trip and had the truck on for a few hours, all of the sudden auto stop/start begins working again, even in very cold temperatures. I know that it pretty much only goes off of battery SOC to enable/disable, so this should be further evidence.

Truck is a year old. I shouldn't have to be paying hundreds of dollars out of pocket for a new battery because Ford is being cheap. Any ideas?

It was actually pretty easy. A week ago the dealer replaced my battery when I took it in. I mentioned I was getting power saver messages and the window module update kept failing. Then they tested the battery with their Rotunda 8000 battery tester and it only was able to get 37% SoC so they deemed it as bad and replaced it.

 

[Gros Ventre]

I wish I had better news for you, but after hearing about others experiences, I decided that it wasn't worth my time or the increased stress level for multiple dealer visits to replace an item that would likely fail again ~20 months later. Do I enjoy paying $200 for a battery on a vehicle that I purchased new less than two years ago, no. However, after some consideration, it seemed to be the best option for me.

...And that's exactly the point: Is it worth your time and trouble to keep trying to hold Ford's feet to the fire or are you better off to just go get another (non-Ford) battery. I can only speculate as to the issue with Ford's Main Batteries. However, when one replaces it, problems disappear. I've mentioned before that I replaced mine 4 months after delivery because of some really odd warnings at 55-65MPH. A drop in, off the shelf, catalog Battery from NAPA. Three years ago and not a peep since out of the truck's electrical system. This includes three Wyoming winters where temperatures can make it down to -40ºF. It is notable that the Aux Battery has never popped up as a problem and mine appears to be problem free... So far.

 

[HammaMan]

What are y'all doing to get Ford to replace a bad battery? I know mine is bad because it will float around 11.9V ignition off, which is obviously way too low. My service advisor tells me though that Ford (Canada?) is really sticky on replacing batteries and unless the battery test performed by the dealership tests "BAD" they just keep charging up the damn thing.

Another point towards bad battery - my auto stop/start hadn't kicked in for at least a month. But when I took a small road trip and had the truck on for a few hours, all of the sudden auto stop/start begins working again, even in very cold temperatures. I know that it pretty much only goes off of battery SOC to enable/disable, so this should be further evidence.

Truck is a year old. I shouldn't have to be paying hundreds of dollars out of pocket for a new battery because Ford is being cheap. Any ideas?

Really depends on what your time and money is worth.
You can find an H8 here, spin the wheel thing and it should apply an 8% off code. Had one of these in a trailer for 8 years (H6) and it was still going strong when I sold it.
https://batterydirect2u.com/product...otive-battery-160rc-900cca-36-months-warranty

 

[Snakebitten]

I humbly request the proper technique for prying the auxiliary battery cover off?

I can see the 6 clip points on my cover, and they coincide with the service manual diagram.
But I can't tell if I should pry out&up?
Or just up?

Don't want to break the plastic. ?

 

[HammaMan]

Put on gloves, run fingers down to the edges that overhang, YANK.
If you have a 90 degree screwdriver it can slip under that edge for prying off. Gets easier the more you do it. Front lifts up, back is quasi hinge style, you can see those sticking down in the image. Front lifts up 40ish degrees and slides to you.

 

[Snakebitten]

You da man HammaMan ?

 

[2Lazy2P]

...And that's exactly the point: Is it worth your time and trouble to keep trying to hold Ford's feet to the fire or are you better off to just go get another (non-Ford) battery. I can only speculate as to the issue with Ford's Main Batteries. However, when one replaces it, problems disappear. I've mentioned before that I replaced mine 4 months after delivery because of some really odd warnings at 55-65MPH. A drop in, off the shelf, catalog Battery from NAPA. Three years ago and not a peep since out of the truck's electrical system. This includes three Wyoming winters where temperatures can make it down to -40ºF. It is notable that the Aux Battery has never popped up as a problem and mine appears to be problem free... So far.

My dealer replaced the original H6 battery with another Motorcraft H6 battery (under warranty). Six months later it, too, started its death spiral. I just replaced it with a Costco H7 Interstate battery. For me it was not worth the aggravation to go the dealer route.

 

[Big Dog Daddy]

You da man HammaMan ?

Is today the day the battle worn AGM gets ejected from the KR land yacht???

 

[Snakebitten]

Is today the day the battle worn AGM gets ejected from the KR land yacht???

Nope.
Keeping the AGM battery under the hood. But I did install a small LFP 25AH Auxiliary battery in place of the little 7AH AGM.

Really curious how much positive influence it will have at "propping up" the AGM.

I "balanced" the LFP before installing it. (Thanks @HammaMan for your guidance. It took 3 nights of 25 milliamps charging to get the cheap Chinese BMS to balance the 4 3.65V cells. But I finally achieved a 14.57V charge.)

After installing the LFP Auxiliary, a couple of hours later the truck is sitting at a nice resting voltage. ?

Underhood AGM is on day 980
I did not reset the truck's BMS

 

[Snakebitten]

Note: Since I didn't reset the BMS, and the truck was disconnected from both batteries for a couple of hours, the Ford PID for Low Voltage SOC was only 81% when I started the truck.

Kinda funny since the resting voltage for the the bank of 12V batteries in parallel was much higher than it was when I disconnected the cables. Just goes to show that the SOC PID is not just a voltage measurement from some digital scale of values.

I believe it takes several hours of unmolested sitting of the truck for the BMS to recalculate SOC?

 

[Snakebitten]

A couple of hours later. (now actually)

I'm pretty sure that answers that question.
Parallel batteries appear to equalize.

Decided to wake the truck and monitor the voltage drop

 

[HammaMan]

I coulda told ya that

Now you just have to use the hvac 5 trick to keep it happy. Enjoy

Did you figure out why I said to wear gloves to open that batt box (hint, the force combined with the seat frame = less flesh on your fingers) I did it twice w/out gloves FWIW, both equally painful.

 

[Snakebitten]

I used an hooked trim tool and it popped right off before my gloved hand had a chance to participate. ?

I left the auxiliary battery box as is, in case I want to revert back.
I mounted the LFP adjacent, but in the end section of the factory underseat storage. Drilled a couple of grommet holes and ran battery cables from LFP to factory cables.

 

[HammaMan]

If you connect up your AGM charger it will refill the LFP w/ a standard charging run.

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