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2021 Lariat Battery Replacement Questions (Dealership vs. Self)

endzone_truck

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Hi,

Looking to replace my stock H7 battery with an H8. THere are so many confusing threads on this so this is why I am posting. If there is a video or a guide that would help kindly share it with me.

- Should I do this myself? I don't have any forscan hardware, and don't even own a windows laptop FYI
- If I get the dealership to replace it will they make the necessary changes to the SOC or total charge capacity of the battery? How can I verify that they have done this?
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endzone_truck

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You don't need Forscan. Just install the new battery (fully charged) and do the simple BMS reset procedure. You should be good to go after that.
Thanks Jel1279. So this link explains it.

But how does the mainframe inside the truck know that it’s an H8 as opposed to an H7?
 

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But how does the mainframe inside the truck know that it’s an H8 as opposed to an H7?
It doesn't, and even with FORScan (or, the dealer's FDRS, IIRC from reports here) there's no parameter value for making an H6-7-8 distinction 'known' to the truck on 2021+ model years (Gen 14 F150).

I'm sure someone will correct me if I'm wrong about that .....
 
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endzone_truck

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It doesn't, and even with FORScan (or, the dealer's FDRS, IIRC from reports here) there's no parameter value for making an H6-7-8 distinction 'known' to the truck on 2021+ model years (Gen 14 F150).

I'm sure someone will correct me if I'm wrong about that .....
What I’ve gathered is the H7 holds a certain amount and the H8 holds more.
The truck is configured to charge an H7 and not an H8
 

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Best I can tell, @Buyer2021 is correct. The models prior to 2021 had a value you could change using Forscan for the battery size. For the '21+ though, the locations are listed as not used. Some have experimented with entering different values into these locations, but to my knowledge, nothing has definitively shown that it makes any difference.
 
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For the purist, do the battery reset procedure. But the system will figure out things on its own. In my case when I decided to replace my OEM battery (@4 months), I just pulled into a NAPA store, got a new catalog list battery (wasn't then smart enough to go thru the H-7 or H-8 drill), dropped it in and went about things. Never a peep out of the system and that was three Wyoming winters ago...
 
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endzone_truck

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For the purist, do the battery reset procedure. But the system will figure out things on its own. In my case when I decided to replace my OEM battery (@4 months), I just pulled into a NAPA store, got a new catalog list battery (wasn't then smart enough to go thru the H-7 or H-8 drill), dropped it in and went about things. Never a peep out of the system and that was three Wyoming winters ago...
Thanks Gros Ventre.

I don't have any issues but the car is almost 4 years old with only 26,000 miles. So it sits around a lot; 5 - 7 days at a time in Ontario winters and then I need it to go anywhere from 200 - 1000 miles.

The last thing I want to do is be stuck hunting in Keewatin and have a low battery. I tend to use a lot of the power assist features as well.
 
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endzone_truck

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It doesn't, and even with FORScan (or, the dealer's FDRS, IIRC from reports here) there's no parameter value for making an H6-7-8 distinction 'known' to the truck on 2021+ model years (Gen 14 F150).

I'm sure someone will correct me if I'm wrong about that .....
This is very insightful information. Thank you Buyer2021.
 

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Those of you who have purchased an H8 at Costco, is there a part number you can relay? I'm afraid that if I just ask for an H8, they won't know what to sell me.

Thanks in advance!
 

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H8 AGM is the way unless you have a Powerboost then you need an H7 AGM. Just did this for my Lariat @ week ago. Battery sensor reset instructions is in owners manual.

Ford F-150 2021 Lariat Battery Replacement Questions (Dealership vs. Self) Image 12-4-24 at 09.25
 

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Those of you who have purchased an H8 at Costco, is there a part number you can relay? I'm afraid that if I just ask for an H8, they won't know what to sell me.

Thanks in advance!
H8 AGM vs H8 lead acid. Truck is designed for AGM batteries. Me I picked mine out off the rack at Wally World.
 

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How about "IT manager"
It doesn't, and even with FORScan (or, the dealer's FDRS, IIRC from reports here) there's no parameter value for making an H6-7-8 distinction 'known' to the truck on 2021+ model years (Gen 14 F150).

I'm sure someone will correct me if I'm wrong about that .....

Mostly likely this ^^

The truck shouldn't know, nor care what the capacity of the cell is. It makes no difference anyway. The battery is 12V right? That's all it's looking for.
As long as its volt meter reads >= ~12V & <= ~14V you're good.
If it is < 12V, probably not so good.

Voltage does not equal capacity. And capacity is not as simple as measuring how much liquid is in a fuel tank.
If you've got a bunch of powered stuff on your truck, and the battery isn't lasting. Consider adding a battery, instead of making the current one only slightly larger.
 

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The truck shouldn't know, nor care what the capacity of the cell is. It makes no difference anyway. The battery is 12V right? That's all it's looking for.
Actually, the battery Monitoring Sensor and the Electrical Energy Management system sense and use both voltage and current (amps) to determine the charging curve (as with most sophisticated chargers, both volts and amps are variable when charging).

Perhaps of interest is the attached, which though specific to the 2.7 / 3.5EB, is the same for the 5.0.

None of that Workshop Manual section makes it clear whether or not an assumed 'capacity' (Ah) of the battery, which is what differs by battery size, is a factor in any of the pertinent Electrical Management system algorithms (?).

Battery size may well be moot when it comes to optimizing a charging profile. As evidence I note that none of the sophisticated stand-alone (e.g. NOCO) chargers require any info about battery size (distinct from battery type), but they manage to optimize charging quite nicely.
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