12v Battery Swelling

[footballfalex]

Have a May '24 build but purchased in Nov '24.

Today I was going through to clean the frunk and opened the battery compartment to also give that a dusting if needed. Noticed the 12v is starting to swell. Being it's the OEM and in such short time, this should be covered under warranty, no?

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[B177y]

Have a May '24 build but purchased in Nov '24.

Today I was going through to clean the frunk and opened the battery compartment to also give that a dusting if needed. Noticed the 12v is starting to swell. Being it's the OEM and in such short time, this should be covered under warranty, no?

Yup, that should be covered under your 3yr/36,000 mile B2B.

 

[WaterboyNorCal]

Definitely should be covered under warranty, assuming you are under 36k miles. I just replaced my original 12v battery at 55k miles and after removing it, noticed it was swelling slightly. Unfortunately for me, not a warranty claim anymore.

 

[Heliian]

The new one will also be "swollen".

As long as it meets the spec it should be fine. You can have your dealer test it.

 

[Mach Turtle]

I recently replaced a 4½ year old, not swollen 12V AGM battery in our Mach-E with a new one...which came slightly swollen brand new. Folks on the forums seemed to say slight swelling isn't a sign of trouble. The new battery has been working fine for 3 months so far. As long as the thing passes electrical tests, doesn't leak, and still fits in its cradle, I'd be comfortable with keeping it for a while...though a quick look every few months seems like a good idea.

 

[chl]

Swelling is a sign of pressure build up inside the battery and a could be a sign the BMS is allowing it to be overcharged, or there is some other problem.

Any noticeable swelling is probably a bad sign.

I keep my vehicle batteries on a battery maintainer with an AGM mode. One is now 14 years old, no signs of swelling at all.

The Lightning 12v charging system seems to do some bad things:
1) is seems to allow the battery to become deeply discharged
2) it does not keep the battery topped off at 100% and
3) it allows high charging currents to be applied to the battery (that may lead to the swelling you are seeing)

Over time, this shortens the battery life.

If I saw noticeable swelling of my battery I'd take it for an evaluation and a probable replacement right away if still under warranty.

Then I'd get an AGM mode battery maintainer and keep it on that whenever it is not in use.

Overcharging may be the cause of the battery swelling. It could result in the battery leaking leading to one or more bad cells. That will then cause a drop in voltage and more overcharging by the Lightning charging system.

Deep discharging result in lead sulfates building up on the plates and if the battery is not fully recharged, they become permanent and the battery loses capacity slowly but surely.

Sometimes the sulfates can be removed using a battery restoration mode which uses pulse charging, but success will vary depending.

I recently saw a video about an attempt to restore an AGM battery...interesting...but I'd rather just maintain mine...an ounce of prevention as they say:

 

[Randys Lightning]

I'll put a Optima Blue Top in mine if needed.

 

[21st Century Truck]

I noticed my 2023 OEM 12V battery was swollen to a significant degree this past Fall.

I drive a lot and the truck had just about 80 thousand miles this Fall. This mileage included some Utah, Nevada, SoCal and Arizona mileage this past Summer, so some hot sustained temperatures.

I replaced it because why not? as Winter was approaching.

Over experience with many cars in my shady past, my particular 12V battery's swelling / bulging was the largest I've dealt with. There were no indicators of problems from the Lightning, but still...

 

[Sleazy-E]

I keep my vehicle batteries on a battery maintainer with an AGM mode. One is now 14 years old, no signs of swelling at all.

Do you have specific one you’d recommend? Thanks!

 

[chl]

Do you have specific one you’d recommend? Thanks!

A few of us use the NOCO Genius1, but there are other maintainers that are suitable with an AGM mode.

If you get a NOCO it requires an adapter to use with the standard SAE cords which adds $15 or so to the price on Amazon.

https://www.amazon.com/stores/NOCO/page/8B25D0D1-1EC6-4A21-8956-9D21BF7739D5

See these posts for more info, several threads here about putting trickle chargers on the battery and how to make it easier by adding a trickle charger wire:

https://www.f150lightningforum.com/forum/threads/charging-12v-battery.16979/

I put a wire with an SAE plug on one end through a small hole I drilled next to the charge port hinge where it would not damage anything, and ran it to the battery compartment where I attached it to a fused wire with ring terminals that would fit the 6mm bolts:

The negative connection should be down stream of the BMS sensor so the truck can keep track of how much energy the battery has received:

There is room for the ring terminals on the 6mm posts there on top of the existing connections, just add 6mm nuts.

Of course be wary of sparks and shorts when connecting the wire.

I used about 6 ft of cord with a fuse built in near the ring terminals - I splice together two pieces, one with the ring terminals and fuse, and the other with the SAE plug.

You can feed the wire through the space under the frunk strut when it is opened:

I was able to reach in there to feel where to drill the small hole next to the hings and to route the wire over towards the battery compartment.

Other folks have positioned their maintainer connect elsewhere (see the thread for other ideas).

 

[Sleazy-E]

A few of us use the NOCO Genius1, but there are other maintainers that are suitable with an AGM mode.

If you get a NOCO it requires an adapter to use with the standard SAE cords which adds $15 or so to the price on Amazon.

https://www.amazon.com/stores/NOCO/page/8B25D0D1-1EC6-4A21-8956-9D21BF7739D5

See these posts for more info, several threads here about putting trickle chargers on the battery and how to make it easier by adding a trickle charger wire:

https://www.f150lightningforum.com/forum/threads/charging-12v-battery.16979/

I put a wire with an SAE plug on one end through a small hole I drilled next to the charge port hinge where it would not damage anything, and ran it to the battery compartment where I attached it to a fused wire with ring terminals that would fit the 6mm bolts:

The negative connection should be down stream of the BMS sensor so the truck can keep track of how much energy the battery has received:

There is room for the ring terminals on the 6mm posts there on top of the existing connections, just add 6mm nuts.

Of course be wary of sparks and shorts when connecting the wire.

I used about 6 ft of cord with a fuse built in near the ring terminals - I splice together two pieces, one with the ring terminals and fuse, and the other with the SAE plug.

You can feed the wire through the space under the frunk strut when it is opened:

I was able to reach in there to feel where to drill the small hole next to the hings and to route the wire over towards the battery compartment.

Other folks have positioned their maintainer connect elsewhere (see the thread for other ideas).

Wow, thank you for in depth explanation. Much appreciated.

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