Replace 12V battery in 2017-2018 FFE

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Well-known member
Feb 22, 2019
I did a search and did not see anything, so apologies if I am being redundant.

Has anyone personally replaced the 12V battery in the 2017 or 2018 FFE?
I have the 2017 service manual, and is shows the procedure for the 2016 and earlier.
Namely, the front junction box is in the way of sliding out the battery. The 2016 and ealier do not have the front junction box because it is used for DC fast charging.

So looking at it, seems that I would have to disconnect the charge port HV cable, disconnect the CCS DC fast charge cable from the junction box, remove the 4 nuts at the base, lift the junction box off of the studs to swing it forward and to the RH side of the vehicle. Then possibly unbolting two grounding straps that were by the junction box, and only then could I remove the front of the battery box, move it forward, as it does not appear it will lift up, and hopefully all of this work will have given me enough room to slide the 12V battery forward, up, and out of the vehicle.

Yes, I did not forget disconnecting the 12v+ and 12V- cables and removing the battery brace/bracket.

So anyone personally do this?

I am very much tempted to install a physically smaller battery, so as to have less of a hassle next time.
Sometimes you end up answering your own question.

GOOD NEWS! A Type 26R battery fits just fine, and its a heck of a lot cheaper as well.

I won't bore you of the details of my research, but I picked up a VP-26R 540 CCA 675 CA EverStart battery at walmart for $55. Probably cheaper where you live.

It not exactly the same size, just a tiny bit bigger in all dimensions, but not so much that it does not fit. It does!
As they say, "Pics or it didn't happen!" Sorry that some pics are upside down.

Comparing the lengths.



Weight of Motocraft BXT67R 26.8 pounds

Weight of EverStart VP-26R 26.8 pounds

The hold down bracket fits better on the EverStart than on the Motocraft.

And here is how it looks installed, plenty of space.


To get the Motocraft out, it was pretty much the same procedure as for 2016 an older FFEs, the only additional step was to release a fir tree clip on the panel that lifts up.
That panel folded forward, and this gave enough space to lift the Motorcraft out. The EverStart went in just as easy.

NOTE: Tighten the nuts for the hold down bracket only enough to secure the battery, any more, and you are just bending metal.

So while this EverStart only has a one year free replacement warranty, I am sure a better quality 26R battery could be had for still cheaper than the $140 for the motorcraft.
Yep, just checked Costco, 3 year 26R is $89. If you want to check other sites, sometimes they want a vehicle and not a battery size. Use a 2000 Chevy Metro 4 cylinder LSI 1.3 engine.

And since the battery case is probably the same as for 2012-2016 FFEs, the 26R will probably work for those years as well.
Thanks for the good info!

My 12V was replaced under warranty 2.5 years ago when my TCU killed it. I had planned replacing it with a deep cycle Optima battery when the oem motorcraft gives up the ghost, but with the cost of the battery you found it's really hard to justify the expense of the Optima.
Is there a reason you didn't warranty the battery if there was an issue with it?
Were you past the warranty period? Did it have a prorated warranty attached as I think my 2016 did.
Good question, and unfortunately I do not have a good answer.
The battery was putting out too low of voltage for my liking 12.2v, but it was off and on within an ok value. Sometimes 12.4, sometimes 12.5, sometimes 12.6. Reading up on batteries, supposedly a new 12v lead acid battery puts out 12.7V no load. So if the battery were to be tested and put out 12.6, then who is to say the battery is bad?

In conflict with that thinking, I swear that years ago, a good battery would have 13.1v - 13.2v output. Don't know why it would change, but that value has always stuck in my head. To further support my hazy memory, I have another smaller car battery that I use for starting my motorcycles. That battery puts out 13.15v no load.

To add to the confusion, take a look at this google result:


It says 12.7v, but the picture shows 13.2v.

And also this, in looking through the warranty, I could not find what voltage is considered so low as to authorize warranty replacement of the battery.
12.4v? less? So I thought to just replace the battery, and then deal with the warranty.

It is a shame that they put a regular starting battery into an electric car (pretty much all electric cars), when the best solution is a deep cycle battery.

A starting battery with a no load voltage of 11.9v could probably start an ICE car. But that low of voltage in an EV is probably asking for trouble.
At first I thought I should just pro-actively replace my 12v battery before it inevitably fails, but maybe it's really better just to put one of those "Portable Jump Starter" batteries in the compartment below the rear cargo area where a charge cord goes. .... many models available on amazon or walmart etc. Just be sure to top off the small Li-ion thing up every couple of months to keep it charged.
campfamily said:
If your 12v battery dies, I don't think you'll be able to open the hatch so make sure you can get to it from the passenger section.
Not understanding you. The 12v battery is up front, easily accessible, under the hood.

Funny, when I had mine towed recently due to rain water ingress (SSN) & a blown 350amp fuse, the young inexperienced AAA tow truck driver asked me if he could just "jump it". I told him it is possible an EV could need a 12v jump, its true. He didn't notice it was an EV and looked a bit surprised but I told him, in the future, he may encounter an EV that might need a jump, so he actually stumbled into the right approach to some cases.
Understood where the 12V battery is. But if your jump starter is in the trunk, and you can't open the hatch, the only way to get to it is through the passenger compartment. Have you tried to do that? You may not even be able to get to that part of the trunk with the hatch down, particularly if you have your "coffin" in the lower area.

I don't own my FFE any more, and my son has the RS in Alabama, so can't check to see how hard it is to get into the trunk area from the passenger compartment. But I'm guessing it isn't easy.
campfamily, True, if 12v is completely gone, the hatch release is disabled.
Fortunately the rear seats fold down to let somebody reach into the hatchback area. I tried it and its not too difficult. Could be for some though.
I don't understand. Do you need to replace the accumulator? Or do you have problems with it? If you are not an expert, I advise you not to climb over the trunk to replace the battery. You may not be able to properly disconnect it and connect a new one in a narrow space. The main thing is not to break anything there... It's better to contact a specialist, . The problem was that I bought an old car, apparently, the battery was not new at all and quickly stopped working. I wanted to fix it, but nothing came of it and I just replaced it with a new one.
My battery just failed. I didn't use it for a couple of days and I had to jump it as it was only 9 volts. I drove it for an hour and then when I went to use it 4 hours later, it was really low again. Why does the battery only last just over 3 years in a vehicle that has a large start load? I think it I'd due to the dc to DC converter putting out 14.35 volts. 12 volt FLA batteries want a float around 14.0 volts. Just for an experiment, I had a couple of 10 amp lifepo4 battery packs that I wired in. This has worked fine for a couple of days now, so I ordered 8x 8 amp cells and a balancer. This should give me a 16 ampmhr battery and should be fine. It also weighs about 30 pounds less and takes up half the space in the battery box. This battery is also fine at a 14.35 volt charge having a maximum of 14.6 charge. I am thinking this battery will last me 10 years or so for under $100. I wonder why you don't see more installations like this in electric and hybrid cars that do not need the big starting power. I have seen that Tesla is just now starting to use this type of 12 volt battery in their cars now.
Heima said:
Yep, just checked Costco, 3 year 26R is $89. If you want to check other sites, sometimes they want a vehicle and not a battery size. Use a 2000 Chevy Metro 4 cylinder LSI 1.3 engine.

And since the battery case is probably the same as for 2012-2016 FFEs, the 26R will probably work for those years as well.
Thanks for the tip...The same battery is $110 at Costco as of 8/3/23.. it is a wet Lead acid battery..we'll see how long it lasts... and hopefully the terminals don't corrode.. I coated them with battery corrosion purple spray..