How-To: remove and replace your 12v battery - recommended at 36 months

[dtbaker61]

when you checked the SOH last week, I presume the battery was connected to the car. Does this in some way make the SOH estimate optimistically high?

I don't know, I just got the cheap little battery tester. It may well have been fooled by all the stuff on the battery terminals in the car. It may take direct measurement on the battery terminals to get a good reading

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[dtbaker61]

See FAQ "Can I replace the AGM battery with a lithium or LFP battery?"

Exactly right. You definitely do not want to swap in a lifting battery in place of AGM. The charge voltage set points are all different and it would not be charged fully or correctly, and if your ambient temperatures outside go below freezing the Li battery would not charge at all

 

[dfcliff]

Yep, was surprised myself. Gerald Jones Ford in Augusta is a great EV dealership. They provide a mobile service which is what they did for my battery replacement. On time and done quickly. They also just did my recall on my car as well. Picked up car and delivered it back to me at 8:30 the next morning.

They must be getting better at it. I lost a lot of faith in them for dealing with my Mach-E the first few times I brought it in.

I tried to have them do the CSP for stuck updates and enabling Blue Cruise. They claimed it was done and enabled Blue Cruise, but when Blue Cruise wasn't working, the techs told me it was only enabled in California and wouldn't work in our part of Georgia. I ordered everything to do it myself the next weekend via FDRS and got it up and running.

The next time was when I was trying to get the second key fob. Evidently they ordered the wrong one, then kept me waiting for almost 3 hours while they tried to figure it out. It took about 3 months from start to finish to receive and program the second fob.

Now if I can just get them to stop trying to offer an oil change on it!

 

[bshaw]

If you buy a 'proper' AGM at month 36, and carry it with you in the Frunk with jumper cables, you will at least have some options if you get surprised.

The reason I am not proactively buying a 12V now (39 months ownership) is because that will start the clock on the replacement battery wearing out as well. In my experience, even batteries in kept in storage and charge maintained will wear out after a few years. The warranty is time-based, not usage-based.
I'd rather wait until the very last day for my current 12V, and buy a fresh replacement at that time. Although if I was frequently going to remote areas where getting assistance would be tricky, I would flip my decision and buy in advance like you say.

 

[Jerrytball]

If you're good at pulling the tub, you can do it in <20 minutes. I spend more time chasing clips that fell into the car. ??

When I first got this car, that was probably the first thing I’ve always heard was the battery, the 12 V battery so this video link I found a long time ago when I first got the car and I’m not saying there was some editing, but this girl did a good job removing the standard battery Without removing the tub. I just keep this video handy you gotta wait or scroll more towards the end, to me I ain’t removing the tub!

 

[LeWe]

When I first got this car, that was probably the first thing I’ve always heard was the battery, the 12 V battery so this video link I found a long time ago when I first got the car and I’m not saying there was some editing, but this girl did a good job removing the standard battery Without removing the tub. I just keep this video handy you gotta wait or scroll more towards the end, to me I ain’t removing the tub!

That’s a neat trick. I’ve clipped the video to the most relevant 40 seconds here:

 

[Jerrytball]

That’s a neat trick. I’ve clipped the video to the most relevant 40 seconds here:

Sweet thanks for editing. She does make it look easy. I’m sorry I’m gullible lol

 

[bshaw]

Sweet thanks for editing. She does make it look easy. I’m sorry I’m gullible lol

Nice find with the 26R being an option for replacement in the MachE. At less than 1/2 the cost, it's something I would consider.

But.... her replacement choice doesn't look like an AGM. Does anyone know if the MachE BMS will properly maintain the non-AGM replacement battery?

 

[Jerrytball]

Nice find with the 26R being an option for replacement in the MachE. At less than 1/2 the cost, it's something I would consider.

But.... her replacement choice doesn't look like an AGM. Does anyone know if the MachE BMS will properly maintain the non-AGM replacement battery?

I would replace it with AGM battery. I found you can get one at rock auto for like 159. I believe that’s where I saw it last not a bad price do it yourself.

 

[dtbaker61]

The reason I am not proactively buying a 12V now (39 months ownership) is because that will start the clock on the replacement battery wearing out as well. In my experience, even batteries in kept in storage and charge maintained will wear out after a few years. The warranty is time-based, not usage-based.
I'd rather wait until the very last day for my current 12V, and buy a fresh replacement at that time. Although if I was frequently going to remote areas where getting assistance would be tricky, I would flip my decision and buy in advance like you say.

the replacement I got from dealership had a sticker that it was 2 months old.... self-discharge rate with AGM is pretty low (sitting at 12.8v), but yes the warranty clock starts when you buy it. So.... if you are a gambler, call the dealership to make SURE they have one on the shelf, and tell them you'll be in to buy one 'in a month or so'.

 

[Jerrytball]

Nice find with the 26R being an option for replacement in the MachE. At less than 1/2 the cost, it's something I would consider.

But.... her replacement choice doesn't look like an AGM. Does anyone know if the MachE BMS will properly maintain the non-AGM replacement battery?

Now I have zero engineering mentality, I’m a flyby the pants kind of guy. But do you know if they ever thought about some type of converter in the car that would allow the big battery to provide 12 V to some of the other components in the car? I know it’s a stretch, but it had to been thought of instead of a 12 V battery?

 

[bshaw]

Now I have zero engineering mentality, I’m a flyby the pants kind of guy. But do you know if they ever thought about some type of converter in the car that would allow the big battery to provide 12 V to some of the other components in the car? I know it’s a stretch, but it had to been thought of instead of a 12 V battery?

It sort of already does what you're saying. Big battery steps in (DCDC) whenever the 12V voltage is getting low.

The big battery has to be isolated while the car is off for safety, so you can never get rid of the 12V completely.

 

[Jerrytball]

It sort of already does what you're saying. Big battery steps in (DCDC) whenever the 12V voltage is getting low.

The big battery has to be isolated while the car is off for safety, so you can never get rid of the 12V completely.

I understand and I always kind of thinking and this is really going outside my electrical knowledge box lol a big capacitor that holds it burst of power to start the car after it’s running, An inverter that only provides 12 V energy the certain parts, lol I have no idea what I’m talking about. Just ignore that.?

 

[jdhzzz]

Now if I can just get them to stop trying to offer an oil change on it!

I cringe every time my dealer sends me one. Not exactly a ringing endorsement of their EV expertise. Next week I send mine in for HVBJB recall. Fingers crossed.

 

[dtbaker61]

Sweet thanks for editing. She does make it look easy. I’m sorry I’m gullible lol

so..... It might be just possible to get the old battery out WITHOUT pulling the tub.... but definitely would be tight fit. If I had to do it again, I'd try it this way.

I would note that the replacement battery in the video is a different size, without same foot-clamp to secure in place, and different ah, which would throw off the firmware parameters for capacity and charging. I would recommend sticking with 12v-35ah AGM H3 size... which you may have to ask Dealership to order.

I wanted to pull the tub to check out a few other things regardless.

Specifically, I wanted to add beefy cables to 12v connection points for charging/export of 12v. But that' a separate project...

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