Considering giving up the fight

[Heima]

Thank you so very much for these photos!
It is very interesting, that at the top of the pack, the liquid appears to be water condensate, yet at the bottom of the pack it is definitely coolant. And the way the silver nuts are corroded, it appears that the condensate has been there for a while. I see that there is a break in a plastic frame at the silver nuts and it almost appears that the brackets for last three cells are "bent up". The white pipes do not look like they have a reliable method of fastening. That one in the center actually looks loose.
It will be interesting to know what else you find.
Thank you again!

[Anti_Climax]

I would imagine being mostly sealed, you'd expect pooled coolant as well as condensed droplets on surfaces inside.

[TDS-03]

Got a little further in teardown. No definitive leak points, but there is very definite swelling in some of the packs. That would seem like a logical cause. There was a lot of pressure built up. Will post some pictures in the morning.

[TDS-03]

Here are the pictures from last night. From seeing where the coolant sits, seems like the swelling is a likely culprit here. My concern is if its safe to reassemble when there are clearly some bad cells here. Is that a fire hazard? Im far from a battery expert. I do have to say Im a bit surprised by the "less than robust" way they have the cooling lines set up. Seems like ok for a low pressure water system for a stationary system, not a car that shuffles and vibrates constantly.

[Anti_Climax]

In a perfect world, I'd say you'd want to swap out those cells. But with the monitoring in place I would expect the car to complain before fire is a real risk.

If nothing else, you might be able to get some cell assemblies from another pack to replace the suspect ones. If I'm seeing things right, that may also address the leaks themselves, yeah?

[TDS-03]

More disassembly and some better news. Following the guide linked earlier, I'm actually removing all the cooling plates and with that, the packd come back together fine. More pictures later. Lots if leaked coolant in the bottom.

[TDS-03]

New pics...
I now have all the cooling plates out, and am in process of wiping down all the stuff. So much coolant...I'm surprised it ran at all. I would estimate a good half inch deep at the bottom of the lower pack, so battery packs just swimming. Will start re-assembly soon.

[jghall00]

Has this coolant leak been observed with the lower pack, or does it always happen with the upper pack? If the latter, does anyone have any insight into why that might be? I have a 2017 approaching 40K, and it's our primary daily driver. It's especially important that the car stay reliable right now with gas prices being as high as they are. I'm getting nervous about keeping the car for a long duration. I would drive it until the wheels fall off, but this swelling cell and pack leak issue seems to arise repeatedly.

[Heima]

So maybe this is something that we could put our collective heads together and try to figure out. Why are the cells swelling?

I found this article online: https://www.dfrsolutions.com/blog/why-d ... ries-swell
and there are 5 reasons listed:

• Overcharge conditions which accelerate parasitic reactions between the electrodes and electrolyte, with release of heat and gases.

• Poor cell quality and design with low anode to cathode stoichiometric ratios, particulate contamination

• Mechanical damage to electrodes induced either during cell assembly or from the product application

• Excessive temperatures (Do not leave your cell phone inside your car)

• Deep discharge of cells

My thinking is:
Overcharge, this seems extremely unlikely, as there is a fair amount of technology going into the charging systems. Unless when the inverter is regenerative braking, its sending a too high of a voltage back into the battery.

Poor cell quality, unlikely, but possible. As formulations and processes improve, the quality will only get better. But was it that bad in 2012, and has the methodology of making the cells not improved with each model year? Or were there battery packs made from cells manufactured the year, two years, or three years before?

Mechanical damage, seems extremely unlikely, as the batteries appear to be fairly well constructed and well protected by the enclosures.

Excessive temperatures, unlikely with the thermal management system, but possible. If the vehicle were parked in the heat of Phoenix for weeks on end, I could see the thermal mass of the battery eventually raising to almost daytime air temperatures. But is that enough to promote swelling?

Deep discharge, this might be it, but how deep a discharge, for how long promotes swelling? We know dealers know nothing of electric cars and will let them sit on the lot and discharge till dead. Most EV have a minimal voltage cut out, but the self-discharge behavior of the battery can still kill it.

Maybe it is the combination of poor cell quality, excessive temperatures, coupled with deep discharge.

Anybody else have other ideas/reasons?

[TDS-03]

Been some time, car went back together. And its still dead. I'm down to the main DTC Error Code: P0A0A; Definition: High Voltage System Interlock Circuit. Somewhere something isnt making a full circuit in what appears to be some 16 segment or so interlock system. I'm giving up. It makes me very sad, but the car is pretty much dead and useless to me now. Truly disappointed in Ford and in this battery design in general after seeing disassembled. I haven't seen other posts about the lower pack. But if its constructed of the same cells, it seems to me that its not going to last.

Anyway...if anyone wants a project or needs spare parts on a 50K mile car, please let me know. I have no clue how to even sell this thing for more than scrap. Just sucks.