My batteries got wet, what do I do?

[RobCote]

I finally got around to disassembling a 75kWh battery pack from a Model S. In the process, coolant got out of the module cooling loops and into the space between the cells. Most of the modules are fine, but one in particular is looking a little crusty in a few areas. See below. I hit it with a soft bristly brush which removed a fair bit of the corrosion before taking the pictures. Is there something I can apply without disassembling the whole module cell-by-cell to clean them individually? I'd really rather not do that if it's at all avoidable. Any tips are greatly appreciated.

[RobCote]

[tom91]

I would not trust this module, it will most likely start to fail sooner or later. Due to the way the cells are built up and corrosion will start to create cell leakage paths and self discharge.

With temperature cycling this effect will be come worse.

What fluid got on them, Coolant or water(ish)?

[RobCote]

I would not trust this module, it will most likely start to fail sooner or later. Due to the way the cells are built up and corrosion will start to create cell leakage paths and self discharge.

With temperature cycling this effect will be come worse.

What fluid got on them, Coolant or water(ish)?

Well, frig.

It was coolant only.

[tom91]

It was coolant only.

Thats worse as coolant does not "dry", plenty of stories out there of coolant damaged tesla modules. Best to not use them.

[RobCote]

Thats worse as coolant does not "dry", plenty of stories out there of coolant damaged tesla modules. Best to not use them.

While I appreciate your rapid response, could you instead give me the answer I WANTED to hear??

That's crappy. But thanks! Anyone want a bunch of 18650 cells that aren't crustified?

[tom91]

Are you trying to break them?!? no wonder one of them already got damaged.

[RobCote]

No why would I try to break them? That would be totally counterproductive. Could you elaborate to be a little more constructive? One was damaged prior to stacking them, it got coolant inside it as it was still inside the main case, so I’m not sure I follow your logic here.

[tom91]

I see a bunch of coolant puddles. So you did not empty them/blow them empty with compressed air or put caps on it.

you then proceed to rotate them and move them causing the coolant to drop out.

The modules are not designed to have any force in applied in that direction. Also the plastic covers top and bottom cannot take any force. They should be stored flat, or supported by the plastic rails.

[RobCote]

I did blow them out. As you can see, I didn’t cap them. What you see on the floor is what dribbled out over the course of a day following moving them. I cleaned it up.

I understand that they’re mounted flat in the battery pack and that’s what they’re designed for. But sometimes off-label usages are viable. It doesn’t appear to be damaging anything but I’d be happy to look if you can tell me what to check for. You think the yellow plastic flanges on the long sides are susceptible? Or the clear plastic cell holder pieces?

Speaking more broadly, please try to understand there’s not really a manual for how to do all this stuff. Unfortunately, I haven’t been on this forum reading every post since the beginning. I’m trying to learn as I go. That said, I’m not a complete bozo. I’m trying to do my best with what I have.

[tom91]

The thin plastic covers protect the cell fuselink wires. These are super fragile.

Having the modules up on their side not an issue, stacking another module on top means it is resting on the rails, so these are small pressure points.