BULGED BATTERY MODULES? NEVER SEEN THAT BEFORE

If you attempt to unbolt the modules while they are hot, you will see them swell up like that.

Whenever you work on a pack, make sure it has cooled 12 hours before you try to unbolt anything

 

That's what happens when the cells are hot or charged while not compressed.That plastic that holds the pack together is to compress the modules tightly so that it can't grow like that. If a single cell got way too hot, like a bad cell and then continued driving, it could blow like one of those and then the rest of the pack wouldn't have the right compression and it is a chain reaction.

There's a lot of energy in those cells...

 

I love seeing stuff like this.

I've seen similar packs from all sorts of not so safe things people try.
- Charging with no compression.
- Charging at too high an amperage, especially at high SOC.
- Running parallel packs without adequate monitoring/maintenance.
- Driving an already damaged pack "just a little farther".

We humans are creative when it comes to ignoring common sense.
What you don't know can really do some damage.

 

What, never?

Hardly ever!





Breezily-designed DIY plugin conversions'll do that....

-Chap

 

So cool.

 

nice potato cam

 

I have a chemistry background. There is a thing called the Pressure Law. Here is the Wiki version: Gay-Lussac's law, Amontons' law or the pressure law was found by Joseph Louis Gay-Lussac in 1809. It states that, for a given mass and constant volume of an ideal gas, the pressure exerted on the sides of its container is directly proportional to its absolute temperature. The higher the temp the more force exerted on it's plastic container. Never charge cells individually and/or in a hot environment. The module is designed to balance cells automatically so there should be no need to try and balance them outside the module. Make sure you clean the battery cooling fan. If you carry your dog in the back seat this will be required more often because it draws air from the vent next to the rear right seat. Find the bad cell(s) and replace. Due to the nature of the beast it will usually be an interior module that doesn't get good air flow. Let the car run until the triangle goes away.

 

I don't think putting them in the freezer will help

 

I never thought of the cool down time but it makes sense

 

Swelling is s lot less common than having the tops blow but both occur. There are some suspect videos on the net and it's always a learning experience with hybrids so don't feel too bad. I got taken to task over a battery change.

 

Top blown off

 

Ahh, yes, the "Ideal Gas Law" aka: PV=nRT

Pressure x Volume = Number (of atoms) x r (constant) x Temperature

Never heard of it

 

Hello sir, i just read this thread and noticed what you replied, I’m dealing with kind of the same issue just no where near this bad. My comutter 2006 Prius 5 had thrown the red triangle again. I have rebuilt the pack twice replacing total of 3 cells. Well i was in a rush when i got home last night to try and replace the new bad cell. I didn’t realize that it being hot would expand. I couldn’t get the pack back together. So i left them disassembled last night. Do you know if the expansion or swelling will go down? Or is it a Permanent problem and i will have to replace all cells to get to back together ? Thanks so much

 

Permanent.