OT: 3.7V tea bags in my Macintosh battery...?

[Bolster]

My MacBook's battery developed a bulge in it, so I replaced it with a new battery. I can only assume this bulge is my fault for leaving the power supply plugged in almost all the time.

I got to thinking, why not just make a "dummy battery" out of the old battery so it doesn't rock (missing one corner of the computer without it) and keep the new one off the charger most the time? So I unbuttoned the old battery to find, I think it was 6 silver "tea bags" labeled 3.7V each. I removed them (wearing a full respirator and safety goggles) to no drama whatsoever, and now have an empty "dummy battery" to put in place. Also removed the electrical connections. Works great.

But I was curious about those "tea bags." Where can I learn more about the "future" of battery cells, which come in the form of squishy little gel packs? Or can someone here give me a brief rundown of what these are? Will we soon be seeing "squishy" flashlights?

I'll admit I was a little disappointed that there weren't Panasonic 18650s in there (see my thread on that topic.)

 

[mdh1979]

Those packs are what lithium polymer cells look like. Apple is one of the first companies to use lipo packs in a computer. RC guys have been using them for almost a decade in planes and helicopters.

Matt

 

[CKOD]

uhh.... link to original?

 

[Bolster]

Those packs are what lithium polymer cells look like. Apple is one of the first companies to use lipo packs in a computer.

Interesting. Any idea why the bulge? At the Apple store they said they had lots of reports of bulging batteries. It's "a known issue."

Likely to be any flashlight uses for lithium poly cells? Because I notice just one would be enough to fire an LED. Nice and flat, they'd make a decent low profile headlamp.

 

[Mr Happy]

Interesting. Any idea why the bulge? At the Apple store they said they had lots of reports of bulging batteries. It's "a known issue."

Likely to be any flashlight uses for lithium poly cells? Because I notice just one would be enough to fire an LED. Nice and flat, they'd make a decent low profile headlamp.

Lithium polymer batteries are well known for bulging or puffing or swelling. Usually it is a bad sign and an indication that the cell should no longer be used. It might be caused by low quality, manufacturing defects, over discharging or over charging. It might simply happen with time and usage. Maybe some experts here can shed more light on the particular causes.

I'd say when large numbers of battery bulging instances are reported as with Apple laptops then there is likely some kind of design defect in the system.

You could use lipoly cells in lighting applications, but since they lack a metal can they are fragile and must be carefully protected from mechanical damage. Also, if they happen to go up in flames they can be rather spectacular. I don't know that I'd want one strapped to my head and risk becoming a human roman candle!

 

[SilverFox]

Hello Bolster,

The RC people found that Li-Po cells bulged when the cells were exposed to rough handling, over charge, and over discharge. A fingernail rubbed against a cell during assembly can result in a bulged cell after the cell has gone through some charge/discharge cycles.

If we assume that Apple has a handle on charging and discharging limits, the problem could be handling of the cells during assembly.

Tom

 

[Bolster]

Interesting.

I have learned that the Apple Battery Bulge often happens after the 3 year mark (out of warranty). Mine was about 3.5 years. The little gel packets are currently sitting out in the Hazmat bin with the broken fluro lightbulb.

 

[mvyrmnd]

There was an extended warranty program for bulging batteries. Even 3 years out of warranty they were still being replaced by apple since they were a safety hazard. If you haven't dismantled the battery, it'd be worth calling Apple to see if they still cover it.

 

[Bolster]

Lots of chatter on the internet that after 3 years, they don't. This was also repeated by the local Mac store. But it seems every once in awhile, someone manages to get a freebie. Whether that's real, or just bragging and they're really under the 3 year mark, who knows. It is the internet, after all, the vast pipeline of mixed valid and incorrect information.

 

[mvyrmnd]

If you get on the phone to them, and manage to get hold of a level 2 tech, sometimes you can talk them into it if you're nice. I've had non-warranty issues repaired under warranty because I sweet-talked a level 2. (I'm a ACMT, so I'm well experienced in this )

 

[BVH]

Puffed Pack - Toss it, Jack!