Anyone ever re-celled a laptop battery before?

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jdmlight
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Anyone ever re-celled a laptop battery before?

Post by jdmlight » Sat Oct 01, 2011 1:12 pm

So I found this company that will re-cell notebook batteries. http://www.batteryrefill.com/laptops/apple/A1175.phtml Which, of course, got me thinking that I could probably do the same myself for less.

I'm curious to know if anyone here has tried opening a dead laptop battery and replacing the Li-Ion cells inside. Technically it should be as easy as wiring up Li-Ion batteries for a portable, except that you'd re-use the protection circuit from the laptop battery.

The reason I ask is because the battery in my Macbook Pro is not lasting as long as it did. It's far from dead, but I'd like to be able to go longer than 2 hours while trying to squeeze out as much time as possible (minimum brightness, not watching videos, all of that typical battery-life-extending stuff). I'm currently at 450 charge cycles and 3800mah charge capacity left, so I've gotten plenty of use out of it. Many websites say it's a 6-cell battery, but that doesn't add up. It's 10.8v, which means 3x3.7v. Also, it's 5400mah, and supposedly uses 1800mah cells, so 3x1800mah. That would be 9 cells...

The other thing I'm curious about is what type of cells are inside. The battery pack is pretty thin, 14mm including the outer case. A typical cylindrical AA-size Li-Ion battery is 14mm thick, so it wouldn't fit. It's probably flat-packs. But I don't see anything on batteryspace that seems like it would fit. :?

I'm thinking about buyingbought a used Macbook Pro battery on eBay for cheap to open up and inspect for myself. (I don't want to open up my only battery :lol: )

Thoughts?
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jaqiefox
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Re: Anyone ever re-celled a laptop battery before?

Post by jaqiefox » Sun Oct 02, 2011 2:08 am

Ive done so with the old ones with the larger-then-a-cell battpacks which were like slimmer then Cs but twice as long each(ish). I found bad ones and good ones inside the pack, and replaced the ones that wouldnt hold a charge anymore with others. Be careful not to puncture the batteries, of course, and also be careful with shorting them, of course.

The battpacks I messed with were almost always sonically plastic-welded so I had to pry the snot out of them to get them open and bust the welds, and then slice-clean the remaining plastic to clean it up so it would go together again as close, and then glued it back shut again with some epoxy as spot-welds.

I don't feel this is necessary to warn you, but for others considering this, never, ever EVER, EVER use knives, blades or cutting tools like a dremel to get the battery pack open, you will slice into the batteries no matter how careful you are, and that is very, very bad mojo (deadly) even if you escape the flames, the gasses that are released are very toxic.
Jaqie Fox, Genuine girl techie | http://foxtecha.com

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