How to hack the laptop battery

[etc]

http://www.metacafe.com/watch/479447/laptop_battery_hack_dont_buy_a_new_one/

Of course you can use the Li-Ion cells in your superlight.

 

[Fallingwater]

Can't stand the guy. He keeps rediscovering hot water and making a big deal of it.
Has he even bothered to check eBay before getting the bare cells? It's likely he'd have found a replacement for a whole lot less than $109, possibly as low as he paid for the bare cells.

 

[kuksul08]

Can't stand the guy. He keeps rediscovering hot water and making a big deal of it.
Has he even bothered to check eBay before getting the bare cells? It's likely he'd have found a replacement for a whole lot less than $109, possibly as low as he paid for the bare cells.

But... he... talks so clearly and quickly. That must mean he's all-knowing. :eek:

 

[65535]

IMHO he's full of it. I'll admit that better cells 2200MaH+ can be had for around $6 per cell and can be used to increase battery life on some laptops. But for a lot of laptops it's important to use cells with the same capacity because they are pre programmed with internal measurement software and hardware that is set for certain capacities.

 

[kramer5150]

That is EXTREMELY dangerous if you are not VERY cautious and exercise safety first. The 7-8 laptop packs I have taken apart have nothing but thin rubberized tape separating + from -, a distance of only a couple mm. If you are not extremely careful you can short the circuits.

Often times with these packs only 1-2 cells are bad causing the pack to poop out. The remaining cells are near fully charged, alive, healthy, kicking and capable of starting an explosive lithium fire. All it takes is a slip of your knife or shorting wire cutters across the circuit and.... :poof: There are NO fuses and the cells themselves are unprotected so the circuit is HOT HOT HOT between the cells!!

I was hoping this pack had 10440s.

 

[Guy's Dropper]

Where did you get all of those laptop battery packs?:eek:

 

[Fallingwater]

But... he... talks so clearly and quickly. That must mean he's all-knowing

You joke, but I'm pretty convinced that his fame comes in great part exactly from that. Had he been one of those who add a lot of "hmmm" "errr" and so on in their movies, spreading his crap on metacafe would have earned him a lot less money.
I still can't figure out what the hell the Make Magazine people were smoking when they hired him.

IMHO he's full of it. I'll admit that better cells 2200MaH+ can be had for around $6 per cell

Make that $6.5 per pair (Trustfires on DX have just had a very pleasant price drop).

But for a lot of laptops it's important to use cells with the same capacity because they are pre programmed with internal measurement software and hardware that is set for certain capacities.

Eh, not really. I just modified my EeePC's battery by adding two cells to the pack, and while the circuitry does seem to get a slight bit confused, this doesn't cause problems.
Some other guy has just done a similar mod with a lot more cells, and he reports that the battery gauge is now severely screwed up (the laptop works for most of the charge with the gauge reading 0%), but the whole thing still works as intended.

That is EXTREMELY dangerous if you are not VERY cautious and exercise safety first. The 7-8 laptop packs I have taken apart have nothing but thin rubberized tape separating + from -, a distance of only a couple mm. If you are not extremely careful you can short the circuits.

You don't necessarily need to bother with that. Just cut the tabs at the cell terminals and the circuit is de-energised.

All it takes is a slip of your knife or shorting wire cutters across the circuit and.... :poof: There are NO fuses and the cells themselves are unprotected so the circuit is HOT HOT HOT between the cells!!

While the danger of shorting the pack is definitely there, a slip of your knife or accidental contact with wire cutters is unlikely to do much of anything. LiIon cells really dislike shorts, but once someone does short a pack the "zap!" noise and spark(s) are very likely to make them retract the tool at once. The short is thus very very short, and definitely not enough to start a fire.
But if you drop a tool on an open pack and don't notice, then all bets are off...

http://img264.imageshack.us/img264/6060/dscn0464mn4.jpg

You could put all those in series and zap people with them :p
Where do you get the packs?

I was hoping this pack had 10440s.
http://img510.imageshack.us/img510/1786/dscn0465ea4.jpg

Slim laptop packs almost always have prismatic cells, or sometimes even LiPo ones. I guess the space premium that cylindrical cells need is not an option when size is that much of a concern.

 

[kramer5150]

I have a lot of experience DIY tweeking and working with electric circuits from my involvement in car audio, RC cars, and guitar tube amps. I was very careful and cautious, yet I still managed to screw up. I work on these outside on my brick patio so if the cells do flame up the flames don't ignite to anything of value (except possibly me;)). I can't imagine the average joe attempting this kind of a mod.

I was cutting a segment of wire to free up a cell and as my cutters were cutting through the wire a sharp backside edge of my wire cuter sliced through the cell heat shrink and shorted + to -. It sparked, smoked and melted the heatshrink for a moment. I have since dremel'd my wire cutters to remove all sharp edges and burs.

Second incident occur'd when I tried to cut through one of the metal strips with my wire cutter. I was not careful in observing the circuit and had not noticed there was a wire behind/beneath the metal strip. When I cut the strip I shorted the wire and strip!!! WOOOHOOO!!! the wire welded to the strip and became a fuse-link between + and -. It turned red hot and lit the insulation, tape and adhesive on fire. I keep a wet towel at my side during the procedure, so I ousted the flames easily.


"You don't necessarily need to bother with that. Just cut the tabs at the cell terminals and the circuit is de-energised."

Easy to do in theory, not so easy in the real world. The way the packs are assembled, taped and glued together you simply can't access those points in the circuit without pulling the cells apart and opening things up far enough to get a wire cutter "in there". Thats partially how I made the two mistakes listed above... trying to shove my wire cutter in between and beneath tight areas to access the points to disconnect the cells.

I get the packs from the recycle program at work.... one mans trash...:o

The intent of my posting is not to discourage the idea of modding / replacing / salvaging ells, but more to alert CPFers who do take on such a project. There are safety concerns and an element of risk in doing this. The video dismissed the safety concerns all together and made it look no more dangerous than reloading AAs into a VCR remote. Furthermore, the pack used for the demo is unusually well laid out, with cells perfectly side by side.... very low risk of + and - contacts being close to each other. I took apart a toshiba pack just like that, for its 17670 cells and it was relatively easy.

 

[Fallingwater]

I can't imagine the average joe attempting this kind of a mod.

I agree on this. Worthless as they are, the other contributions by "kipkay" are at least more or less things anyone with opposable thumbs would be able to do. This isn't.

Second incident occur'd when I tried to cut through one of the metal strips with my wire cutter. I was not careful in observing the circuit and had not noticed there was a wire behind/beneath the metal strip. When I cut the strip I shorted the wire and strip!!! WOOOHOOO!!! the wire welded to the strip and became a fuse-link between + and -. It turned red hot and lit the insulation, tape and adhesive on fire. I keep a wet towel at my side during the procedure, so I ousted the flames easily.

Must have been an interesting sight :D it wasn't a lithium cell, was it?

Easy to do in theory, not so easy in the real world. The way the packs are assembled, taped and glued together you simply can't access those points in the circuit without pulling the cells apart and opening things up far enough to get a wire cutter "in there".

Hmm. I remember doing exactly this on my two laptop batteries (one from Acer and one from (if memory serves me right) HP). Then again, I've taken apart two packs and you have taken apart about a zillion, so I'm going to say you're probably right. :p

The video dismissed the safety concerns all together and made it look no more dangerous than reloading AAs into a VCR remote.

True. There should really be a way of reporting those videos and have them removed.
Hmm. Maybe there is? :thinking:

Edit: there is in fact a "report" link. I'm going to report this and hope the MEtaCafe people care enough about safety to take it down.

Edit 2: the "report" link does nothing for me, I keep clicking it but no way of reporting the video actually comes out. :/

 

[Bolek]

Cut wires one by one. Some wires in a laptop bat pack are in pair; separete them and cut one after another.
at the end :If some batteries are under 2.5V never charge them with a standart charger (dispose them or recharge the at a very moderat rat like 50mA until it get 3.5V then charge them under supervision on your Li Ion charger).
Get fun with the gulty free lumens.

 

[kramer5150]

Cut wires one by one. Some wires in a laptop bat pack are in pair; separete them and cut one after another.
at the end :If some batteries are under 2.5V never charge them with a standart charger (dispose them or recharge the at a very moderat rat like 50mA until it get 3.5V then charge them under supervision on your Li Ion charger).
Get fun with the gulty free lumens.

OK thanks!! I just recycle the cells below 2.5V, usually 1-2 par pack.

"Must have been an interesting sight it wasn't a lithium cell, was it?"
Yes sir-ee :laughing:!! I had no desire to keep those particular cells, even though it was only the wire and insulation that flamed :crackup:.

 

[LuxLuthor]

I have a lot of experience DIY tweeking and working with electric circuits from my involvement in car audio, RC cars, and guitar tube amps. I was very careful and cautious, yet I still managed to screw up. I work on these outside on my brick patio so if the cells do flame up the flames don't ignite to anything of value (except possibly me;)). I can't imagine the average joe attempting this kind of a mod.

I was cutting a segment of wire to free up a cell and as my cutters were cutting through the wire a sharp backside edge of my wire cuter sliced through the cell heat shrink and shorted + to -. It sparked, smoked and melted the heatshrink for a moment. I have since dremel'd my wire cutters to remove all sharp edges and burs.

Second incident occur'd when I tried to cut through one of the metal strips with my wire cutter. I was not careful in observing the circuit and had not noticed there was a wire behind/beneath the metal strip. When I cut the strip I shorted the wire and strip!!! WOOOHOOO!!! the wire welded to the strip and became a fuse-link between + and -. It turned red hot and lit the insulation, tape and adhesive on fire. I keep a wet towel at my side during the procedure, so I ousted the flames easily.


"You don't necessarily need to bother with that. Just cut the tabs at the cell terminals and the circuit is de-energised."

Easy to do in theory, not so easy in the real world. The way the packs are assembled, taped and glued together you simply can't access those points in the circuit without pulling the cells apart and opening things up far enough to get a wire cutter "in there". Thats partially how I made the two mistakes listed above... trying to shove my wire cutter in between and beneath tight areas to access the points to disconnect the cells.

I get the packs from the recycle program at work.... one mans trash...:o

The intent of my posting is not to discourage the idea of modding / replacing / salvaging ells, but more to alert CPFers who do take on such a project. There are safety concerns and an element of risk in doing this. The video dismissed the safety concerns all together and made it look no more dangerous than reloading AAs into a VCR remote. Furthermore, the pack used for the demo is unusually well laid out, with cells perfectly side by side.... very low risk of + and - contacts being close to each other. I took apart a toshiba pack just like that, for its 17670 cells and it was relatively easy.

Excellent post! :thumbsup:

 

[LuxLuthor]

Hmm. Maybe there is? :thinking:

Edit: there is in fact a "report" link. I'm going to report this and hope the MEtaCafe people care enough about safety to take it down.

Edit 2: the "report" link does nothing for me, I keep clicking it but no way of reporting the video actually comes out. :/

I reported it, but the choices of why you are reporting don't list "dangerous."

Only choices that are close are:

• "Video is offensive" :)
• "Not suitable for under 18" :duh2:
• "Video violates terms and conditions" :confused:
• "Video is pornographic or obscene" :party: (my favorite)
  

 

[Fallingwater]

There's got to be something in their terms of use that forbids videos that could get other people to injure themselves...

 

[nmos]

So if I've got a pack with just a few bad cells it's ok to just replace the bad ones? Do the replacements have to have the same capacity? I assume I have to replace any that are in parallel with the bad one(s) at the same time. I just opened up a pack for my Thinkpad A22 to see what cells were in it but the cost to buy all 9 cells is surprisingly close to just buying a replacement pack.

 

[Fallingwater]

So if I've got a pack with just a few bad cells it's ok to just replace the bad ones?

No. It's important that all cells have the same capacity, so as to prevent reversal. Even if you use cells of the same capacity, you'd be putting brand new ones in series with old ones that have inevitably lost capacity due to use and age.
Either replace them all or don't replace anything.

Do the replacements have to have the same capacity?

Not necessarily, if you're swapping all of them. Using better cells will give you improved runtimes, though the battery gauge might be set to the old capacity and go haywire.

I assume I have to replace any that are in parallel with the bad one(s) at the same time.

Actually no, the parallel configuration is safe for different capacities as long as you connect them when they have the same resting voltage (or bad things can happen). But you do need to replace any in the series, and that means the whole pack.