ThinkPad T2x battery pack rebuild - anyone?

[kfzhu1229]

The story is I have a lot of 9 cell T4x batteries, because I use T43p as my main laptop. One of them apparently doesn't perform good enough for me to abuse it anymore, so I decided to disassemble the battery pack and put 6 of the 9 cells into a T22 battery which lasts 5 seconds. The result is that it worked for a day or so, and then the controller fried because it had so many expanded capacitors. The controller refuses to transfer electricity both ways so I could neither charge nor discharge. So now what I am doing is actually wiring up the positive terminal of the battery to the positive pin of the battery directly as well as passing through the board. Now the battery works without any percentage estimates. So now I have 3 issues:
1. the computer shuts down without further notice as expected.
2. since the controller reads as 0%, I couldn't boot without AC power (error 190) and had to boot to windows before I unplug the power as otherwise the computer would go to sleep and wouldn't wake up.
3. Do I run into a risk of overcharging the battery and blow up my house?
Also do any of you have those battery/circuit boards lying around and close to Toronto Canada?

P.S: One thing I learnt in this the hard way is to always try to insulate as good as possible. I was being lazy and instead of soldering the wires inside the soldering hole, I was too lazy to clean the solder and soldered them on top of the holes. Then problems don't appear until I assembled the casing and put it into my laptop - the pressure of the case made the wires go after each other and almost caught fire!

[Thinkpad4by3]

The story is I have a lot of 9 cell T4x batteries, because I use T43p as my main laptop. One of them apparently doesn't perform good enough for me to abuse it anymore, so I decided to disassemble the battery pack and put 6 of the 9 cells into a T22 battery which lasts 5 seconds. The result is that it worked for a day or so, and then the controller fried because it had so many expanded capacitors. The controller refuses to transfer electricity both ways so I could neither charge nor discharge. So now what I am doing is actually wiring up the positive terminal of the battery to the positive pin of the battery directly as well as passing through the board. Now the battery works without any percentage estimates. So now I have 3 issues:
1. the computer shuts down without further notice as expected.
2. since the controller reads as 0%, I couldn't boot without AC power (error 190) and had to boot to windows before I unplug the power as otherwise the computer would go to sleep and wouldn't wake up.
3. Do I run into a risk of overcharging the battery and blow up my house?
Also do any of you have those battery/circuit boards lying around and close to Toronto Canada?

P.S: One thing I learnt in this the hard way is to always try to insulate as good as possible. I was being lazy and instead of soldering the wires inside the soldering hole, I was too lazy to clean the solder and soldered them on top of the holes. Then problems don't appear until I assembled the casing and put it into my laptop - the pressure of the case made the wires go after each other and almost caught fire!

Yea, what your doing is what they did in the NiCD days, the only difference is that NiCD reverse charged gets slightly warm and loses its capacity(I accidentally reverse charged for 16 hours on brand new battery ) and Li-ion will blow its head, with your house along with it. If one cell gets overcharged because the balancer isn't balancing the batteries or warning the computer when one of the cells gets too high.

This is what happens when Li-Po cells go wrong. Li-ion are in a protective metal shield which will slightly reduce the problem but still the danger is there.

https://www.youtube.com/watch?v=-DcpANRFrI4#t=41

If I didn't scare you yet than nothing will.

What you did is make the world largest Galaxy Note 7, a unsafe battery just waiting to explode.

[ac12]

Depends on what battery you use.

I would NOT use a Lithium battery, because you NEED to have controlled charging. Li batteries are not to be fooled with, they can get nasty.

NiMH might be OK.
The problem is, where is the charging circuit? If it is in the battery case, then you are out of luck, cuz you could easily overcharge the NiMH battery. As I recall unmanaged charging is at C/10, for no more than 16 hours. But that is for an EMPTY (fully discharged) battery. The problem is with a partially charged battery, a 16 hour charge could overcharge the battery.

Replacement batteries are available on eBay for about $20.
IMHO, it is not worth the hassle and danger of tinkering with the battery.

If you cannot start the computer without AC power, why even bother with a battery? Just use the computer w/o a battery.