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iam4722202468 / ThinkpadBattery

Open source Thinkpad T420 battery design
MIT License
258 stars 23 forks source link

PLEASE MAKE FOR LENOVO X220 #14

Open jakevin99 opened 2 years ago

jakevin99 commented 2 years ago

I am planning to recell my 9 cell x220 battery but problem is the chip inside.

iam4722202468 commented 2 years ago

This will probably work on the x220 without any changes

Michal-Szczepaniak commented 1 year ago

But will it work on **30 models?

iam4722202468 commented 1 year ago

But will it work on **30 models?

Nah, unmodified the **30 models use a signature packet between the battery and laptop to ensure the battery is authentic. No way around this, as messages cannot be signed without having the key. There is this project which you can use to remove the signing and make the battery work.

Michal-Szczepaniak commented 1 year ago

What if i have corebooted **30 model? Then it will work?

iam4722202468 commented 1 year ago

Coreboot itself is only a modification for the bios. The EC (Embedded Controller) is what communicates with the battery, and is what needs to be modified.

Michal-Szczepaniak commented 1 year ago

gotcha

Bromiun commented 1 year ago

Isn't there a practical way to get around this problem? A pack is usually 3S2P. And let's say you have 6x 18650s to replace.

Charge the pack and 6 good cells to full. Solder (with wires) 3S of the good cells to the existing two power strips and two balance strips in the pack. This will keep the handshake trap happy.

Remove 3S of the bad cells. Replace with good cells. Either soldered or spot welded.

Remove the 2nd set of 3S bad cells and replace with the first 3S of good cells.

I believe that it is sufficient for one cell to go bad, to make the battery pack useless. So test the 6 bad cells and you may find a few still operational.

iam4722202468 commented 1 year ago

That is possible, but it requires having a working battery. The goal of this project is to create a working battery from scratch.

Bromiun commented 1 year ago

Yes, a valid point. During my 15 years having multiple ThinkPads, I have accumulated a lot of packs with bad cells. Buying packs off eBay is a possibility and my last purchase I believe about $50 is fantastic. I used to open the packs up and replace the cells straight. I soon discovered that is a good way to kill a pack.

At one time, the laptop male connector got misaligned, and due to a defect in the design, when you push in the battery, it even clicks giving you a false sense that connection has been made. I could not get any pack to work and there was no mention of this issue in any forum. I went through 3 or 4 packs till I discovered the problem and simply aligned the male connector and it has been working to this day.. So I have a few working packs. The design problem is that the female connector on the pack is spring loaded. So it does not have to mate with the male terminal to insert the pack, and you can still push it in and force a false positive click.

I am sure you can find cheap packs that have bad cells but are still alive. Have you tried this?