X220 Battery Recelling

[N4b00]

hi guys, i'm trying to search online how can i recelling my x220 battery, someone know where i can find some howtos or info to do that?

Thanks

N4b00

[Qing Dao]

I'm interested in this as well. I have read about it being difficult for X230 batteries, but for X220 batteries, I have no idea.

[N4b00]

I'm interested in this as well. I have read about it being difficult for X230 batteries, but for X220 batteries, I have no idea.

Hi, why it should be difficult to recelling x230 battery?

[astral]

There's CHANS Battery in Canada who can likely do it (chansbattery.ca), but that's for Canada and the US if you're willing to pay the shipping. Likely would be prohibitively expensive from overseas. I'm sure there's GOT to be a place in China that can do it though, with how much of the electronics manufacturing industry is located there and all. Just don't know one.

And to answer the question on WHY it's difficult to recell these batteries - it's the BMS. The vast majority of laptop BMS chips are designed to "shut down" or otherwise break themselves (some via a fuse of some kind) when they detect that the cell chain has been broken. They're designed to prevent recelling, likely to sell more batteries, with perhaps some safety reasons sprinkled in there.

[axur-delmeria]

There was another thread somewhere in this forum that discusses battery re-celling.

One of the things I learned there is that there's a 3-pin fuse that the BMS can blow that prevents the lithium cells from getting any power. Replacing that fuse (if it's already blown) is one of the steps to rebuild a battery pack.
The other part is to reprogram the BMS firmware and reset the data. I think most of the problems lie here.

The long and short of it is that it's easier to rebuild a pack as long as it holds a charge. Then the hard part becomes "how to attach the new cells without removing the old ones first" because the BMS will definitely blow that fuse if it reads zero volts (if the old cells are simply disconnected).

[N4b00]

thanks for replies, but i've tried some aftermarket batteries and i hadn't positive experiences so i would like to rebuilt battery by myself. I think that a peoples that recell batteries (like chansbattery) for a large of number of device doesn't rebuilt bms or firmware from scratch..... I've seen, on internet, a guy that create an opensource battery for t420...

[samveen]

- I've tried to disassemble a battery previously, but it came apart as a broken mess, definitely not something that could be put together again.
- Anyone have a dead x220 battery that they would be able to disassemble using the process shown in https://www.youtube.com/watch?v=LSWTM6jePEY which shows better results than mine
- There seems to be a lot of detail about recelling in this forum post: https://forum.thinkpads.com/viewtopic.php?t=121516
- Hackaday project that does the same https://hackaday.io/project/245-replaci ... -batteries
- Back in 2020, I have seen a blog by a Chinese thinkpad owner where he demonstrated how to connect the 18650 cells together, AFTER balance charging them using his own homebrewed charging system, such that the BMS curcuit always had current in it, and therefor didn't trip any fuse. However I cannot find any bookmark to that blog page, nor am I able to get it via search. EDIT: Found it: https://www.yousun.org/archives/1572

[kfzhu1229]

Over the past month or so I have been on a marathon of rebuilding my laptop batteries, after finding a neat seller locally that sells cheap gently used 3500mah LG 18650 MJ1 3500mah cells along with spot welding services for minimally extra, and I have some bare but brand new sanyo 3500mah 18650GA cells too from last time begging to be used.
So far I've rebuilt 5 Acer OEM battery packs (a few of which are my "lab rats" to try my first attempts on and they end up working), one HP OEM battery pack and a Dell aftermarket battery pack with success, and probably my next up business would be rebuilding a T530 9 cell battery pack.

- Have the battery pack spot welded. If that's absolutely impossible at the very least have some new thin nickel strips and have it soldered flush up against the cell (this takes a lot of practice). Try not to reuse welding strips as the mangled ones can be tricky to solder flush (and give you problems with fit later).
- If you don't have a programmer (I don't), you have to do it with "live" BMS, and this doesn't just mean connecting the positive and negative terminals to a power source at all times, you MUST connect the middle pins too (1 for 2 in series packs, 2 for 3S packs and 3 for 4S packs). Learnt this the hard way by hooking just the terminals of an Acer pack with a 9V battery and I see the fuse blown by the BMS seconds after desoldering the middle pins.
- Remember to unstick the temperature probe (s) first before you touch anything else - this is very easy to forget and will give you heap of trouble if you snap it instead.
- If you're new to this, try to work on something "easier" and if you can afford some extra cells, try to start with a "labrat" battery you don't care as much about if you destroy the BMS. a simple rectangle shaped 2S2P 4 cell or 3S2P 6 cell configuration is much easier to work with than a 4S1P 4 cell or a 9 cell or one of those oddly shaped 6 cells like the Acer Aspire 5742 battery I worked on. This is why I worked on that tricky 4S1P battery for the highly collectible Acer Iconia 6120 dual screen tablet last, after garnering all the experiences I needed (and also that battery is practically unobtanium on the internet if I break it).
- Lastly, you won't exactly get full 3500mah rating of the cells in the case of those I am using. First, in the case of those 2 cells, if you assume a 2A discharge the effective capacity is ~3300mah. Then also the cut off voltage threshold of your laptop BMS is probably way higher than what the cell can take (in the case of those packs, 3.2V vs 2.5V per cell). From my computation that effectively lands you with a capacity of ~2800-2900mah. Still miles better than any aftermarket pack you'll ever find and better than even NOS ones too.

So here's so far of what I've been doing:
1. Examine the battery pack, take as much time as you need to think about the possible options you can exercise to swap the battery packs with a live BMS and think it through, take a lot of photos and examine the pictures closely. Don't rush through it. Measure the voltages of all the cells in case the charge is imbalanced. Preferbly make both the new and old pack partially discharged with about 3.3-3.6V per cell, this way it will be much less gnarly if you accidentally short something.
2. Take the assembled replacement pack and try to make it match the connection locations as the original pack. Put insulating materials wherever the original pack used them. If a nickel strip connection comes out of the negative of the cell and wraps to the body, you can get away with no insulation. If it loops via the positive end of the cell to the negative body of the cell, isolation is mandatory, preferably at least 2 layers. If in doubt, insulate.
3. There are these ways I can use to make the secondary connection always live: connect a jumper wire to the old pack or to the new pack (all of them), or if the connection is a nickel strip I can solder the new pack with a wire directly to the strip, and then snip the strip to disconnect the old pack when it's all said and done. Establish the secondary connections, gently wiggle it to make sure it's secure. For the primary connection that will stay, you can get away with weaker wires for the middle connections, but use at least 22awg solid core copper wire for the terminals (or even better, use direct nickel strip connection)
4. put the new pack either on top or on the bottom, and start transferring the connections one by one. Take your time one by one, think it through, do not rush!
5. When the transfer is done, carefully fit it back into the shell. Do it bit by bit, put extra insulation material when necessary. If a nickel strip wiring is supposed to be up against the battery cell body, make sure it stays that way and not smashed flat up against the BMS board! Take a clear picture when you fitted it all the way back in, zoom in to examine any potential hazards that need addressing (and have this picture so that you have reassurance later on that this battery pack is safe).
6. IF your laptop battery bay is fully unpainted plastic, you can get away with testing the battery pack without full reassembly.

Gallery: https://1drv.ms/f/s!AuILfFUnTy5cjXKSLsV2tE594UVQ
(If you can't tell, my replacement cells are either the LG 18650 MJ1 dark green cells or the Sanyo 18650GA red cells with no visible labelling to the camera because it's impression printed on the sleeve)

[samveen]

As and when you get to any of the Thinkpad batteries, can I request you to document the opening of the battery pack, if you manage to do it non-destructively?

I can try and give you pics of the the 44+ that I opened, destructively, if you think that'll help with opening the battery packs.

[kfzhu1229]

As and when you get to any of the Thinkpad batteries, can I request you to document the opening of the battery pack, if you manage to do it non-destructively?

Unfortunately I don't have a sure fire way to open these up without destruction. I just simply find the best suitable opening point, twisting and bending the shell might help some, and then just wedge some screwdrivers there and go slowly. I am just lucky that Acer batteries almost never truly stand in your way when it comes to rebuilds. Their BMS will for sure screw you if you disconnect power, but beyond that they aren't made to be evil.
I have almost no luck with aftermarket battery packs though, those plastics are generally poorly made and also instead of clips many just use loads of epoxy to hold them together and there's no way you can pry those open without destruction.
Additionally, I found that aftermarket BMS tend to be much less evil, or in many cases, you can completely disconnect power and reconnect it and it'll work just fine. Unfortunately though they tend to have thin thru hole cable wiring at odd places which somewhat hinders the safety of the battery pack, and that if you replace the cells with good name brand cells, aftermarket BMS' typical cutoff voltage threshold is way too high (10.2V vs say 9.6V for a typical 10.8/11.1V pack) for you to get the full potential of the cells, and that also they many times have trouble decreasing wear count.

[kfzhu1229]

As and when you get to any of the Thinkpad batteries, can I request you to document the opening of the battery pack, if you manage to do it non-destructively?

I can try and give you pics of the the 44+ that I opened, destructively, if you think that'll help with opening the battery packs.

So I still havent worked on those kinds of thinkpad batteries yet, BUT I did just work on an HP OEM 8 cell battery pack today, that is heavily glued down rather than clipped down! I believe I found the solution to heavily glued down batteries which I assume is the problem you have with x220 battery.
And the solution is... slicing with a crafting or surgery knife blade!
First, try to figure out how the crevices work on the glued down edges, i.e. figure out which way you should be slicing. Then, try to pick a weak spot, preferably in the long edge facing inside the battery bay, and then use the very sharp and thin knife blade mentioned before, preferbly with a proper handle to let you use force on, insert it into the crevice, try to make it an entry point. On a very well glued down battery pack like my HP one, it took 4 tries to have a successful entry point.
Once your blade successfully entered into the crevice, use a very small flathead screw driver to keep the entry point pried open. Slice across the sides to cut away that epoxy/superglue, work on it nice and slow. It is possible your blade either slides off or end up cracking the edge plastic and need to restart the slicing.
Once the long edge is done, you should then be able to pry it open with a bigger flathead pretty easily and non-destructively. Repeat for the other sides if necessary.
You can see if that specific hot swap example will help you in your case as well.
Overall, I am just super happy this still worked out despite the challenge with the casing - this battery was very hard to get! Practically all the original 8 cell batteries for these 15 and 17 inch HP Compaqs are dead and the only reason this one lived is because it's from 2010 - as a result of battery recall with Sony cells, hence very uncommon and I had to buy a whole laptop just to get this!
Here's an album for this special procedure: https://imgur.com/a/0KUSgQk
Good luck