Looking for a CMOS battery for Lenovo X1 tablet gen 3

[babblefish]

Sounds simple enough, except everywhere I go they sell a CR1620 battery with the wrong connector on the end. The connector on their batteries is about four times bigger than the one from my tablet. Their connector is about 3mm wide at the point where it plugs in. The battery from mine is about 2.2mm wide.
Anyone know where I can get a CR1620 battery with the correct size connector?

[axur-delmeria]

On my X61, I went as far as ripping out the spot-welded tabs on my old CMOS battery, then secured them to a bare CR2025 cell using heatshrink tubing.

In your case, you can just splice the wire from your old CMOS battery to the new one.

[babblefish]

Thanks. I ended up doing something like that. I ripped the tabs off the old CR1620 CMOS battery with the wires and connector still attached to them, then spot welded them onto a CR2016 battery I had laying around. I then wrapped the battery in Kapton tape to insulate it from the metal bits inside the tablet. The CR2016 is close to the same thickness, but a litter bigger in diameter. Luckily, it fit in the battery space. I'd still like to be able to get a new battery though because the one I put in is a little weak at 2.8V. Worse comes worse I'll just buy a new CR2016 and spot weld the wire/connector onto that. I imagine Lenovo would be more than happy to sell me one of their OEM batteries for $50.

BTW, I build battery packs for RC models, scooters and ebikes, so that's why I have a small spot welder for working on metal battery tabs. Beats trying to solder wires onto a lithium battery and having said battery blow up in my face.

[dcfbf]

You can switch the polarity on the battery connectors. https://www.youtube.com/watch?v=PaxzYtSDF4E
No need for spot welding

[babblefish]

You can switch the polarity on the battery connectors. https://www.youtube.com/watch?v=PaxzYtSDF4E
No need for spot welding

I'm not trying to switch polarity. I'm trying to get the correct electrical connector on the battery so it will plug into the tablet. The connectors on the batteries vendors are selling for the X1 tablet, gen 3 is the wrong type of connector and is also too big. Many of the vendors are blurring out the connector in their ad pictures so they must know it's wrong but want to sell it to unsuspecting people anyway. Plus many are CR2016 or CR2032 cells, which is doubly wrong.

[dcfbf]

you can also swap the connectors this way. Just take the connector from the dead battery and put it on the new battery

[RealBlackStuff]

@dcfbf:
did you actually READ what OP has done?

[dcfbf]

Yes I have read.
Actually, you know what, I'll record a video of me swapping connectors.

https://drive.google.com/drive/u/0/fold ... D97GlozFtV
As you can see, I to swapped a fat connector from a dead battery onto a good cmos battery with originally a slim connector.

Unless I misunderstood OP's post entirely that it wasn't a matter of these connectors, I think this is a perfectly fine solution to the issue.

[RealBlackStuff]

Swapping connectors is only part of the problem
(and could have been done easier/faster with just a small pin or paperclip).
A bare CMOS battery costs about $3.
That same battery with cables and a connector costs probably $10 or more.
More work if you also need to swap the (possibly wrong) connector.
Easiest/cheapest solution: remove the contacts from the old CMOS and attach them to the new CMOS with Kapton tape or shrink tubing.
Nice to have (like OP): a spotwelder for such CMOS batteries.

[dcfbf]

Ehhh, yeah you're right, you can do that.

But ???????? How did you get that a cmos battery with cables costs $10?
Since you are trying to swap the connectors anyway, it doesn't matter what you buy, just buy the cheapest one with cables and a connector.
You can get a pack of 10 for under 6 dollars.
I just looked online and it seems that's the going rate for a bare coin cell as well.

I think it's about the same amount of work to rip off and wrap vs swapping connectors.

[RealBlackStuff]

The only time I see (bare) CMOS is in the supermarket.
To be honest, I haven't looked online for prices in many years, as I still have many used Lenovo ones lying about.
They used to be rather expensive from what I remember...

[babblefish]

Yes I have read.
Actually, you know what, I'll record a video of me swapping connectors.

https://drive.google.com/drive/u/0/fold ... D97GlozFtV
As you can see, I to swapped a fat connector from a dead battery onto a good cmos battery with originally a slim connector.

Unless I misunderstood OP's post entirely that it wasn't a matter of these connectors, I think this is a perfectly fine solution to the issue.

‐‐-----------------------‐‐-----------------
Yes, I know how to do that. But, the connector on my tablet's CMOS battery is about half the size of the smaller one in your video.

None of the prewired X1 Tablet batteries offered for sale on eBay, Amazon, or anywhere else has the correct sized connector. Plus, the prices range from US$12 to US$60 for each battery. I've seen a couple of vendors selling ten prewired batteries for US$12, but the battery size is wrong, the connector is wrong, but most important of all, at that price I wouldn't trust them to keep my wall clock running. I don't trust anything that's too cheap to be true. The old saying applies here, you get what you pay for.

All that being said, since I have ten laptops/tablets, six being Thinkpads, I prepared a couple of coin batteries of two different sizes for CMOS duty by spot welding solder tabs to them and electrical insulation. I'll just transfer the wires/connector over from the dead one when the time comes. The bare coin cells are cheap, so why not. And no, I don't buy the cheapest batteries.

[dcfbf]

Ah I see, I apologize then.
I was not aware of how elusive and expensive the X1 Tablet's cmos batteries actually were and how small they were.
I personally would buy the cheapest battery available, but I completely understand that buying a trusted battery with cables already soldered onto them would cost more and therefore wouldn't be worth it.

The main point of my original reply was to present a solution that didn't need spot welding because I can't spot weld.
I didn't and I still do not know how an X1 Tablet 3rd gen's cmos battery connector looks like (because I do not have one), but I can imagine, from what you have described, swapping connectors in the way I demonstrated would be nearly impossible. (I already struggle with the small size of the smaller size connector I showed in my video)

It seems the best method then for someone who can't spot weld is using the method brought forward by RBS which is

Easiest/cheapest solution: remove the contacts from the old CMOS and attach them to the new CMOS with Kapton tape or shrink tubing.