Soldering Wires to a CR2032

[bostonman]

I have a Dell laptop and the 2032 battery seems to be dying because periodically the time changes.

I discovered it's not a standard 2032, but one with wires soldered to it, wrapped in a seal, and a connector on the other end. Rather than buy a replacement for $10 (found them on Ebay), I'm thinking I can solder wires to an existing 2032.

A YouTube video suggested using silver bearing rosin solder. I also read that the battery case can be sanded (which I assume exposes the underlying metal that regular solder will solder to).

Does anyone know which method works best?

[aqibi2000]

Just solder to it done it several times. Keep scratching at the surface  and it will solder

[wraper]

I'm thinking I can solder wires to an existing 2032.

Please don't do that. You will damage the battery and there is even a chance it will explode. If you want to make your own, you need to buy a battery with welded on terminals then solder to those terminals.

[james_s]

Soldering to batteries is generally a really bad idea, the proper way to attach wires is to use a capacitive discharge spot welder, I built one years ago specifically for this purpose. You can also buy BR-1632 (and other sizes) which are the same as CR-xxxx cells but with tabs already welded to them.

Keep in mind as well that there are also rechargeable Li-ion cells which look very much like standard CR types, do verify that your laptop is not expecting one of these, many/most are.

[wraper]

You can also buy BR-1632 (and other sizes) which are the same as CR-xxxx cells but with tabs already welded to them.

"BR" prefix does not have anything to do with terminals. It's battery with different chemistry and slightly lower capacity for the same size. But they are more temperature stable and have less self discharge. Also BR-1632 has lower thickness diameter/capacity than 2032. You can buy both CR/BR without or with terminals.

[james_s]

Hm yeah I guess you're right, I'm not sure why I had that in my head.

At any rate you can buy the cells with or without tabs, and the point of verifying exactly what sort of cell you've got there stands.

[JFJ]

... I'm thinking I can solder wires to an existing 2032.

To avoid possible damage from overheating, it would be better to solder the wires to a button cell holder, and then insert your existing CR2032.

[AVGresponding]

You can also buy BR-1632 (and other sizes) which are the same as CR-xxxx cells but with tabs already welded to them.

"BR" prefix does not have anything to do with terminals. It's battery with different chemistry and slightly lower capacity for the same size. But they are more temperature stable and have less self discharge. Also BR-1632 has lower thickness/capacity than 2032. You can buy both CR/BR without or with terminals.

The first half of the number denotes the diameter, not the thickness, which is denoted by the second half of the number.
A 1632 is 16mm diameter, 3.2mm thick, a 2032 is 20mm diameter, 3.2mm thick

[wraper]

A 1632 is 16mm diameter, 3.2mm thick, a 2032 is 20mm diameter, 3.2mm thick[/color][/b]

You are right, I wrote it wrong even though I knew which digits meant diameter and which thickness..

[senso]

2 for 1€, if the connector polarity is wrong, just swap the wires in the connector, and this one has long leads so most likely it will fit in any laptop.
https://www.ebay.com/itm/2pcs-DC08-Dell-G4221-Latitude-D610-D620-CMOS-RTC-BIOS-3V-CR2032-Battery-2-PinSMN/352908058620?

[bd139]

When I was a kid we used to collect all the old button cells and go round a friend's house and fry them on his dad's camping stove. You do not want to be around when the buggers blow up. They are like little pipe bombs.

[Nusa]

Have you checked the voltage on your existing battery to confirm that it actually is out of spec before replacing it?

[bostonman]

Have you checked the voltage on your existing battery to confirm that it actually is out of spec before replacing it?

It's a good question, and the answer is no. I didn't want to remove the battery and lose date/time; and I assumed this would be an easier thing to do.

The plastic sealer around the battery reads 2032, but has a few other letters - I've since screwed the cover on again, so I don't know what the number is but can look later. It also had, what I assume to be, a date code, which read the year June or July 2010.

I know the battery hasn't been replaced since the laptop was purchased, and, since the time seems to change periodically, I figured for the $1 battery, I'd replace it; until I discovered it's not easy because it's "sealed".

[Monkeh]

It's not 'sealed', it has leads attached. They're readily available to just plug in for pennies..

[james_s]

Have you checked the voltage on your existing battery to confirm that it actually is out of spec before replacing it?

It's a good question, and the answer is no. I didn't want to remove the battery and lose date/time; and I assumed this would be an easier thing to do.

The plastic sealer around the battery reads 2032, but has a few other letters - I've since screwed the cover on again, so I don't know what the number is but can look later. It also had, what I assume to be, a date code, which read the year June or July 2010.

I know the battery hasn't been replaced since the laptop was purchased, and, since the time seems to change periodically, I figured for the $1 battery, I'd replace it; until I discovered it's not easy because it's "sealed".

Why are you worried about the date and time being lost? It takes about 30 seconds to set that.

Make sure you've got the right sort of battery to replace it, verify that yours is non-rechargeable before you replace it with one. You can probably buy one for a few dollars that is shrinkwrapped already with the proper connector on it, otherwise get one with solder tabs welded on it and solder the existing wires to those.

[Mazo]

I have soldered a small TH diode's leg to a CR2025.As I wanted to keep heating to minimum the procedure I used is the following.
1.Apply flux to the spot on battery you will solder to.
2.Make a blob of solder on a flat soldering iron tip.
3.Put whatever you are soldering on the flux spot and press firmly with the solder blob for a second maximum.

By the way after the intervention I measured the battery's open circuit voltage and when it was still hot it dropped significantly(I remember figures around 2V) and recovered to around 80% of the value it had just before soldering,so I guess it got some damage!

All in all if if you aren't in a hurry I think there are smarter ways to skin this cat.

[bob91343]

I am surprised that nobody has mentioned the (to me) obvious solution, which has worked for me.  You buy a 2032 holder.  Put the cell in it and you have solderable pins.  Replacement is easy.  They only cost a few cents on ebay.  Search 2032 holder.

[wraper]

You buy a 2032 holder.  Put the cell in it and you have solderable pins.  Replacement is easy.  They only cost a few cents on ebay.  Search 2032 holder.

And then it won't fit because it's too big. It's not like there are heaps of free space inside a laptop.

[Muttley Snickers]

You buy a 2032 holder.  Put the cell in it and you have solderable pins.  Replacement is easy.  They only cost a few cents on ebay.  Search 2032 holder.

And then it won't fit because it's too big. It's not like there are heaps of free space inside a laptop.

I'm not sure about space in the latest or more recent laptops but I did exactly this in an old Gateway laptop which I still use for field work. The original battery was located under the keyboard and difficult to access so I stuck a battery holder in the front section where the speakers are and it's now much easier to replace.

[johnkenyon]

I'm thinking I can solder wires to an existing 2032.

Please don't do that. You will damage the battery and there is even a chance it will explode. If you want to make your own, you need to buy a battery with welded on terminals then solder to those terminals.

Last time I looked at cpc.farnell.com a single CR2032 with solder tabs was cheaper than a single battery without tabs.
The only reason I didn't use the tabbed version was because I wanted to use a battery holder (MK48T02 battery replacement).

Back to the original post - I'd recommend going with the tagged battery, recycling the existing battery lead then covering it with heat shrink - worked for me with an old Dell Inspiron laptop last year.

[mattgaidica]

Don't solder to the battery. Get some copper tape (https://www.adafruit.com/product/1128), solder to it, stick it on.

[oliver602]

I soldered two 2032 cells for a auto darkening welders helmet. I tried to do it as quick as possible but the second one exploded. It sounded like a gun shot and my ears were ringing. Luckily it didn't hit me in an eye. Left quite a lot of black powder in all corners of the room.

Wouldn't recommend

[Monkeh]

Don't solder to the battery. Get some copper tape (https://www.adafruit.com/product/1128), solder to it, stick it on.

Why? Just buy one with tabs or even better, buy one with pre-attached leads and a plug. They're readily available.

[CharlotteSwiss]

some time ago soldered the cable directly on the cr2032 battery of an old multimeter. After reading this treadh I think you know it went well ...

[BrokenYugo]

Mouser/Digikey/etc. sell tabbed and probably even leaded 2032s of reputable manufacture (I like Panasonic) for surprisingly cheap prices. False economy to mess with soldering to the battery or eBay/amazon crap.