# LI Battery connection

Thread Starter

#### beatsal

Joined Jan 21, 2018
218
I have a coin battery LI/MnO2 for a small flashlight which is almost dead, want to replace it. Thought it would be a simple solder but looks like more i.e. there is a thin strip connected to it but not soldered, looks like a spot weld to me. How to replace this battery?

#### SamR

Joined Mar 19, 2019
3,409
I've had some success soldering wires to batteries by first roughing the battery end cap with an emery board or bit of sandpaper. Most are shiny and with a bit sanding they take on a matte/scratched surface appearance. Cleaned with 99% Isopropyl alcohol to remove any oils, flux, and solder. Yes, most are spot welded at the factory.

Thread Starter

#### beatsal

Joined Jan 21, 2018
218
Thanks. First I have to remove the connection, not sure how.

#### SamR

Joined Mar 19, 2019
3,409

#### MisterBill2

Joined Jan 23, 2018
8,761
Soldering to a battery will usually damage the seals and lead to a much shorter battery life.

#### anniel747

Joined Oct 18, 2020
1,063
Soldering to a battery will usually damage the seals and lead to a much shorter battery life.
And must be done rapidly with a good clean tip.

#### MisterBill2

Joined Jan 23, 2018
8,761

#### anniel747

Joined Oct 18, 2020
1,063
Solder tabs will almost always pull right off of a battery. That has been my experience.And then I have clamped them onto the replacement battery and not soldered anything.
You can also use an appropriate cell holder.

#### KeithWalker

Joined Jul 10, 2017
1,785
Soldering to a battery will usually damage the seals and lead to a much shorter battery life.
I never had that problem. The secret is to use a large enough iron, a good flux and as little time as possible.

#### KeepItSimpleStupid

Joined Mar 4, 2014
4,761
Solder tabs will almost always pull right off of a battery. That has been my experience.
Poor quality batteries?

I buy about 20 CR2032's at a time. The website appears to be offline, but it was like 20 CR2032 for $20.00 USD or so postage paid. Postage eats into the cost. I can also buy them from somewhere else and have them shipped to a sattelite office and pay no pastage. #### anniel747 Joined Oct 18, 2020 1,063 Poor quality batteries? I buy about 20 CR2032's at a time. The website appears to be offline, but it was like 20 CR2032 for$20.00 USD or so postage paid. Postage eats into the cost. I can also buy them from somewhere else and have them shipped to a sattelite office and pay no pastage.
They cost less on Digi_Key for reputable brands in that quantity.

#### anniel747

Joined Oct 18, 2020
1,063
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