How to test a lithium coin battery

[Nayov]

I have a device which takes a lithium coin battery which has been acting erratically for at least a year. Back then, I tested the battery which showed 3V, which is the correct amount so I assumed the circuit board was cracked and just lived with it the best I could. Well, last week on a lark I put in a new battery and it works like brand new; old one still tested good at 3V though.

Is it possible for the voltage on a lithium batt to read at spec but be bad, kind of like cold cranking amps on a flooded car battery not able to start a car in at cold temps but still have 12V?

 

[Lubener]

You are statically testing the battery unloaded. Put a load on it and it likely will fall below 3v if you have time to kill. Me, I would just toss the battery and appreciate a successful diagnosis with your three dollar battery replacement..
BTW- a car battery measuring 12v unloaded is considered dead. Measuring a battery unloaded is not an accurate way to determine its condition.

 

[MasterSolenoid]

When using my multimeter to check voltage, there are two locations to turn the dial to.
Location one is, 'just plain' voltage.
Location two is for checking batteries, it puts a slight drain on the battery while checking.
But my meter only checks batteries that are 1.5 and 9 volts.

Preventive maintenance: Good idea to change batteries in garage-door openers and ignition key fob regularly.

 

[Randol]

I'd go pull the data sheet for your P/N.
You need to apply a load and monitor the voltage.
See an example below, A quick test would be the pulse drain in the lower right of the page.

https://data.energizer.com/pdfs/cr2016.pdf

 

[Lubener]

When these 3v batteries are in question, just replace it. They are under three dollars and not worth spending time splitting hairs over.

 

[y_p_w]

I've tested assorted batteries open cell and in a device under load. The voltage under load can drop like a rock. For instance, I had this TV set and even new alkaline would drop to well below the voltage I'd see with good NiMH batteries. But they would last about as long because the alkaline had about twice the theoretical capacity.

That being said, I remember a drug store I went to had a tester for batteries including button and coin cells. It literally said to poke the probes through the packaging. I know if I saw a battery that had been punched through the packaging, I wouldn't even think of buying it.

 

[Nayov]

OK, so testing underload is the key, I gather. The irony is that I bought a blister pack of 12 off brand batteries about 8 or 9 years ago for $1.50 from the bargain table at Ace Hardware and one of those cheap and long outdated batteries fixed my issue. Contacts were clean incase anyone was wondering.

 

[paulo57509]

I picked up one of these on ebay. It will test batteries under load.

It has a slot on the side under the brown button for button batteries; slip the battery in and press the button to test. The (-) contact is handy for can cells.

 

[wrcsixeight]

I go through this every so often with my dad.

The 3v lithium battery still reads over 3v and he declares it still good but device does not work. Replace cell and it does.

Ive measured some coin cells new out of packaging as high as 3.68v, and some as low as 3.21v, and some devices still worked 'just fine' with a coin cell measuring 2.73v.

I try and stuff a thicker cell into to any device which lets me.