Guide · updated 10 November 2026
CR2032 voltage: how to test a coin cell with a multimeter
A new CR2032 reads about 3.25 V on a multimeter, and it stays close to 3.00 V for most of its life. That flat voltage makes a coin cell easy to measure and hard to judge: a cell near its end can still read almost like new. This page has the chart, the right way to probe a coin cell, and the check under load that finds the cells a resting reading misses.
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The chart: CR2032, CR2025, CR2016 and CR2450 at rest
| Verdict | Voltage at rest | What it means | What to do |
|---|---|---|---|
| FULL | 3.15 V and up | As good as new. | Ready for use. |
| GOOD | 3.00 to 3.15 V | Plenty left. | Ready for use. |
| WEAK | 2.80 to 3.00 V | Most of the charge is used. | Fine for clocks and remotes. Swap it soon in anything that draws more. |
| REPLACE | under 2.80 V | Empty for most devices. | Replace it, and recycle the old one. |
Measured at rest, with nothing connected. A reading exactly on a boundary counts as the higher band.
The four cells share one scale, because they share one chemistry: lithium manganese dioxide. The number is the size. A CR2032 is 20 mm across and 3.2 mm thick, a CR2025 is 2.5 mm thick, a CR2016 is 1.6 mm thick, and a CR2450 is 24.5 mm across and 5.0 mm thick. A thinner cell holds less charge. Its voltage is the same.
Which face is plus
On a coin cell the wide flat face, the one with the writing, is plus. It wraps around the edge of the cell. Minus is the smaller face on the other side.
- Take the cell out of the device. Hold it by its edge, so your fingers do not bridge the two faces.
- Set the multimeter to DC volts. On a meter without auto-range, pick the 20 V range.
- Touch the red probe to the wide face with the writing and the black probe to the smaller face. Lay the cell on a table that does not conduct: do not hold it between two metal tools.
- Hold the probes still until the digits settle, and read the voltage with two decimals.
Why a coin cell that reads fine can still fail
A lithium coin cell holds about 3.00 V until it is nearly empty, and then drops. The devices it powers, such as a car key, a tracker or a sensor, draw their current in short pulses. A used cell cannot hold its voltage during such a pulse, even when it still rests at 2.80 V or more. So:
- Under 2.80 V at rest: replace it. That reading is clear.
- 2.80 to 3.00 V at rest: WEAK. In a device that sends radio signals, replace it.
- Above 3.00 V at rest and the device still complains: check the cell under load.
A check under load
A datasheet tests a CR2032 with a pulse: a 400 Ω load for 2 seconds, and the cell counts as empty when it falls to 2.0 V. You can do a gentler version with any multimeter and one resistor:
- Measure the cell at rest and note the voltage.
- Hold a 1 kΩ resistor across the two faces. It draws about 3 mA.
- With the resistor in place, measure the voltage across the cell after about 2 seconds, then remove the resistor.
A good cell hardly moves. As a rule of thumb, a cell that falls under about 2.7 V with the resistor connected is weak, and one under 2.5 V is used up. These two values are indicative: they come from practice, not from a datasheet.
LR44 and SR44 button cells
LR44 and SR44 have the same size and different chemistries. LR44 is alkaline and falls steadily. SR44 is silver oxide: it stays very flat at about 1.55 V until the end, so a reading under 1.48 V means it is nearly finished. The SR44 bands are indicative.
| Verdict | LR44 alkaline button | SR44 silver oxide indicative |
|---|---|---|
| FULL | 1.55 and up | 1.57 and up |
| GOOD | 1.45 to 1.55 | 1.53 to 1.57 |
| WEAK | 1.35 to 1.45 | 1.48 to 1.53 |
| Below Weak | under 1.35REPLACE | under 1.48REPLACE |
Measured at rest, with nothing connected. A reading exactly on a boundary counts as the higher band. Indicative: few sources or a flat curve, so treat these bands as a guide.
Hearing-aid cells
Zinc-air hearing-aid cells need air to work. Pull off the tab and wait 2 minutes before you measure: a sealed cell reads low. They hold about 1.4 V until they are nearly empty, so the chart has only two verdicts. Sizes 10, 13, 312 and 675 share it.
| Verdict | Voltage at rest | What it means | What to do |
|---|---|---|---|
| OK | 1.35 V and up | Still working. | Ready for use. |
| REPLACE | under 1.35 V | Empty for most devices. | Replace it, and recycle the old one. |
Measured at rest, with nothing connected. A reading exactly on a boundary counts as the higher band. Indicative: few sources or a flat curve, so treat these bands as a guide.
The shortcut in the app
Coming Coming in an app update. It is not in the app you can install today.
The battery tester in TestNMeasure has tiles for CR2032, CR2025, CR2016, CR2450, LR44, SR44 and hearing-aid cells. Pick the tile, touch the probes to the cell, and the app shows the verdict with the next step. It measures at rest, like the chart on this page, so the check under load stays a job for a resistor. More: Battery tester.
The app you can install today already shows the meter's reading large on your phone, with five stability bars that light when the reading is steady. That helps with a coin cell, where both hands are busy with the probes. One tap saves the reading with a label and a note.
Where the numbers come from
The resting bands come from a battery maker's CR2032 datasheet (Energizer), a coin-cell maker's guidance (Renata) and a Texas Instruments note on coin cells under pulse load. They are the bands the app uses. You can also type a reading into the battery checker, or start from the general guide: how to test a battery with a multimeter.
What the app does here, and what it doesn't
| What it does | Plan |
|---|---|
| Pick the battery type and see FULL, GOOD, WEAK or the end of its life from the DC volts, with the next step. | Free Coming |
| A large readout that shows which digits have settled; OL and UL are shown as OL and UL, never as a number. | Free |
| Five stability bars show when a reading is steady. | Free |
| One tap saves the current reading, with an Undo. | Free |
| Add a text note and a short label to any capture. | Free |
Not yet, or not planned
- No load test: the battery tester reads the voltage without load, so it cannot show a car battery's cranking strength.
- Reads what your meter measures; it doesn't change the meter's accuracy or ranges.
Questions
What voltage should a CR2032 read?
About 3.25 V when new, at rest. From 3.15 V it is FULL and from 3.00 V it is GOOD. It does not read 3.6 V: that value belongs to other lithium chemistries, not to a CR cell.
At what voltage is a 3V battery dead?
At rest, a lithium coin cell under 2.80 V is used up: replace it. Under load, datasheets count 2.0 V as the end. The two values differ because a resting cell reads higher than a working one, which is why you find anything from 2.0 to 2.7 V quoted.
How to tell if a CR2032 battery is good?
Measure it at rest: from 3.00 V it is GOOD. If the device still reports a low battery, repeat the measurement with a 1 kΩ resistor across the cell. A good cell hardly drops, a used one falls clearly.
Are all 2032 batteries 3 volts?
All CR2032 cells are. CR stands for lithium manganese dioxide, a 3 V chemistry, and 2032 is the size. Cells of the same size with other letters can have another voltage: a rechargeable LIR2032 is a Li-ion cell at about 3.6 V. Read the letters, then pick the chart.
Try it in the demo
A simulation of the app in your browser, with made-up readings: no meter and no install needed.
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