Guide · updated 10 November 2026

C and D battery voltage: what a good cell reads on a multimeter

C and D cells are 1.5 V alkaline cells, like AA and AAA cells, only larger. A new one reads about 1.60 V on a multimeter. The larger size holds more charge. It does not change the voltage, so one chart covers both sizes.

iPhone and iPad (iOS 17 or later): free on the App Store. Android later.

The chart: C and D alkaline at rest

C / D alkaline: voltage at rest
Verdict	Voltage at rest	What it means	What to do
FULL	1.55 V and up	As good as new.	Ready for use.
GOOD	1.45 to 1.55 V	Plenty left.	Ready for use.
WEAK	1.30 to 1.45 V	Most of the charge is used.	Fine for clocks and remotes. Swap it soon in anything that draws more.
REPLACE	under 1.30 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.

How to measure a C or D cell

Take the cell out of the device and wait a minute.
Set the multimeter to DC volts. On a meter without auto-range, pick the 2 V range.
Touch the red probe to the end with the raised cap (plus) and the black probe to the flat end (minus).
Hold the probes still until the digits settle, and read the voltage with two decimals.
Look it up in the chart.

Test the cells one by one

A flashlight or a radio runs its C or D cells in series, so the weakest cell sets the limit. Measure each cell on its own:

All cells in the same band: the set is as good as that band says.
One cell far below the others: that cell stops the device. Replace the whole set, not only the low cell, so that old and new cells are not mixed.

At rest and under load

The chart is for a cell at rest. A device measures the cell while it works, and big C and D cells often feed motors and lamps that draw a lot of current. A worn cell can read GOOD at rest and still sag under such a load. If the cells read GOOD and the lamp is dim, try a fresh set before you blame the lamp.

Rechargeable C and D cells

A rechargeable NiMH cell follows the NiMH scale, not this one: it is a 1.2 V cell and reads lower than an alkaline cell when it is perfectly healthy. See NiMH rechargeable battery voltage.

The 6 V lantern battery

A 6 V lantern battery is four such cells in series in one block, so its scale is four times the scale of one cell, rounded. It has two spring terminals: if the meter shows a minus sign, swap the probes.

6 V lantern: voltage at rest indicative
Verdict	Voltage at rest	What it means	What to do
FULL	6.20 V and up	As good as new.	Ready for use.
GOOD	5.80 to 6.20 V	Plenty left.	Ready for use.
WEAK	5.20 to 5.80 V	Most of the charge is used.	Fine for clocks and remotes. Swap it soon in anything that draws more.
REPLACE	under 5.20 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 one tile for C and D cells and one for the 6 V lantern battery. Pick the tile, touch the probes to the battery, and the app shows FULL, GOOD, WEAK or REPLACE with the next step. "Test another" keeps the same battery type, so you can work through a set of cells quickly. 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. One tap saves each reading with a label and a note.

Where the numbers come from

The bands come from the alkaline handbook of a battery maker (Energizer) and common battery testers. They are the bands the app uses. The lantern battery's bands are our own estimate from four cells in series, so they are marked indicative. 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
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

At what voltage is a 1.5V battery useless?

For an alkaline cell at rest, under 1.30 V: it is empty for most devices. Between 1.30 and 1.45 V it is WEAK and still fine for a clock or a remote control.

What should a D battery read on a multimeter?

A new alkaline D cell reads about 1.60 V. It is FULL from 1.55 V and GOOD from 1.45 V. A C cell reads the same.

Is a D battery the same voltage as an AA?

Yes. Alkaline AAA, AA, C and D cells are all 1.5 V cells with the same voltage chart. The larger cell holds more charge and can deliver more current, so it lasts longer.

Try it in the demo

A simulation of the app in your browser, with made-up readings: no meter and no install needed.

Try the battery tester in the demo Coming

Get TestNMeasure for iPhone and iPad.