Index / Shell 26.5 x 17.5 x 48.5 mm / 6LR61

6LR61

6LR61 — alkaline, 9 V, 26.5 x 17.5 x 48.5 mm, known as a 9V cell. Current. 6LF22 takes the same slot at the same 9 V; 6F22 drops straight in, and runs the same 9 V, and it is carbon zinc, which holds far less; 7.2H5 drops straight in, and runs 7.2 V — -20.0%, which reads low, and it is rechargeable, never a drop-in.

What fits the compartment, and what does not

Fit answers whether it enters the compartment. Voltage answers whether the circuit will notice. A cell that fits is not always a safe substitute.

3 cells drop in and they are not equivalent: of those, 7.2H5 sits furthest at -20.0% of this cell’s 9 V, low enough that a calibrated instrument reads below true.

Also stamped 1604A, 522, 522 ALKALINE POWER, A522V, EN22, X22, EP522

Same size, and not the same voltage

The 9V compartment takes cells of more than one voltage. This one is 9 V; AC146X in the same size runs 8.4 V, -6.7% of this cell — low enough that a calibrated instrument reads below true. Nothing about the shape warns you, which is why the label matters more here than the size does.

What the chemistry changes

Everything above answers size and voltage. What it cannot answer is chemistry, and 3 other kinds are in play here beside the alkaline this cell uses.

• Alkaline drops in voltage steadily as it empties, so a device calibrated for a flat discharge will drift as it goes.
• Carbon zinc carries a fraction of the capacity of an alkaline cell of the same size and leaks more readily when spent.
• Nickel-metal hydride is rechargeable and sits at 7.2 V, below the nominal of the primary cell whose slot it takes. It is never a drop-in for a primary cell no matter how well it fits, and a device that cuts off early will read it as flat.
• Lithium runs at 9 V, roughly six times the nominal of the alkaline and silver classes. Of the 26 lithium cells here whose envelope the maker publishes, 3 share that envelope with an alkaline or silver cell.

What a smoke alarm needs from a cell this size

In a United States home the commonest thing behind a 9 V cell is a smoke alarm, and an alarm is the one device that has to warn you before it stops. Energizer publishes 565 mAh for 6LR61.

6F22 carries the same 9 V in the same shape and is published at 330 mAh, 58% of this cell. Same compartment, a fraction of the run. 7.2H5 fits the same clip and is rechargeable at 7.2 V. Its voltage falls off a cliff instead of drifting down, so the low-battery chirp an alarm is tuned to may never arrive. The nearest is 6F22: it drops straight in and runs 9 V, same volts.

• Alarm manufacturers name an acceptable cell on the unit and in the manual. Where a device is a safety device, that name settles it and this table does not.
• 4 cells measure close enough to compare against it in the Energizer data this site reads, and 4 of them are still listed.
• By stored energy it stands 1 of 2 in its envelope, at 5085 milliwatt-hours.
• Energizer files it for Asia Pacific, Europe, Latin America and North America, which is where the part is sold rather than where the cell will work.

Drawn to scale

Every published figure

12 figures are published, and one is not: impedance. The row is absent rather than estimated. It reaches shelves as 522, 522 Alkaline Power, A522V and EN22.

2 rows in the table are not the maker's but ours: stored energy and energy per cubic centimeter. Everything else is reproduced without change.

What the maker says about cold

The sheet for 6LR61 carries an operating range as well as a capacity, and it reaches -18 C (-0 F) at the cold end. 4 more published figures follow it, and none of them reaches a cross-reference table.

The part occupies 21 cubic centimeters and weighs 45 g. Capacity and voltage together put 5085 milliwatt-hours in that space. Energizer files it for Asia Pacific, Europe and Latin America.

Operating range

-18 C (-0 F) to 55 C (131 F). Below the lower figure the maker makes no claim at all, which is not the same as the cell stopping.

Cutoff voltage

0.8 V. The published capacity is counted down to this voltage; a device that quits higher up sees less than the whole figure.

Maker's classification

Alkaline. That is the maker's own filing word for the part, not a standard designation.

Mass against volume

45 g filling 21 cubic centimeters. When the printing has worn off, a kitchen scale separates two cells of one envelope faster than a caliper does.

Where the part is filed

Asia Pacific, Europe, Latin America and North America. That is a statement about the maker's distribution and not about where the cell works.

Is that a lot of energy?

Nothing else measured in this shell holds more. At 5085 milliwatt-hours it leads 1 other cell, and the next one down carries 21% of what it does. Per unit of volume that is 242 mWh per cubic centimeter, denser than 29% of everything measured here.

A width the catalog keeps returning to

not published mm is a width this catalog keeps coming back to: 0 boxes sit within half a millimeter of it, 6LR61 included.

Its 242 milliwatt-hours per cubic centimeter sit above 29 percent of everything here that publishes both a capacity and a volume. 8 of the 50 boxes share its 9 V exactly.

• 6F22 — the next step down by volume: 20.3 cubic centimeters against this cell's 21.
• 1604LC — the next step up: 21.4 cubic centimeters, 102% of this one.

The maker's own part numbers

6LR61 carries 7 names beyond the designation, and every one of them is a manufacturer part number: a catalog line, not a size and not a standard.

• 1604A — a manufacturer part number for 6LR61, not a standard designation.
• 522 — a manufacturer part number for 6LR61, not a standard designation.
• 522 ALKALINE POWER — a manufacturer part number for 6LR61, not a standard designation.
• The maker's own catalog carries 6 product lines under it.

The identical cell with different insides

Nothing about the outside of 6LR61 separates it from 7.2H5: the same 26.5 x 17.5 x 48.5 mm, and 7.2 V against this cell's 9 V. The label is the whole difference.

It stands 1 of 2 in this envelope by stored energy. On a scale the difference shows before it shows on a caliper: this one weighs 45 g.

• 7.2H5 — the same 26.5 x 17.5 x 48.5 mm in nickel-metal hydride at 7.2 V. Identical on a caliper, different in the circuit.
• 7.2H5 — sold as the same 9V and rated 7.2 V against this cell's 9 V.

One figure the maker does not publish

One field is empty for 6LR61: impedance. A blank means the maker publishes no figure, which is not the same as zero, and it is the reason one comparison below is missing rather than wrong.

The blanks are the same in all 6 records behind this designation, so they are the catalog's silence and not a merge losing a value. What is not missing is the envelope: 26.5 x 17.5 x 48.5 mm, published and checked against the designation itself.

• No impedance — so this page cannot tell you whether the cell can drive a pulse, which is the whole question in a watch or a sensor.

Before you swap anything

Everything here is computed from published dimensions and nominal voltages. That answers whether a cell enters the compartment and whether the voltage matches on paper. It does not answer what your device does with the difference, and it cannot: a cell that fits can still be the wrong cell.

One more limit, and it is the biggest. This site reads a single manufacturer’s catalog. When a page says a designation is not listed, that means Energizer no longer offers a part under it — not that nobody makes the cell. Other makers may still sell it, and for common sizes they usually do.

A voltage difference is one relation between two cells, and this page prints it from the cell it is about — in every table on the page, including the one listing cells no longer made. A figure always belongs to the cell whose voltage is printed beside it: a cell that runs lower than this one carries a minus here, one that runs higher carries a plus, and two cells at the same nominal voltage carry zero. Meet the same pair on the other cell’s page and the sign is the other one, with the figure taken against that cell instead of this one; where the two run at the same voltage, both pages print zero. The class beside the figure is not read off that figure directly. It is decided on the gap itself, taken against the higher of the two nominal voltages, so one pair of cells gets one class whichever page you meet it on: counted from this side the boundary of the class that still runs falls at 20.0% below and 25.0% above, which is the same gap divided once by the larger nominal and once by the smaller. What genuinely differs between the two directions is the consequence, and the words carry it: a cell that runs low makes a calibrated instrument read below true, and a cell that runs high makes it read above.

3 things this site cannot see. Whether the contacts reach a shorter cell. Whether the device was calibrated for a chemistry that holds its voltage flat, which silver oxide does and alkaline does not. Whether the equipment tolerates the higher current a different chemistry can deliver. Rechargeable cells are never a drop-in for primary cells regardless of size.

Cells measured next to this one

The shell is shared across chemistries: 2 cells sit at exactly this size in alkaline and nickel-metal hydride. Same hole, different insides, different discharge curve.

• 7.2H5 — 26.5 x 17.5 x 48.5 mm, 7.2 V
• 6LF22 — 26.5 x 17.5 x 48.5 mm, 9 V

Where these numbers come from

Dimensions, voltages, chemistries and capacities are published by the manufacturer and reproduced without change. Everything else on the page is ours, computed from those figures: whether one cell fits where another sat, how far apart their voltages are, stored energy and energy per cubic centimeter, the rank within a shell, and the check of the designation against the measured size.

Fit is decided within 0.3 mm on every axis, which is the order of a contact spring's travel. Voltage classes are decided by consequence, not by roundness, and they are decided on the gap between two nominal voltages taken against the higher of the two: 2.0% or less of it is the same working voltage, 6.0% starts to matter to a calibrated instrument, and past 20.0% it is a different class altogether. Measuring the gap against the higher figure is what makes the verdict the same from either cell’s page, while the printed percentage stays counted from the cell you are reading about. Cells with identical stored energy share a rank instead of being ordered arbitrarily.

Ranking uses capacity times nominal voltage, because capacity alone is not comparable across chemistries: 150 mAh at 3 V is twice the energy of 150 mAh at 1.5 V. Neighbors are chosen by measurement and never alphabetically, because two cells filed next to each other by name usually have nothing in common. A blank in any table means the maker publishes no figure, which is not the same as zero.

Source: Energizer technical data, retrieved 1 September 2026.

Records that disagree behind this page

6LR61 is assembled from 6 catalog records, and they do not agree with each other on every field. Both sides are numbered below so the disagreement can be read rather than taken on trust.

1. [1] Energizer catalog record 171, listed as 522, active in the snapshot. Technical data sheet: 522.pdf.
2. [2] Energizer catalog record 270, listed as EN22, active in the snapshot. Technical data sheet: en22-industrial-na0920.pdf.
3. [3] Energizer catalog record 705, listed as A522V, obsolete in the snapshot. Technical data sheet: a522v.pdf.
4. [4] Energizer catalog record 955, listed as X22, obsolete in the snapshot. Technical data sheet: x22.pdf.
5. [5] Energizer catalog record 1230, listed as EP522, active in the snapshot. Technical data sheet: ep522.pdf.
6. [6] Energizer catalog record 2517, listed as 522 Alkaline Power, active in the snapshot. Technical data sheet: 522_alkaline_power_gl.pdf.

Every figure above is reproduced from those records without change; the comparisons are ours and are described on the method page. Snapshot: Energizer technical data, retrieved 1 September 2026.

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