Index / Shells

Find a cell — type the code stamped on it, or its size in millimeters

Suggestions as you type need scripts. Without them this box still goes to the code index, which needs none.

Shells

An envelope is a diameter and a height, and it is what decides whether a cell enters the compartment at all. 9 envelopes here carry 3 designations or more, which is where substitution questions start. 4 of them are coins, the flat shape of a watch battery or a button battery.

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

What the table shows when you read down it

Across the 9 envelopes here the data holds 34 designations, and 8 of them are no longer listed by the maker — 23.5 of the whole. That share is the reason this site exists: the code stamped on a cell in a drawer is more likely to be a name the catalog has dropped than a name it still sells.

11.6 x 4.2 mm spans the most chemistries: 4 kinds different kinds share that one name, which means a compartment marked with it will physically close on cells that behave differently in the circuit.

14.5 x 50.5 mm holds the widest voltage spread of any envelope here, 0.3 V between its lowest and its highest. Nothing about the holder warns which one the device was designed around, and no figure on this site can tell you what the device does with the difference — only what the difference is.

Every figure above is computed from the snapshot named at the foot of this page, not copied from a table anywhere. Where the maker publishes nothing for a designation, it is counted in the totals and left out of the averages rather than filled in with a guess.

Every envelope in one line

The table above answers one row at a time. The question people actually arrive with is comparative — whether the name on their cell covers one voltage or a range, and how wide the range is. Here is each envelope as a single line, with the figures that decide a substitution rather than the figures that describe a catalog.

envelope

A range in that list is a warning, not a detail. Where a name covers more than one voltage, the holder closes on all of them and nothing in the device says which it expects; where it covers more than one height, the taller one may hold the lid open. Both are answered on the page for that

11.6 x 4.2 mm — 5 designations, 2 still listed, 1.4–1.55 V, 4.2 mm tall.

14.5 x 50.5 mm — 5 designations, 5 still listed, 1.2–1.5 V, 50.5 mm tall.

10.5 x 44.5 mm — 4 designations, 4 still listed, 1.2–1.5 V, 44.5 mm tall.

7.9 x 3.6 mm — 4 designations, 2 still listed, 1.4–1.55 V, 3.6 mm tall.

7.9 x 5.4 mm — 4 designations, 2 still listed, 1.4–1.55 V, 5.4 mm tall.

68.2 x 68.2 x 115 mm — 3 designations, 2 still listed, 6 V, 115 mm tall.

11.6 x 5.4 mm — 3 designations, 3 still listed, 1.45–1.55 V, 5.4 mm tall.

26.2 x 50 mm — 3 designations, 3 still listed, 1.2–1.5 V, 50 mm tall.

34.2 x 61.5 mm — 3 designations, 3 still listed, 1.2–1.5 V, 61.5 mm tall.

, cell by cell, with the drawing at real scale.

Why this list is shorter than the data

The snapshot holds 159 envelopes in all; 9 of them are shown above. A shell earns a page here when at least 3 designations share it, because below that there is nothing to compare: a page that lists one cell and calls it a group answers a question nobody asked. The 150 envelopes left out are not missing from the site — every designation in them has its own page or its own row in the code index, which carries all of them with no threshold at all.

The threshold is a property of this list, not of the world. A cell whose envelope is shared by nobody else is still a real cell, and the fact that nothing else is made in its shape is itself the answer to a substitution question: there is no drop-in, and the search box will say so by size.

If the printing has worn off, measure it

A cell whose face has rubbed smooth still carries a width and a height that cannot rub off. The search box on every page of this site takes them directly — type 11.6 x 4.2 and it answers with LR43, or type 11.6 alone and get every envelope that wide. That is the same index the code search uses, read by size instead of by name.

Measure across the flat face, not across the crimp: on a cylindrical cell the crimped rim is the widest point and it is not the figure the maker publishes. Measure the height with the cell standing on the flat, positive face up. A caliper is better than a ruler here for one reason: this site treats anything inside 0.3 mm as a drop-in, and a ruler cannot tell 4.2 mm from 3.6 mm — which are different cells.

The measurement is worth taking even when the code is readable. Of the 9 envelopes listed here 4 hold coin cells, where a fraction of a millimeter of extra thickness is the difference between a lid that closes and one that does not, and the tallest envelope in this table stands 115 mm. A code tells you what the maker called it; the caliper tells you what is in your hand.

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.

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.