Energizer 379 Coin Cell Silver Oxide Battery

The 379 is a silver oxide coin cell, and it is sold here the way it is used: one cell at a time. Silver oxide is the chemistry that watch and instrument makers reach for, because it holds its nominal 1.55V almost flat across its working life rather than sagging steadily as it drains. The cell is a plain metal-cased button, and the wide face carries the 379 code, the Energizer name and a + symbol, so you can confirm both the code and the polarity with the cell out of the device and in your hand.

Coin cells in this size sit in small, shallow battery compartments, the sort found in quartz watches, slimline calculators, key fobs and compact measuring instruments. The number on the face is the thing to match: if the cell you are replacing reads 379, this is its like-for-like equivalent. Where an old cell has worn its markings away, read the code printed inside the battery door rather than judging by eye, because several coin cells share a similar diameter while differing in thickness and in voltage, and a close-looking substitute can either foul the compartment or run the circuit at the wrong level.

The case is the whole of the construction: the wide flat face marked with the + is the positive terminal, the opposite face is negative, and there is nothing to unwrap or prepare before fitting. One point is worth being clear about before you order. This listing is priced and sold per cell, so one unit is one 379 cell rather than a box of ten. The minimum order is ten, which means cells are bought in multiples of ten, and that suits anyone servicing several watches at once or keeping a few spares in a workshop drawer alongside the other sizes they use.

How many cells do I actually receive?

This listing is priced and sold per cell, so one unit is a single 379 cell. The minimum order is ten, so cells are bought in multiples of ten and you receive ten individual cells on a minimum order.

What voltage does a 379 cell give?

The nominal voltage is 1.55V, which is a property of the silver oxide chemistry rather than something printed on this cell. Silver oxide holds close to that figure for most of its working life instead of tailing off gradually.

How do I know a 379 is the right cell for my watch?

Match the code. If the cell you removed reads 379, or the number is printed inside the battery door, this is the equivalent. Coin cells of similar diameter can differ in thickness and voltage, so guessing by size alone is unreliable.

What is the difference between silver oxide and alkaline button cells?

Alkaline button cells are nominally 1.5V and their voltage falls away steadily as they discharge. Silver oxide sits at 1.55V and stays near that level, which is why timekeeping and measuring devices tend to specify it.

Which way round does the cell fit?

The wide flat face carrying the 379 marking and the + symbol is the positive terminal, and the opposite face is negative. Fit the marked face against the contact your device marks with a plus sign.

Is a coin cell the same thing as a button cell?

In everyday UK use the two names are interchangeable for this shape of battery, a flat metal disc a few millimetres thick. The supplier calls it a coin cell and you will also see it listed as a button cell.