What Is The Average Lifespan Of A Watch Battery?

Every watch battery has a finite lifespan and inevitably reaches a point when it no longer provides sufficient power to support the reliable functioning of the timepiece. So, how long do most watch batteries last?

The average lifespan of a watch battery is roughly two to five years. However, watch battery lifespans vary significantly depending on the watch type, battery materials, and battery storage conditions. Complex timepieces like chronographs use more battery power than basic digital LCD watches.

Battery-powered watches (also called button cells) lose their utility when their power source expires. Consequently, replacing watch batteries on time is crucial (pun intended). If you’re wondering how long watch batteries generally last, let’s take a closer look at the topic of watch battery longevity.

How Long Does The Average Watch Battery Last?

The lifespans of watch batteries vary considerably. While the average watch battery lasts between two to five years, some last as short as a year, and others provide power for up to ten years.

Numerous variables influence the lifespans of watch batteries. The size of a watch battery is central to its longevity. These batteries range in diameter from 4.8mm to 11.6mm. As one might expect, larger watch batteries (sometimes called coin batteries) store more power than smaller batteries because the former have greater power capacity.

Watch battery materials play a decisive role in determining the longevity of these power sources.

The quality of the manufacturing process is another fundamental variable that influences watch battery lifespans. Poorly-manufactured watch batteries generally won’t last more than 12 months. Some high-quality watch batteries made for premium watch brands have significantly longer lifespans of five to ten years.

Battery life also depends on the kind of watch and its power requirements. Watches with multiple functions use more battery power than simple watches that only keep and display the time.

Storage is another critical but easily overlooked variable that determines how long watch batteries last. Exposure to moisture or extreme temperature fluctuations in warehouses (or during transportation) may potentially compromise the lifespan of watch batteries.

Watch Batteries: Types, Materials, And Lifespans

Watch batteries provide power to watches by transforming chemical energy into electricity.

Batteries for powering watches have a metal casing (usually stainless steel), which holds two sections called the anode (negative) and cathode (positive). The anode and cathode contain a gel-like mix of metal electrodes and chemicals (electrolytes).

The two most common types of watch batteries are:

lithium,
silver.

These batteries are named after the materials that their electrodes are composed of. Aside from their materials, the primary distinctions between lithium and silver batteries are their power capacity and lifespans. Here is a brief description of the basic characteristics of these ubiquitous watch batteries.

Lithium Batteries

Lithium watch batteries (or coin batteries) have anodes made from lithium (and manganese oxide cathodes). The batteries contain an electrolyte composed of lithium perchlorate (a highly soluble form of lithium) that is dissolved in an organic solvent of dimethoxyethane and propylene carbonate.

Lithium watch batteries are large and provide high amounts of power. The average power output (nominal voltage) of lithium batteries is 3.00 volts (V). When these batteries near their expiration point (end voltage), they generate a 2.00V charge.

Due to the materials they’re made from, lithium batteries cost less than other kinds of batteries.

Another advantage of lithium batteries is that they do not leak harmful chemicals. However, there is a risk that lithium batteries might explode when exposed to extreme heat. The intensity of their electrical charge also means that lithium batteries drain rapidly when watch circuitry malfunctions.

Silver Batteries

Silver watch batteries have silver oxide cathodes (and zinc anodes). These button batteries are smaller and provide less power than lithium versions. The nominal voltage of most silver batteries is 1.55V, while their end voltage is 1.20V.

Silver watch batteries are available in low-drain and high-drain versions. Low-drain silver batteries contain sodium hydroxide electrolytes and carry less power than high-drain versions. High-drain silver batteries have electrolytes composed of potassium hydroxide.

Silver batteries are inexpensive, but they cost more than those made with lithium (because silver is not cheap). Another disadvantage of silver batteries is their tendency to leak when improperly stored or handled (a consequence of having highly reactive zinc anodes and alkaline electrolytes).

Watch Battery Shelf Lives And Lifespans

Silver and lithium watch batteries have different shelf lives. Shelf-life refers to the anticipated time batteries remain operational while in storage (and not in service).

Batteries have a finite shelf life because they undergo slow and subtle chemical reactions over time, regardless of the storage conditions. As a result of these inevitable chemical reactions, watch batteries lose roughly between 5 and 20% of their initial charge every 12 months.

Lithium batteries have shelf lives of 10 years, while the shelf-life of silver batteries is about 5 years.

The shelf lives of watch batteries correspond to their operational lifespans, which means lithium batteries are typically the longest-lasting batteries available on the market.

Indeed, the average lifespan of lithium batteries is 5 to 7 years (though some may last as long as 10 years). In comparison, silver watch batteries generally last between 3 and 5 years. Both battery types provide consistent levels of power while in service but experience a substantial drop in their capacity as they approach the end of their lives.

The following table summarizes the central characteristics of silver and lithium batteries.

Battery Type	Cathode	Anode	Electrolyte	Lifespan	Relative Cost	Power Capacity
Lithium	Manganese oxide	Lithium	Lithium salt (lithium dissolved in organic solvent)	5 to 7 years (up to 10 years)	Less expensive than silver batteries	High Nominal voltage of 3.00V
Silver	Silver oxide	Zinc	Potassium hydroxide (high-drain batteries) Sodium hydroxide (low-drain batteries)	3 to 5 years	More expensive than lithium batteries	Low Nominal voltage of 1.55V

Watch Types And Battery Consumption

Watch battery lifespans are heavily determined by the type of timepiece being powered.

Watches that perform multiple functions consume more power than simpler watches that only keep and display the time. For instance, there is a considerable difference between the battery power requirements of chronograph and digital display watches.

Digital Chronograph Watches

Digital chronographs are multi-functional watches that require high levels of battery power. These complex and reliable watches are associated with

In addition to displaying the time (with hour, minute, and second hands), digital chronograph watches also serve as mechanical stopwatches.

Most of these timepieces have specialized features such as telemeters (for distance measurements) and tachymeters (for speed calculations). Some chronograph watches have as many as five batteries, each with different capacities and lifespans!

Chronograph watches consume considerable amounts of electrical power to support their diverse array of functions. The lifespan of the digital chronograph watch batteries is 10 to 12 months (depending on the type of battery) if the stopwatch and other features are activated constantly.

Turning the chronograph function and additional features off when these capabilities are not in use will extend battery lifespans to approximately two years.

Digital Display Watches

Digital display watches are basic electronic timepieces that use less power than chronographs. Unlike chronograph timepieces, these watches are regulated by quartz crystals and have liquid crystal displays (LCDs).

Digital watches perform a limited number of simple functions. In most instances, these devices show the time and date and have simple, additional features like digital stopwatches and calculators.

In addition, digital watches don’t contain moving mechanical parts (in contrast to chronograph watches).

Due to the elementary features and lack of moving parts, digital display watches require minimal battery power.

Consequently, the average lifespan of digital watch batteries ranges from 2 to 6 years.

As a result of their minimal power requirements, digital display watches are also usually powered by silver batteries (rather than lithium batteries).

Battery Consumption Of Old And New Watches

A watch’s age is another crucial factor that influences how long batteries last.

The general rule is that watches use more battery power as they get older because the efficiency of the devices decreases over time. Consequently, batteries might not last as long as expected when they’re powering a poorly-maintained antique timepiece.

In contrast, batteries last dramatically longer when watches are new (or maintained diligently).

Watch Power Consumption VS Battery Capacity

We can calculate the expected longevity of watch batteries based on the ratio between electrical power consumption and battery capacity (measured in milliamps per hour or mAh).

The formula for calculating a watch battery’s anticipated lifespan is as follows:

(battery capacity x 1000) / watch power consumption = battery lifespan.

Let’s apply this formula to a 20mAh battery in a digital LCD watch (which only consumes about 1 microamp per hour):

20mAh x 1000 / 1microamp = 20 000 hours.

So, the anticipated lifespan of a 20mAh battery in a digital display watch is 20 000 hours or about 26 months.

How To Tell When A Watch Battery Needs Replacing

As watch batteries approach the end of their lifespans, they need replacing because they start to lose power. It is also vital to replace watch batteries regularly because the risk of harmful leaks increases as batteries age. Fortunately, it is easy to tell when it is time to replace a watch battery.

The most obvious and unmistakable sign that a battery has expired is that the watch hands and dials have stopped moving.

Another sign that a watch battery needs replacing is when the second hand is spinning too fast.

In the case digital LCD watches, a blank screen provides conclusive evidence that the battery has expired. A dim or blurred screen indicates that the battery is nearing its expiration and needs to make way for a fresh one.

Some watches have inbuilt battery-life indicators that make it super simple to know how much longer a watch battery will last.

FAQs About Watch Batteries

Here are the answers to some frequently asked questions about watch batteries.

How Much Does A Watch Battery Cost?

The average price for a watch battery is $10 to $12.

However, watch battery prices vary considerably depending on the manufacturer, materials, and size.

For example, batteries for luxury or high-tech watches cost upwards of $20 to $30 (and more).

Is There Mercury In Watch Batteries?

In the US, mercury is used exclusively in button cell batteries due to its toxicity. Silver and lithium batteries contain minuscule amounts of mercury. However, the Environmental Protection Agency categorizes these batteries as safe because of the low probability that the mercury might leak.

Mercury batteries (containing a mercury oxide cathode) were taken off the market in many countries during the 1990s.

Can I Replace My Watch Battery Myself?

In most cases, it is quick and easy to replace a watch battery yourself. Most watches have screws or slot fixtures at the back that are easy to remove and allow access to their expired or broken batteries. Other watches have a backplate that snaps off and on so you can replace their battery.

There is small risk of damaging your watch when you replace its battery, so it is crucial to working cautiously and gently when opening the watch, removing the old battery, and inserting its replacement. A pro-tip for replacing watch batteries is to use a pair of tweezers!

While it’s usually possible to replace watch batteries at home, there are a few exceptions. For instance, if you need to replace an old battery in a delicate, luxury-brand watch, it is advisable to procure the services of a professional.

Is A Watch Still Waterproof After Battery Change?

When changing a battery in a waterproof watch, there is a risk of compromising the seal that keeps water from entering and causing damage to the interior of the timepiece.

After waterproof watches have their batteries replaced, it is advisable to have the timepiece re-sealed and pressure-tested by a professional horologist. This additional time and cost will prevent water from degrading or destroying the watches.

Conclusion

Watch batteries usually last between 2 to 5 years before they need replacing. Having said this, the average lifespan of some batteries is longer than others. Lithium batteries last 5 to 7 years. In contrast, silver batteries generally last 3 to 5 years.

The average lifespans of watch batteries vary according to many factors. These factors include the type of timepieces the batteries are powering. A battery’s lifespan is shorter when powering watches with mechanical hands and multiple complex functions (such as chronograph watches). The same battery is likely to last longer in simple digital display watches.

What Is The Average Lifespan Of A Watch Battery?

How Long Does The Average Watch Battery Last?