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Do Watches Need Energy to Work? A Look at Their Insides

July 16, 2021

You don’t have to be a watch collector like myself to admit that watches are engineering wonders. But how do they work? Do watches need energy to work? The answer is yes. My article looks at each energy type and the science behind how different timepiece movements utilize them. Let’s get started.

Kinetic Energy

Kinetic energy is produced by objects in motion. There are two types of watches that use it. They are automatic and kinetic pieces.

Automatic watches

You will move your arms several times a day – they produce kinetic energy. Timepieces with automatic movements use energy to wind their mainsprings, which would in turn move their gears. The gears ultimately move their watch hands.

You’re not going to wear your watch all the time. That’s why you might be wondering whether automatic watches stop working when they come off your wrist.

When you take them off, the amount of time it takes for the mainsprings to run out of energy is dictated by their power reserves. Most of the time, this would be 40 hours. But more expensive watches can go beyond this. Once the time is up, you’ll have to manually wind the springs. You’ll have to use the crowns on the devices to wind them again. 

Unfortunately, the time told by automatic watches is not very accurate. The accuracy would be around /+ 25 seconds a day.

Kinetic Watches

Kinetic watches are relatively new. They came on the scene in the late 1980s thanks to Seiko. They’re also called automatic-quartz units.

The energy your body produces is used to move pendulums. The pendulums move pinions. The pinions move at high-speed – almost 100,000 rpm. As they move, generators produce currents that charge capacitors.

How does the energy from the capacitors get their mechanisms running? This is where the quartz part of the “automatic-quartz” name comes from. The capacitors cause quartz crystals to vibrate, which creates pulses that move the watch hands. I’ve talked about quartz mechanisms in-depth below.

How long it would take for the capacitor to run out of juice depends on the watch model you own. Most of the time, this is between 2 weeks and 6 months.

Potential Energy

Potential energy is produced when the position of an object is changed. There is only one timepiece that makes use of it.

Mechanical Watches

Mechanical watches have mainsprings that can be compressed – you wind them from their crown. The springs transfer the pent-up energy to the gears, which move the watch hands.

The technology behind the mechanical movement is the oldest. To find out more, check out the history of watches.

As there is a series of gears inside the timepieces, their mechanisms are very intricate. A lot of skill is required to make them. This is true of their automatic counterparts as well.

Another thing they share is the presence of power reserves. A mechanical watch’s power reserve would tell you how long it would take until you have to wind its mainspring.

Electrical Energy

Electrical energy is created by electrical charges. If you include kinetic watches, there are two types of watches that use this. The other is regular quartz watches.

Quartz watches

Quartz watches were introduced in 1969. Seiko created the first battery-powered units. The first one was called the Astron.

In these devices, the batteries send electrical signals to quartz crystals. They vibrate, and the frequency is measured by circuits. The vibrations are transformed to pulses that power the timepieces’ motors, resulting in the watch hands moving.

Some units that are battery-powered make use of solar energy. Citizen is a fan of making quartz watches that rely on light-sources. Just take a look at their Eco-drive line.

The movements are easy to make. This why quartz watches are the most affordable type.

Citizen Men's 'Eco-Drive' CA0649-06X

Check out more watch guides

Final Thoughts

Most watches are intricately designed. When we said they were engineering wonders, you now see what we meant.

Thomas Vanderlaan
When Thomas Vanderlaan was a child, the moment he learned about mechanical watches he was hooked. His first love being mechanical watches, he decided to pursue a career in engineering as he was entranced by the science behind its gears. As the years passed, his passion grew. Although he worked a hectic career as an automobile engineer, he’d always collect watches during his spare time.
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