S. Epson Caliber PX82A

The S. Epson caliber PX82A is a kinetic watch movement with a date.

The PX82 has been available to non-Seiko watch brands since at least July 2020.

Autoquartz / Hybrid Automatic?

The PX82A is a kinetic movement, which is similar to an automatic movement in how it uses kinetic energy from the motion of your wrist, to spin a rotor (aka oscillating weight) that is attached to the movement, which is designed to store the potential energy and release it in a way that translates to telling the time via hands on the dial.

As Seiko describes it:

“This watch generates “the electric energy” to power the watch, utilizing the movement of your body, and stores the power in the secondary battery.”

When it comes to the “auto-quartz hybrid” part of a kinetic movement, the “auto” element is limited to the winding rotor – everything else is quartz.

However, similar to solar-powered movements, the quartz part of a kinetic movement is slightly different in how it uses stored energy. The main difference is that it doesn’t use regular disposable silver oxide batteries that need changed every 2-3 years. Instead, kinetic movements are powered by rechargeable batteries (known as capacitors in the watch world), which are constantly being recharged when you wear the watch. Aside from the storage and transfer of energy in a kinetic watch, the rest of the movement, such as time-keeping and other functionality, is purely quartz.

Kinetic watches are often marketed falsely as never needing a battery changed. For example, this what Seiko says:

“Unlike conventional quartz watches, this watch does not use a silver oxide battery, thus eliminating the need for battery replacement.”

That is not entirely correct. While a kinetic watch will not need regular battery changing, the capacitors (rechargeable batteries) that power them, do not last forever. Eventually, the capacitor will need changed too – maybe 5 years, maybe 10, maybe sooner if you don’t keep your watch charged. Yes, that is a major downside that is often overlooked: if the kinetic watch battery is depleted from extended periods non-use, it may lose its ability to hold charge and will need replaced sooner than expected.

As you can see, it is cool technology that sounds great in marketing campaigns, but there are pros and cons to kinetic watch movements.

Video – Epson Hybrid Automatic Movement:

Power Reserve Indicator:

The PX8 Series features a built-in power reserve indicator so that you can know how much energy is stores in the capacitor.

This is achieved by pressing the button on the side of the watch case, located in the 2:00 position. Pressing the button will cause the seconds hand to quickly advance a certain amount of seconds depending on how much power remains in the battery. The amount of seconds indicates the current power reserve level. For ease in reading the power reserve indicator, it is best to press the button when the seconds hand reaches 12:00.

• Wait for the seconds hand to reach 12:00.
• Press the side button.
• Note where the seconds hand stops from :00 to :30.
• Use the chart below to determine how much power reserve remains.

Video of the power reserve indicator:

PX82A VS PX28A:

The main difference between the PX82A and the PX28A is that at this time, Caliber Corner cannot confirm that the Seiko caliber PX28A exists.

At the time of this post, the only watch brand claiming to use a Seiko PX28A movement is Vero Watch Company in their Forest Service Edition. As a result, various watch blogs and even search engine Al snippets all claims that Vero is powered by a PX28A calibre.

Until confirmation is provided, what we think happened is that the numbers were switched: PX82 > PX28. This makes sense since there is a PX8X line of movements, but there is not a PX2X line as far as we know.

Since the watch brand does not show images of the movements in their watches, it is creating caliber confusion in the community as folks are looking for information about a caliber that may not exist (further confusion may be caused by the fact that a PX28A battery does exist). Either way, it wouldn’t be the first time that a watch brand didn’t know the actual movement they are using in the watches they sell.

If a cal. PX28a indeed does exist, please post a photo of one in the comments below…

Important Notes:

• Do not let your watch completely drain of power.
• Do not attempt to set the date when the hands are between the hours of 9:00 PM and 1:00 AM.

Tech Sheets (pdf):

Additional Resources:

• More “Kinetic” movement mentions
• Read about Kinetic Energy on Wikipedia