Watchmakers have been plagued by issues of power since time immemorial; it’s been a perpetual quest to keep watches ticking for as long as possible. How long can a mechanical movement last until the mainspring is fully depleted? How long should it last to be considered practical enough for everyday wear? Well the short answer is, you can never have too much power.
But what constitutes long power reserve? Generally speaking, anything that lasts more than one week is a big step up from the norm. Seven days is the benchmark. Beyond that, we’re looking at serious power playing chops.
IWC Portugieser Automatic
No. of days: 7
There was an advertisement run by IWC in the mid-2000s featuring the self-winding Portugieser (then it was called Portuguese) with a tagline that read: “If this watch stops, please call a doctor. It means you haven’t moved for seven days.” You can’t help but smirk at the sheer hubris behind the ad and the brand, but seven days of power reserve is truly a big deal, especially for a self-winding movement, which also means there’s an awful lot of winding to do.
Luckily for the Portugieser Automatic, it has one of the most efficient winding devices in the business. And it’s proprietary to IWC, having been invented by its technical director in 1944. Named the Pellaton Winding System after its creator, Albert Pellaton, it is based on a pawl-winding mechanism that enables the oscillating weight to wind the mainspring bidirectionally, converting even the slightest wrist movements into useful kinetic energy.
Calibre 52010 stores over 168 hours of power in two barrels arranged in series.
The oscillating weight has to complete over 2,000 turns in order to wind the mainspring completely, and this subjects the components to a high level of stress and friction. So to lengthen the lifespan of the movement, the Schaffhausen manufacture uses high-tech ceramic components, which are difficult to produce but virtually free from wear-and-tear.
Calibre 52010 stores over 168 hours of power in two barrels arranged in series. Ordinarily, a gain in autonomy would come from some kind of compromise somewhere, usually in precision. But despite offering extended power reserve, its regulator oscillates at a reasonably high frequency of four hertz or 28,800 vibrations per hour (vph), which is more than adequate for quality timekeeping.
IWC Portofino Hand-Wound Eight Days
No. of days: 8
The hand-wound Portofino could theoretically run for nine days, but IWC puts it down for just eight, setting one entire day aside so that the driving torque remains constant throughout. Still, eight days is an incredible length of time. Interestingly, with the mainspring fully wound up, the barrel stores 1,300 millijoules of energy, which according to IWC, is roughly equivalent to the amount of force needed to lift chocolate bar for a distance of 130cm.
With the mainspring fully wound up, the barrel stores enough energy to lift a chocolate bar.
Calibre 59210 is a beautiful movement generously decorated with Geneva stripes. That it has no oscillating weight is fantastic news because nothing obstructs the view seen through its extra-large exhibition caseback. Another thing that’s extra-large is the barrel which measures 1.7cm and accommodates an 86cm-long spring, versus the usual 50cm springs found, for instance, in the manufacture’s chronograph models. It peeks out from underneath the top bridge, showing just a hint of the snailed finishing expertly applied by the watchmakers of IWC.
Panerai Luminor 8 Days GMT PAM233
No. of days: 8
To pack more power under the hood, Panerai went with three spring barrels all arranged in series for optimal force and eight days of power reserve. Calibre P.2002 was one of Panerai’s earliest in-house movements and it helped define long power reserve as one of the cornerstones of its watchmaking philosophy. As a matter of fact, it was christened after the year when Panerai made the momentous decision to go with in-house movements.
This movement helped define long power reserve as one of the cornerstones of Panerai's watchmaking philosophy.
Cased in the classic Luminor, it has a unique linear power reserve display, which is found on many Panerai models made during the mid- to late-2000s. Utilising a free sprung balance equipped with a stop-seconds device implemented obviously for the sake of chronometric precision, Calibre P.2002 oscillates at 28,800vph, which as discussed before, is a fairly unusual feature among long power reserve movements. Indeed, if the manufacture should decide to decrease its frequency, the movement would stay powered for even longer than eight full days.
Chopard L.U.C Quattro
No. of days: 9
Since the day it was founded, Chopard’s L.U.C high watchmaking site in Fleurier was not like ordinary, industrial watch manufactures, and the nine-day Calibre L.U.C 98.01-L is testament of this innovative spirit. It is the world’s first four-barrel movement put together for a grand total of 216 hours of power reserve, which adds up to just about nine glorious days of continuous timekeeping.
A beautifully finished hand-wound movement, it features two sets of twin stacked barrels arranged in series. Each barrel packs a 47cm spring, so all four of them add up to a whopping 188cm of sheer unadulterated power.
Each barrel packs a 47cm spring, so all four of them add up to a whopping 188cm of sheer unadulterated power.
What’s also impressive about the Calibre L.U.C 98.01-L is how compact its entire structure is in spite of the long power reserve. Measuring just 28.6mm in diameter, it allowed Chopard to case it in the dressy gent’s L.U.C Quattro, a very wearable 43mm in diameter and 8.84mm in thickness, which is really not very thick at all. More importantly, the Chopard L.U.C Quattro with its 28,8000vph frequency is a COSC-certified watch, offering +6/-4 seconds per day accuracy.
Panerai Luminor GMT 10 Days PAM986
No. of days: 10
Following in the footsteps of the Calibre P.2002, Calibre P.2003 is Panerai’s second in-house manufactured movement and it shares many traits, including a free-sprung balance wheel with variable inertia, four-hertz frequency, zero-reset, and three spring barrels providing long power reserve. Where it stands out, however, is in the automatic transmission—Calibre P.2003 was the first Panerai in-house self-winding movement—and a two-day boost in the power reserve department for a total of 10 days as opposed to eight.
Calibre P.2003 was the first Panerai in-house self-winding movement.
Positioned in series, the three spring barrels are arranged such that two of them are stacked one atop the other and they jointly channel stored energy to the third barrel, which is geared to the going train, which in turn moves the needle on the linear power reserve display. This movement construction is an Officine Panerai patent and is designed to deliver an even, optimal force that remains stable irrespective of the movement’s state of wind.
Blancpain Villeret Tourbillon 12 Days
No. of days: 12
With a power reserve capacity of 288 hours, you’d expect the Blancpain Villeret Tourbillon 12 Days to dominate the wrist like a behemoth, but miraculously it doesn’t. As many Villeret references tend to be, its placid elegance belies an immense technical feat that reflects Blancpain’s perpetual quest for horological innovation.
Identified by the beautiful flying tourbillon with its signature off-centred extra-large balance wheel, the movement Calibre 242 pushes the limits of long power reserve set by its predecessor, Calibre 25. Launched in 1998, Calibre 25 was at that time the world’s thinnest hand-wound flying tourbillon with an eight-day power reserve. While retaining all of its key characteristics, the contemporary version brought a little more to the table, updating the watch with all the trappings of 21st century watchmaking techniques.
Blancpain used very traditional solutions but executed them with utmost finesse.
To pack 12 days of reserve energy in such a svelte package—the watch measures just 42mm in diameter and is no more than 11.65mm thick—Blancpain used very traditional solutions but executed them with utmost finesse. What we have is a single mainspring barrel which has been enlarged both in diameter and thickness, such that it is almost as thick as the movement itself. Calibre 242 is also a self-winding movement, which means that as long as the watch is being worn, it would always be in the optimum state of wind.
As a matter of fact, the movement could technically keep running for 14 days—two more than is declared. However, because issues such as chronometry and reliability are important to Blancpain, the manufacture prudently decided to go with just 12, which as we know is already four to five times longer than the norm.
Vacheron Constantin Patrimony Traditionnelle 14-Day Tourbillon
No. of days: 14
Vacheron Constantin take us comfortably past the 10-day mark with this magnificent hand-wound movement. Calibre 2260 is such a work of art, being both aesthetically and technically accomplished. As advertised, its power reserve is a cool 14 days—that’s two entire weeks of leaving the crown untouched. The beautifully hand-crafted Maltese cross-shaped tourbillon carriage rotates once per minute and will make 20,160 rotations from start to finish.
Calibre 2260 is such a work of art, being both aesthetically and technically accomplished.
Vacheron Constantin achieves this amazing feat using four spring barrels stacked in pairs, which unfurl slowly and simultaneously. Contributing to the long power reserve is the laidback oscillating frequency at just 18,000vph, which some might feel is a little on the slow side. But bonus points go to the amazing views of the tourbillon and regulating device, letting you admire everything including the balance wheel, hairspring and escapement.
Bovet Amadeo Fleurier Tourbillon Braveheart
No. of days: 22
From two weeks we go to three with a day to spare in this jaw-dropping Bovet number. Indeed, Bovet can be credited for making some of the most astounding watches on the planet. The Amadeo Fleurier Tourbillon Braveheart offers six patented technical feats, two of which have to do with the way it generates and stores energy, allowing the movement to stay powered for no fewer than 22 days.
This colossal appetite for power is supported by two enormous barrels taking over half of the movement’s surface area, and each storing a mainspring measuring 104cm. And it doesn’t guzzle up all the power at once but sips it slowly, as Bovet is a specialist in long power reserve and this movement has been calibrated to utilise energy efficiently.
Bovet is a specialist in long power reserve and this movement has been calibrated to utilise energy efficiently.
Winding the barrels of this movement is extra pleasurable because the open-worked dial exposes all of the internal mechanism. But Bovet makes sure to reduce the number of turns required for the mainsprings to be fully wound. Typically, the longer the power reserve, the more turns are required to wind up the springs. Here’s where the two patents come in.
First, a new spherical differential gear on the winding stem doubles the gear ratio, which halves the total number of turns required to fully wind the movement. Within the spherical differential, we find the second patent, which involved a new double-conical teeth design of the satellite micro-pinions. This can be viewed through an aperture on one side of the watch’s double-faced dial.
A. Lange & Söhne Lange 31
No. of days: 31
A power-packed technical tour de force, Lange 31 is a monster in size and strength. It went unchallenged with the world record for longest power reserve for nearly a decade, achieving this astounding feat with two mainsprings that are each 10 times longer than standard mainsprings. Measuring 185cm, they are contained within two 25mm barrels stacked one on top of the other and occupying more than half of the entire area of the movement, Calibre L034.1.
Coming up for air just once every 31 days, or 744 hours, means we’re dealing with serious powerful stuff here. Managing all this power properly necessitates a system that allows the potential energy to be dispensed evenly so that the watch tells the time consistently. Indeed, with great power comes great responsibility, which in this watch comes in the form of a constant force escapement that helps keep the barrel in check.
With great power comes great responsibility, which in this watch takes the form of a constant force escapement.
It works by feeding a fixed amount of energy to the escapement once every 10 seconds, allowing the balance to always oscillate with the same ideal amplitude. You will see a triangular cam attached to the fourth-wheel arbour, which controls the mechanism with a pivoting lever that ‘charges’ the remontoir spring, which in turn channels the energy to the escapement. And at the end of the power reserve duration, on the 31st day, a limiter mechanism kicks in to stop the movement.
Lange 31 has a crown but it’s not used to wind the movement. For that, a special winding tool that comes with the watch must be inserted into the square-shaped socket in the recess of its sapphire caseback.
Hublot Masterpiece MP-05 LaFerrari
No. of days: 50
You simply can’t co-brand anything with a brand like Ferrari without packing it with serious horsepower. Or in the case of the Hublot Masterpiece MP-05 LaFerrari, ridiculously long power reserve. This record-breaking three-dimensional racing machine for the wrist delivers an incredible 50 days of non-stop high-octane action that’s truly beyond belief. Not only was it co-branded with Ferrari, it was designed with the Ferrari teams so both the watch and the car share technical and aesthetic codes.
This record-breaking three-dimensional racing machine for the wrist delivers an incredible 50 days of non-stop high-octane action.
Where the car has a mid-mounted 12-cylinder engine, the watch uses an 11-barrel movement arranged in a straight line and vertically just like a spinal column. Unfurling simultaneously rather than one after another, the barrels are protected from excessive friction by a row of synthetic rubies. At the end of the column is a suspended oversized tourbillon carriage measuring 14.5mm.
Like Lange 31, special tools are needed to wind the movement. Hublot provides a special electric screwdriver and tool kit for this as well as setting the time.
Vacheron Constantin Traditionnelle Twin Beat Perpetual Calendar
No. of days: 65
Trust Vacheron Constantin to think out of the box in coming up with a movement that takes the cake in the power reserve department. As the defending champion among movements with long power reserve, the Traditionnelle Twin Beat Perpetual Calendar can last for an outrageous 65 days.
Whether self-winding or hand-wound, perpetual calendars stand to benefit the most from long power reserve. With a number of exceptions, they can be quite a hassle to adjust when left dormant for too long, what with all those hidden pushers and pesky tools. So the Traditionnelle Twin Beat Perpetual Calendar offers a smart design that has two modes: an active mode and a unique stand-by mode. The ‘twin beat’ in its name refers to its dual frequency escapement, five hertz (36,000vph) and 1.2 hertz (8,640vph), provided by two balance wheels.
Traditionnelle Twin Beat Perpetual Calendar offers a smart design that has two modes: an active mode and a unique stand-by mode.
When the watch is being worn, the five-hertz frequency offers steady and precise timekeeping. When it’s not being worn, it can be switched to 1.2 hertz so the movement beats at a far slower rate, saving precious energy whilst still keeping time. If the movement is constantly in stand-by mode, it lasts the full 65 days. In active mode, it stays powered for four days, which is already better than most five-hertz movements.
The watch is also more energy efficient than traditional perpetual calendars because Vacheron Constantin implemented instantaneous jumping indicators for the date, month and leap year. Boosted with patented jumping mechanisms completely redesigned to utilise a sprung dual-gear compound system, it requires four times less torque and promises no loss of power even when all the displays advance simultaneously at midnight on 1 January each year. That’s the kind of power play we’re happy to get behind.