The power reserve function can easily be considered one of the most useful mechanical watch complications ever invented.
If you’ve never encountered one, or are not quite sure what it is, it’s safe to say you’ve come to the right place. In this guide, we will be reviewing the power reserve complication and listing our top 5 watch models from various different brands.
You’ll be able to appreciate how the power reserve can be the main focus of a timepiece, as well as the times that it plays a more supportive role on a watch dial. The innate functionality and simplicity allow for extreme versatility and integration into both of these settings.
Scroll through with us as we recap the power reserve and its beginnings through the following sections:
Top Power Reserve Watches
- Hublot MP-05 LaFerrari All Black Ref. 905.ND.0000.RX
- HYT H4 Panis-Barthez Compétition
- Jaeger-LeCoultre Master Ultra Thin Réserve de Marche Ref. Q1378480
- Zenith Defy El Primero 21 Ref. 49.9000.9004/78.R582
- IWC Big Pilot’s Watch Edition “Le Petit Prince” Ref. IW501002
The power reserve timepieces that have made it to our top list are not necessarily the ones possessing the longest power reserves. We’ve also given consideration to the way in which the indicator is implemented into the watch’s design.
The links above will allow you to jump directly to one specific model. Otherwise, keep scrolling down for our full recap of the power reserve complication.
See Bespoke Unit’s Watch Reviews
What Does Réserve De Marche Mean?
“Réserve de Marche” is the French translation for Power Reserve. The term is commonly used by watch brands with French watchmaking heritage, such as Jaeger-LeCoultre and F.P. Journe, when naming their power reserve models.
This begs the question – what exactly is a power reserve watch?
What Is A Power Reserve Watch?
A power reserve watch is one which contains the power reserve complication; this usually looks like a “fuel gauge” on the dial of a mechanical watch. The objective is to give the wearer an idea of how much longer the watch will run if it is not wound.
Given the fact that automatic watch movements don’t require hand-winding as long as they’re actively worn, this complication may play a more vital role in a manual timepiece.
Nevertheless, they have also been implemented in self-winding watches with great success.
Brands have taken great liberty in designing all different kinds of displays for power reserves in their watches. There really aren’t many rules around how a power reserve is supposed to look. They simply have to indicate “more” or “less”.
The loose definition has led manufacturers to create a wide range of different power reserve displays. It may even be true that the flexible nature of the complication is what has made it so widespread.
Luckily, “widespread” here does not entail overdone. Power reserves are popular because they’re truly useful. And in the majority of applications, they add a fascinating bit of character to the watches they accompany.
History Of The Power Reserve Complication
The earliest power reserve indicators were used not on wristwatches but on marine chronometers. These timekeepers were necessary for determining latitude while at sea.
If the instrument were to run out of power and stop tracking time, the crew would no longer be able to rely on it for navigation. Subsequently, an indication of the remaining energy was critical, and allowed crew to wind the marine chronometer whenever it ran down.
The first wristwatch with the power reserve complication was invented by Breguet in 1933, though it did not progress past the prototype stage. The first one available for sale was released by Jaeger-LeCoultre about two decades after its emergence.
Though designs and watchmaking technology have evolved throughout the last century, the mechanical concept behind the power reserve remains the same. The register indicates how much tension the mainspring is under. The greater the pressure, the more potential energy stored within the barrel and which can be used to keep the watch ticking.
Via all different kinds of complex horological mechanisms, the most talented watchmakers have brought you the power reserve timepieces we highlight next!
Best Power Reserve Timepieces
1. Hublot MP-05 LaFerrari All Black Ref. 905.ND.0000.RX
Hublot’s MP collection holds the brand’s boldest propositions, as well as the most exclusive. The LaFerrari All Black is no different.
In fact, it’s one of the pieces that has helped Hublot earn a spot in the league of haute horlogerie. It’s also no surprise it shares the name of Ferrari’s latest and most highly-demanded sports car.
The most remarkable aspect of the LaFerrari is its power reserve – an outstanding 50 days, or 1200 hours long. It accomplishes this with the help of 11 barrels. The time and power reserve are then indicated in a series of anodized cylinders.
The significant number of mainspring barrels have been implemented front and center in the design to simulate the look of the engine bay of the actual Ferrari LaFerrari. There’s also a sapphire window into the vertical tourbillon on the bottom flank of the case.
All in all, Hublot has done an exceptional job of imparting a high-tech character to this, the longest power reserve watch in the industry today. And while this timepiece has also been released in sapphire, we think this PVD titanium version is the most fitting one.
- Brand – Hublot
- Model – MP-05 LaFerrari All Black (see on Hublot’s site.)
- Power Reserve – 50 Days / 1200 Hours
- MSRP – $345,000
2. HYT H4 Panis-Barthez Compétition
HYT is an independent watchmaker not often discussed in watch circles. With offerings like their H4 Panis-Barthez, the brand has slowly but surely earned itself the wrists of watch aficionados the world over.
The Panis-Barthez special edition boasts the same high-tech essence that has characterized HYT’s, along with additional details drawn from the sports car racing team.
As with all HYT watches, the first eyecatching element of the H4 is the fluid time display. Unlike any other timepiece, HYT watches employ a fluidic module to indicate the hours on their timepieces.
The minutes are recorded at center, regulator style. There’s also a small seconds register at 9 and, naturally, a power reserve indicator at 3. Both of these subregisters boast design inspiration from sports car dashboards, and add an appealing splash of color to the skeletonized dial architecture.
The entire caliber is cased in a black DLC titanium case, further extending the high performance nature of the timepiece.
Lastly, this HYT boasts a hidden mechanical illumination function. It’s “charged” via the crown at 4 o’clock and likewise activated by pressing it.
We could try to describe it, but the video below says it all.
View this post on Instagram
- Brand – HYT
- Model – H4 Panis-Barthez Compétition (see on HYT’s site.)
- Power Reserve – 65 Hours
- MSRP – $95,000
3. Jaeger-LeCoultre Master Ultra Thin Réserve de Marche Ref. Q1378480
The Master Ultra Thin Réserve de Marche is an iconic watch from an iconic brand, Jaeger-LeCoultre, and one that beautifully exhibits how the power reserve can be implemented in a very elegant way.
The watch’s ultra-thin case easily lends itself to formal settings, tucking under even the tightest of scuffs. It must also be noted that the thin profile does not sacrifice automatic winding, as can be verified via the sapphire caseback.
The power reserve subregister is perfectly balanced on the azurite blue dial by the date and small seconds subregisters. Surrounding these are dart-like applied hour indices, s well as dotted minute markings.
Overall, the Master Ultra Thin Réserve de Marche is almost understated, particularly when compared to our two previous contenders. Yet this is what makes it so special.
This is not the timepiece intended to draw all the eyes in the room to your wrist. Its intended to be functional, aesthetically alluring, and unobtrusive.
It performs all of these tasks perfectly and with subtlety, which is why we think that when it comes to power reserves, the JLC Réserve de Marche is hard to beat.
- Brand – Jaeger-LeCoultre
- Model – Master Ultra Thin Réserve de Marche (see on JLC’s site.)
- Power Reserve – 43 Hours
- MSRP – $8,850
4. Zenith Defy El Primero 21 Ref. 49.9000.9004/78.R582
Zenith‘s El Primero models have generally been presented in traditional cases with classical designs. With the recently-released Defy El Primero 21, Zenith demonstrates that they, too, can be avant-garde.
The previous El Primero chronographs have been very successful in their own regard. But in recent years Zenith saw it’s brand status diminished and almost forgotten.
With this Defy EP21 , Zenith established that they can, in fact, be progressive both in looks and in technology. They are, after all, the creators of the first automatic chronograph.
Not only have they upgraded the case material, it’s completely crafted from black ceramic, but the chronograph functionality has also been enhanced. So much so that it requires its own separate escapement for 1/100th second timing.
The power reserve takes up little space on the skeletonized dial, yet its dimensions are casually perfect.
The Defy reminds us that a power reserve need not be overcomplicated nor large. With the smallest amount of indication, it’s able to communicate its message and perform its function flawlessly. And though it plays its part quietly, it’s a critical factor in making the Defy El Primero 21 such a well-rounded and bold power reserve chronograph watch.
- Brand – Zenith
- Model – Defy El Primero 21 (see on Zenith’s site.)
- Power Reserve – 50 Hours
- MSRP – $12,200
For an in-depth look at this Zenith, check out our review of the Defy El Primero 21.
5. IWC Big Pilot’s Watch Edition “Le Petit Prince” Ref. IW501002
IWC’s Big Pilot model line has been incredibly successful since its re-release in 2002. By employing the sunray blue dial of the Le Petit Prince series in this 2018 offering, IWC has made a classic timepiece even more tempting and desirable.
With the IW5010-02, the essence of the Big Pilot is unchanged – the case maintains its large 46.2mm construction, the riveted strap, and the large white luminous indices and center hands.
But the grained dial adds an additional level of attraction that only a well-executed blue dial can bring. Unfortunately, it’s texture and depth does not truly come through in images. Take it from us, though, the Le Petit Prince blue is one of the most beautiful blue dials we’ve ever encountered.
The power reserve complication in this instance holds plenty of real estate on the dial. It also boasts clear printing indicating what it records: the massive power reserve that many of IWC’s models are gifted with, including this one.
It also possesses a contrasting concentric circle engraved texture, which makes it even more visually interesting when glancing at the timepiece. IWC has made it a prominent landmark, one not to be overlooked, and made it perfectly readable and therefore, perfectly useful and fitting on this Le Petit Prince Big Pilot.
- Brand – IWC
- Model – Big Pilot’s Watch Edition “Le Petit Prince” (see on IWC’s site.)
- Power Reserve – 7 Days / 168 Hours
- MSRP – $12,900 [Browse On Amazon]
More Guides & Articles
What did you think of our picks for the best power reserve watches? Let us know in the comments if you disagree, or if there is a specific reference you believe should have made our list!
- On The Wrist Review Of Zenith Defy El Primero 21
- Moonphase Complications: What Are They & Which Are The Best Ones?
- All Of Our Watch Reviews
- How Much Do You Know? View Our Watch Knowledge Guides
"The power reserve complication is easily one of my favorites. Not only because it's actually useful on a watch, but their presence also gives me plenty of things to talk about with admiring onlookers."Rating: 5.0★★★★★