Seiko SAGV007 "Big Date" Titanium Perpetual Calendar

Model: Seiko SAGV007 / 7D48-0AD0

Year: August 2006

Features:

The Design. Produced for a brief period in 2008 and exclusively sold in Japan, this has become the grail Big Date for most Seiko collectors. A quintessentially accidental “limited edition” from Seiko, as its sudden discontinuation has made them very hard to find. Its dial is dark ivory with a subtle sunburst effect, and it's recessed subdials achieve a similar sunburst visual through their use of rippled, concentric circles. 

The Hybrid. A 7D48 “Kinetic” movement. Kinetic movements originally served as a hybrid pre-cursor to the Grand Seiko’s Spring Drive movement. Just like in an automatic mechanical watch, your arm/wrist movements spin a rotor that powers the watch. However, unlike a standard automatic movement, energy is stored in a capacitor and then passed through quartz crystal. 

The Complication. The main complication is a leap year Perpetual Calendar with Big Date. The main concern with an automatic perpetual calendar is the inconvenience of having to regularly reset it when it runs out of power. However, thanks to the “relay mode” you won’t have to worry about that, as your watch will enter a hibernation state if you haven't recently worn it. While hibernating the watch stops ticking, but a tiny IC stays powered and keeps track of the time and date. As soon as you pick the watch up the hands spring to life and the calendar and time set themselves accurately. It can stay in a state of hibernation for up to four years!

The Advantages. Being a hybrid between mechanical and quartz has several distinct advantages. Thanks to the quartz crystal the watch is accurate to +/- 15 seconds per month. However, unlike a quartz watch you don’t need to replace the battery every 1 or 2 years as the battery isn’t generating the power; your movement is. The recommended replacement for a Kinetic Capacitor is every 10-20 years! When fully powered, the watch has a huge 10-day power reserve.  

The Strap. Most commonly found on aftermarket straps, this has the original leather strap and deployant buckle from Seiko. It perfectly fits the shape of the cushion shaped case. 

Specifications:

Condition: In good condition, with cosmetic signs of wear. Just serviced by Seiko, with a new capacitor installed. Various swirls and and lines you’d expect to find on a titanium case. On the OEM curved leather strap and clasp.

Scope: No box or papers. 

Movement: 7D48 Kinetic Hybrid. 10-20 years of “battery” life, according to Seiko’s specs. 10-day power reserve, and a 4-year hibernation state if the watch is unworn.

Dimensions:

• Case Width: 40.0mm
  
• Case Thickness: 12.8mm
  
• Lug Width: 22.0mm