Watch Winder's Battery Life

Many users are also concerned about battery life of their watch winder. Unless you want to keep your precious timepiece in a safe without any power outlets, one should then be concern. Otherwise, like me, the AC mains would be eventually used for my homemade watch winder project.

Just out of interest, let’s see what the battery life of a watch winder would be like.

Example:-
1) A motor draws about 60mA when loaded with a watch in its winding cup.
2) At rest, the circuit draws about 4mA.
3) If I use 4xAA dry cells, it has capacity of about 2500mAH for 20mA loads.

In the 950TPD mode,
2500mAh/4mA = 625 x 39 = 24375/24 = 10156/30 = 33.8 months

Explanation: -
The motor does not continuously turn, meaning drawing continuous 60mA, so I’ve taken the minimum current for calculations. Note that the motor remains at rest about 90% of the time.

Here’s what I did…
Divide battery capacity with motor current, and then multiply by the ratio of the sequence (Total cycle time divide by ON time). I’ve used my own sequence for this calculation.

Next, I divide by 24 hours to determine the number of days.

Lastly, I divide by 30 days to know how many months the battery pack can power up this unit.

Theoretically, it should have enough juice for approximately more than 30 months, or about 2.5 years. (90% of 33.8 months).

From this exercise, you will noticed that battery life depends on 3 important factors:-
a) current drawn by the motor,
b) battery capacity, and
c) winding sequence ratio of ON and OFF times.

So, hypothetically if I have a higher battery capacity and a motor that draws lower current, I can perhaps extend the battery life. The winding sequence would then be dependant on the motor rpm.

Labels: DIY watch winder, winding sequence

What a Winderful World

Love it or Hate it, watch winders are devices that will provide convenience to a watch collector who wants to keep each watch “exercised” and not wound down.

Many websites have given definitions to what a Watch Winder is and most of them are written by owners or staff of shops that sell them. Few are written by watch lovers and admirers. I for one am only a watch admirer intrigue by the handcrafted timepieces and the device which some people say is an amazing invention.

Watch winders come encased in wood, metal or plastic. There are those that can be placed on table-tops and those that have their own cabinets. From a single-watch winding mechanism to multiple mechanisms.

Some people have tried their hand at making their own watch winder. I’m glad they succeeded. But none of them comes close in terms of esthetics, function and reliability of those professional products sold in the market.

In short, today’s watch winders are no different from those in 2003. Perhaps now better motors and gearing systems were used and different types of housing were created. But few things in a watch winder unit remain,

1. There will always be a winding sequence; Turn-and-Rest,
   
2. Watches are rotated belt-driven or with geared / servo motors,
   
3. A programmed circuit board commands the motor to task
   
4. Motors have constantly been the heartbeat of the winding mechanism, and
   
5. Two schools still debate on the use of a watch winder.
   

Labels: watch winder, winding sequence