Winding, automatics, and watch winders: what your movement needs

Two ways to charge a spring

Every mechanical watch stores energy the same way — in a coiled mainspring — but they are charged by two different means, and the distinction shapes how you live with the watch. A manual (hand-wound) movement is charged by turning the crown; an automatic (self-winding) movement adds a weighted rotor that swings with the motion of your wrist and winds the spring as you wear it. Neither is superior; they are different relationships. The manual watch asks for a small daily ritual and gives you a direct feel for its state of charge. The automatic asks to be worn and largely takes care of itself.

Hand-winding, done right

To wind a manual watch, turn the crown forward (clockwise, away from you at the top) in smooth, unhurried turns. You will feel the resistance increase as the spring fills, and on most movements you should stop at the first firm resistance rather than forcing past it — the mainspring is fully wound, and cranking harder strains the click and the spring's bridle. A typical movement takes perhaps 20 to 40 turns from empty. Wind it once a day, at the same time, and it will keep its best time — a fully wound spring delivers more consistent torque than one running down, and consistent torque is consistent rate.

Automatic watches can usually be hand-wound too, through the crown, which is the right way to start one that has stopped — give it 20 to 30 turns to get it running before putting it on, rather than relying on wrist motion alone to bring a dead movement up to speed. Some automatics have no hand-winding facility at all and must be started by shaking or wearing; their manuals say so.

What "power reserve" means for you

A movement's power reserve is how long it runs from full wind to stop — commonly 38 to 80 hours on modern watches. The practical consequence: a watch with a 40-hour reserve, taken off Friday night, is dead by Sunday and must be reset; a 70-hour movement worn Friday is still running Monday morning. Longer reserves are a genuine convenience for people who rotate watches, which is part of why the industry has pushed reserves upward. Knowing your watch's reserve tells you how often a desk-resting watch needs winding to stay alive.

Watch winders: the honest verdict

A watch winder is a motorized box that rotates an automatic watch to keep its rotor turning and the watch running while it is not being worn. The marketing implies this is good for the watch. For the great majority of watches, it is at best unnecessary and at worst mild over-use. A resting watch is not deteriorating — a stopped movement is the most benign state a watch can be in. Keeping a movement running continuously on a winder, by contrast, accumulates wear and consumes lubricant for no benefit, since you are not even using the watch. For a simple time-and-date automatic, the correct answer is almost always to let it stop and spend thirty seconds resetting it when you next wear it.

There is one real exception. A complicated automatic — particularly a perpetual calendar — is genuinely tedious and, during its change windows, slightly risky to reset from dead, because re-establishing the day, date, month, leap year, and moonphase is a careful procedure best done rarely. For these watches a winder earns its place: it spares you the elaborate reset and keeps the calendar advancing. If you own a perpetual calendar you do not wear daily, a quality winder set to the movement's recommended turns-per-day and direction is a reasonable tool. For everything else, save the money.

A mainspring needs only to be charged when you want the watch to run — by your wrist, by your hand, or not at all. Wind a manual watch once a day to first resistance; start a stopped automatic by hand; respect the screw-down crown; and ignore the winder unless a perpetual calendar makes it genuinely useful. The simplest relationship — wear it, or let it rest — is also the healthiest one for the watch.