Timepieces:Education & Repair
You replace them every day, but do you know what they are? Here's
a quick lesson
by David A. Christianson Certified Master Watchmaker
cell, or battery, is a tiny packet of energy that can drive a quartz watch
for up to 10 years or more, depending on the size, chemistry, design, quality
and efficiency of the watch. The famous "five-year battery" doesn't
exist it's the quality and design of the watch that allows it to run
that long on a single cell. Watches operating up to 10 years use a larger
The button watch cell comprises a metal container sealed against leakage.
The larger portion is the positive side, and the little button on the bottom
is the negative side (see drawing). If you look into your battery cabinet,
you'll notice a large assortment of watch cells that vary in diameter and
thickness. Some with the same diameter have different thickness; some of
the same thickness have different diameters. This variation is due to the
watch movement's needs and the outer watch design.
In general, a power-hungry or inefficient watch requires a larger cell
to run it for about two years. An efficient watch requires a very small
cell to run it for a year or a larger cell to run it for several years.
In the vast majority of cases, you can't change the size of a cell already
in a watch. That's determined by the watch and movement design.
The dominant chemicals in watch cells are silver oxide and lithium. Mercury
cells are produced overseas but are banned in the U.S. because they create
an accumulated environmental hazard.
Silver oxide cells are the most common. They produce 1.5 volts of energy
and can remain packaged and on the shelf for three years and last a year
or more in the watch. However, you don't know how long they sat at the manufacturer
and the distributor.
The smaller silver oxide cells don't have the capacity to power watches
designed to run for five years on a single cell. It takes a larger capacity
(larger size) cell. That's why you'll find men's watches designed to run
the full five years while, with a few exceptions, women's watches are generally
too small for the larger-capacity cells.
Lithium cells last longer than silver cells because of their slower deterioration.
They tend to be much larger than silver cells but can be very thin.
Handling and Disposal
Silver and lithium cells can explode if heated. Ingestion by infants and
children can cause serious illness or death. Exercise care when collecting
and disposing of expended watch cells. Collect them in plastic containers
with small openings (such as plastic milk jugs). Even though expended, each
cell maintains a minute amount of energy. When randomly stacked in a container,
the cells can connect in such a way as to multiply their remaining energy
and create enough heat to cause an explosion. A plastic milk jug, with its
restricted neck opening, can contain any of these potential missiles.
To dispose of expended cells:
- Give them to your local solid waste management district or environmental
waste collection facility.
- Sell them to a battery recycler.
- Donate them to the American Watchmakers-Clockmakers Institute's Edu-
cation, Library and Museum Trust. Proceeds from the reclamation and sale
of expended watch cells are used to train new watchmakers and clockmakers
and to fund continuing education programs. Send them (packaged in cardboard
boxes) to AWI-ELM Trust, Battery Collection Program, 701 Enterprise Drive,
Harrison, OH 45030. The postage is deductible as a business expense. Upon
receipt, AWI will send an acknowledgment and receipt.
Next Month: Battery Replacement Procedures and Profits
David A. Christianson owns Christianson Jewelry, Kendallville, IN,
and is a director and first vice president of the American Watchmakers-Clockmakers
Institute. He is a Certified Master Watchmaker and a Fellow of the British
Horological Society. He discusses watch repair in this column each month.
Questions, suggestions and comments can be sent to Professional Jeweler,
1500 Walnut St., Suite 1200, Philadelphia, PA 19102, e-mail askus@ProfessionalJeweler.com.
Copyright © 1998 by Bond Communications.