Checking Of Batteries - Longines L590.2 Maintenance Manual

+
18
470Q
± 2 %
10. Checking of batteries
10.1
Stocking
It is advisable to keep batteries at a temperature of
15 to 25 ° C, with a humidity rate below 60 %. The
maximum period for stocking is two years.
It is not indicated to use a cold room for stocking
electronic movements or watches with their batter-
ies fitted , because the batteries are likely to be
damaged by internal crystallizati-on if the tempera-
ture is too low.
10.2
Handling
Never handle batteries with metal tweezers, which
would have the effect of short-circuiting them . It is
advisable to check batteries before use, according
to the following procedure, which consists of two
parts :
1 0.2.1 Electrical checking
1 0.2.2 Checking of appearance
Batteries which are not in perfect order should not
be used .
10.3
Electrical checking
During a minimum possible time, cause the battery
to discharge across a resistance of 470 ohms ( ± 2%
max.) to whole terminals is connected a voltmeter
of sufficient accuracy ( ± 1%) and internal resis-
tance (:;::: 10 kOhm/V, see diagram). Care should be
taken to see that the contacts between the various
elements, particularly those on the battery, are cor-
rectly made.
One second at the most after the battery has been
connected to the measuring circuit, the voltage
should not be below 1.30 V. This measurement does
not correspond to the real internal resistance , but
includes phenomena of electrode polarization, due
to the high current.
This test is subject to the following conditions :
1. It applied only to unused batteries which have
been in stock for less than two years.
2. If the test has to be repeated , it is necessary to
wait for at least 3 hours after the first test. Never-
theless , the measurement should be repeated
only when it is absolutely necessary.
3. The tests should be carried out at room tempera-
ture (20 to 25 ° C).
10.4
Checking of appearance
The shape of the battery must be co rrect. There
should be no sign of deformation (swell ing), nor
should the re be any white crystals or liquid near the
A
joint. If the battery is stained , wipe it with a clean
W
cloth (Selvyt). Never use a solvent.