How To Check The Quartz Watch Battery Capacity
Most quartz watch use silver oxide batteries, which are small in size, large in capacity and stable in output voltage, making them ideal for use on quartz watch. Quartz watch with battery specifications and types are also very much, in addition to silver oxide batteries, there are lithium batteries, alkaline batteries. Generally speaking, the capacity of the battery and its volume, the larger the volume is also the greater the capacity of the battery capacity also determines the battery life.
Measuring the performance of the watch battery equipment
Unlike ordinary dry batteries, the silver oxide cell discharge curve is very flat, it will not be like a dry battery, with the use of the voltage is gradually reduced (see photo), this time to keep the watch travel time is of course very good. But also bring a problem, that is, can not measure the voltage to determine how much battery capacity, silver oxide battery nominal voltage is basically 1.55V, and this voltage will remain until the battery life is about to end before. But in order to avoid affecting the normal wear of the watch, many quartz watch are equipped with a battery voltage warning function, is stopped by the second hand for 4 seconds, and then the rapid jump with the 4 down that , Once the phenomenon occurs, the watch can walk about 10 days or so, to remind you to immediately replace the battery. This function is also called "E.O.L", but there is no center second hand quartz watch, there is no such function.
In fact, as with all the batteries, the new battery capacity is not exactly the same, the battery capacity of the unit is expressed in milliampere hours (maH). So far, has not heard of a kind of instrument, you can quickly, lossless and accurate detection of silver oxide battery capacity, as early as 20 years ago, I heard that foreign countries have been rewarded with heavy money to the equipment Invention, but now still no one can give it out.
Battery manufacturers to do the battery factory quality inspection, are still used as a batch of battery discharge experiments, is to test the battery connected to a load, the formation of a certain current closed loop, until the battery voltage down to a certain value, Discharge current multiplied by the discharge time is the actual capacity of the battery. When the experiment is over, the battery will be scrapped.
Now the rapid detection of the watch battery are heavy-duty discharge, see the battery at different discharge current, the pressure drop, because with the use of the battery internal resistance (also known as battery resistance) will increase; Once the discharge current increases, the closed-circuit voltage will suddenly drop.
Like some Swiss-made quartz calibration instrument, are attached to the battery heavy-duty discharge test function, the load resistance of 2000 ohms, 50 ohms and 5 ohms several files (see photo). In fact the watch with silver oxide batteries also have different uses, such as high current output type and low current output type, their electrolyte is different, the former is usually used for light alarm LCD quartz watch, the latter for the pointer Type quartz watch.
When the button is pressed, the load resistance is turned on, immediately observe the extent of battery voltage drop, different batteries should have different indicators, but generally can not be less than 1.35V voltage.
The size of the cross-sectional area of the battery, the test temperature and test results are related to the larger battery, the ambient temperature is relatively high, the voltage drop less.
Battery heavy load experiments, only about the estimated capacity of the battery, but can not reach the precise measurement of the value, and this experiment can not do a long time, because it is more consumption of battery power.