Fuji Electric ALPHA5 Smart, User Manual

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CHAPTER 11 ABSOLUTE POSITION SYSTEM
Calculation of Battery Life
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11.5 Calculation of Battery Life
The battery life elapses if the control power of the servo amplifier is left turned off for 35,000 hours.
During actual operation, the power-on and shutoff cycles are repeated. An example of calculation of
the service life in this case is shown as a reference. Note that the value is merely a calculated value
and it is not guaranteed. Note, too, that the service life becomes shorter under some ambient
environmental conditions.
 Operation condition
Operation No operation
1 day 10 hours 14 hours
1 year* About 261 days (= 365 days x 5 / 7) About 104 days (= 365 days x 2 / 7)
* Assumption: operation on Monday through Friday, no operation on Saturday and Sunday
 Current consumption
Current consumption in power-on phase: 0.0075 mA
Current consumption in shutoff phase: 0.0415 mA (= 0.0075 mA + 0.034 mA)
 Calculation of service life
Annual battery capacity consumption
(10 Hr × 0.0075 mA + 14 Hr × 0.0415 mA) × 261 days + 24 Hr × 0.0415 mA
× 104 days = 275 mAh
Annual battery life estimation
1600 mAh / 275 mAh/year = 5.8 years
Hence the service life of the battery is about 5.8 years* under the above operation conditions.
* However, the battery manufacturer recommends to stop using the battery after three years of
operation. Periodic replacement within three years is recommended without relations to the
operation conditions.
* In the case of wrong wiring in encoder cable, the battery life possibly becomes extremely short.