Calculation Of Battery Life - Fuji Electric Alpha7 VV User Manual

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
1 day 10 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 case of wrong wiring of encoder cable, the battery life is possible to be extremely short.
CHAPTER 11 ABSOLUTE POSITION SYSTEM
Operation
14 hours
No operation
Calculation of Battery Life
11
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