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Feedback?Read through the following information about the Cisco Wireless Phone 9821 battery life.
Your phone contains a lithium ion battery. When fully charged, the battery provides:
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Up to 11.5 hours of talk time
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Up to 145 hours of standby time
Battery life depends on a number of factors, including:
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On time—Battery life decreases when the phone is turned on. Activities such as calls, messaging, application use, Bluetooth usage, and menu navigation consume power.
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Scan mode—The phone can scan access points in three different ways (Continuous, Auto, and Single AP). Using Continuous or Auto scan modes requires more power, which reduces talk time.
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Microphone audio—Talk time may reduce to about 8 hours when you select Noise removal or Optimize for my voice.
If you need longer talk times, it is advisable to have a spare, fully charged battery available.
Use only approved batteries that come with your Cisco Wireless Phone 9821 or are specified by Cisco. Use of unapproved batteries might be dangerous and invalidates the warranty on your phone. To obtain replacement batteries, contact your local dealer and use only Cisco specified batteries with the correct part number.
The expected lifecycle for a battery is two years. Based on the average usage, this corresponds to approximately 500 charges. You can check the date printed on the battery to calculate the age of the battery. We recommend you to replace the battery when it reaches its end of life.
Low battery warning
Your phone has three low battery warning levels. When the battery charge reaches each level, a low battery alarm sounds and a warning message appears on the screen. Depending on the warning level, you have a specific amount of time to either charge or replace the battery before the phone automatically powers off. The following table describes the low battery warning levels.
|
Level |
Warning appears at this battery charge level |
Onscreen warning |
Length of time that the warning stays on screen |
|---|---|---|---|
|
3 |
10% |
Warning: Battery is low. Charge or replace the battery. |
5 seconds |
|
2 |
2% | ||
|
1 |
The battery voltage is less than 3.45V and the phone will power off in 10 seconds |
Warning: Battery is low. Phone will power off in 10 seconds. |
Until the phone powers off |
The final countdown of 10 seconds is static. This warning disappears when you connect the phone to a power source or replace the battery.
