Nortel 4025 User Guide

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Charge the batteries for at least six to seven hours before using the 
handset for the first time. This protective measure extends the service 
life of the batteries.

•

The maximum power output is attained only after three to five 
charging and discharging cycles.

•

Do not leave the handset connected to the charger longer than one 
month without using.

•

The batteries can be charged and discharged hundreds of times, but 
eventually they will be worn out. If the operating time (that is, talk and 
standby time) is significantly shorter than usual, it is time to replace 
the batteries.

•

To maintain optimum operating time, the batteries should be 
discharged from time to time by not placing the handset in the 
charger but leaving it switched on until it switches itself off. Use only 
this method to discharge the batteries.

•

Extreme temperatures influence the charging capability of the 
batteries.

•

Empty batteries require six to seven hours to fully charge.

•

When a fully-charged handset is switched off, it discharges in 
approximately one week. 

•

When batteries are fully charged, the handset has approximately 20 
hours of talk time or approximately 200 hours of standby time.

The handset display screen shows the battery charge status. When the 
battery capacity is almost exhausted, an alert tone sounds in the form of 

CAUTION
Avoid placing the handset in the charger when fully-
charged batteries have been removed from the handset 
and inserted again. They can become overcharged.