As tradition and design of the cordless phone,the hanset need to replace on The cordless phone every time after usage.It can activate the battery,charge the lost of capacity during usage and lost of self-discharge.But we suggest fully discharge the battery after used for three month,and fully charge the battery again so as to recover the initial capacity and discharge performance. The user have better take off the handset from the cordless phone if long time not use the phone, avoiding over charge the battery. Though the phone is turn off,the system still discharge at small current.So the battery should be took off from the cordless phone and put it on open circuit state.When need to use,then charge the battery again.