The manufacturer stated maximum number of cordless handsets that ... one handset to be used at a time, so can't be used like an additional (extension) phone you have connected to the same phone ...
Also replace of the original Cordless Phone Battery Pack BT183342/BT283342 BT166342 ... SN1196 SN1197 SN6196 SN6197 Compatible with AT&T Telephone Models: CL80100 CL81100 CL81200 CL81300 CL82100 ...
The manufacturer stated maximum number of cordless handsets that ... one handset to be used at a time, so can't be used like an additional (extension) phone you have connected to the same phone ...