I had a spare 6.5 v dc transformer from an extra cordless phone. I cut the cord off and connected 2 alligator clips to the cord. Then I got a 6v battery, connected the cord and plugged it into my base. It worded all 6 of my phones until the batteries in the handset went dead. took a long time. Then I just changed the 2 aaa batteries in the handset.
Hope this helps, Stan