Take a reliable land line phone with answering machine.
Graft on a nest and robot for your cell phone.
At night when you drop keys and wallet and start the make dinner, the cell phone ends up in this nest by habit. If left alone a while, the land line phone mates with the cell phone, replaces
the battery "a" with a newly recharged one "b", downloads any messages or changes to phone numbers, maybe even uploads messages the land line got during the day.
In the morning you grab cell phone, keys, wallet and out the door. Land line has all day to recharge the cells battery "a" and get ready to switch it back.