A:AnswerWhy bother getting a new battery. We just toss the old units and get another. They are pretty inexpensive or watch BB sales. I got one on sale (BB on line) for under $11.00
A:AnswerConnected the wine opener electrodes to the charger electrodes with two alligator clip wires ($3.99/Amazon), the device charged and the cork was removed
A:AnswerBatteries for the 4207 Oster are not listed as a replacement part. Give us a call at (800) 334-0759, and I'll get you back to opening wine again in no time. Thank you!