This Binatone Fusion 5620 phone battery is a 2.4V NiMH Battery Pack and is the exact fit replacement for the Binatone Fusion 5620 corldess phones. This battery repalces the Corun Ni-MH battery AAA550*2. When you have replaced your Binatone Fusion 5620 batteries place the phone on the charging cradle and charge initially for 15 hours.