Dismantling the Oral B Vitality.
Unlike many other models in the Oral B range the vitality's body tapers down to the base. Therefore whilst the other models need the base removing in order to access the battery this model requires the top removing. To do this you will need to grip the plastic spigot that the brush head fits onto and rotate the top anticlockwise. In order to minimise the possibility of damage to the spigot it is best to shape two small pieces of MDF or softwood match its contours, which can then be held in a vice. When rotated the top will be forced out of the body by the oblique angle of the joint.
Step 1: Oral B Vitality - Dismantling.
Once you have loosened the top the brush mechanism can be drawn out from the case. You can then see the battery, which is attached to a circuit board. The three metal tabs which connect the motor and switch to the circuit board have the to be un-soldered in order to remove the board and battery from white plastic inner housing. This can be done with a solder removing tool or de-soldering braid.
Step 2: Oral B Vitality - Removing the Battery.
When the battery and circuit board have been removed from the white plastic inner housing, the battery can be removed from the circuit board by de soldering the tags.
Step 3: Oral B Vitality - Replacing the Battery and Reassembly.
The battery in this model is the same size as a standard AA cell (50mm long x 14mm diameter.) so you have a wide choice of replacement cells. In this case I have used a NiMh cell and soldered copper tags on to it to enable connection to the circuit board.
The board and battery are then relocated in the white plastic inner housing and the connections to the motor re-soldered. The spring is then placed inside the charging coil and the outer case aligned and slid down on to the inverted inner mechanism. Once the top and base are correctly aligned they can be pressed together by hand.