andycivil's video: How to open a Pulsar Toothbrush and change the battery

If you wanted to open up your Oral-B Pulsar Toothbrush but couldn't see how to do it, I'll show you. Your dentist will probably tell you that when the battery is flat, the bristles are done too, but now you can hack your Pulsar Toothbrush the choice is yours, so you can switch to a fresh battery half way through its life. (Also, a NiMH battery will work, but it won't last as long.) This is an Oral-B pulsar disposable electric toothbrush, an impressive piece of engineering. It comes supplied with a duracell battery; I'm going to show you how to change that. You can't get it out without bending the spring clip too far out of shape. You'll need a screwdriver, a sharp craft knife, a tiny drop of oil, and the ability to memorise the number twelve. This green one is one I peeled the rubber off so you can see what your objective is. Your screwdriver should be this wide, to fit inside this hole correctly. You're pushing the latch inside inwards, and towards the battery, so that it doesn't re-engage when you remove it. You're going to cut a slit in the rubber in exactly the right place. Count down twelve ridges, and make a small slit with the sharp knife. Dip your screwdriver in oil; this helps it slide in, and seals the slit again when you remove it. Push the screwdriver into the slit. Push in, and then towards the battery, you may need to do this action a couple of times. The battery, switch and motor assembly slide out. When you re-insert the battery, the negative goes nearest the motor, or the mechanical switch won't work. Push it back into place, spring clip aligned with the vent hole, until it latches. If the cover ends up half a turn out, unscrew it, click once, and try again.