[Seeker]

Anyone tried it? I have a couple of Braun/Oral B toothbrushes the older one is NiCd but the newer one (which is at least 8 years old) takes a NiMH (nickel metal hydride). This is the one I changed.

On my older one, you could use the charger base to unlock/remove the t/brush base and the guts would slide out the bottom. They changed that and I spent a while trying to unlock the base only to discover that the guts now come out the top. Once I realised, it still took a while to separate the bits.

The battery is soldered in, desoldering the neg terminal was fairly easy. There was less copper pcb track at the positive end and you also had to desolder the 2 motor contacts. Assuming all the leads were now free, you had to pry the pcb near the switch and lever it along its length until it pops out, taking the charging coil with it. The pcb is only 15 mm wide and flexes alarmingly before being released. Finally the battery is revealed.

Next issue was the replacement battery leads were much wider than the original and I had to use my best nail scissors to trim them down.

Once everything was back in position and resoldered, I tried turning the toohtbrush on and... nothing. Measuring the battery voltage seemed to show it to be similar to battery that came out so I assumed I'd broken something. I checked the pcb tracks for any inadvertent bridges but all seemed good, so I put it on the charger without the case for 20 mins and after that it started to run.

Refitting it into the case was another minor obstacle - the old t/brushes would slide in and lock with a twist, this one required you to get the "in use" alignment and then push it against a spring until it clicks.


My toothbrush looks decidedly bashed around now so I hope this was worth it. The battery instructions said to charge it for 24 hours, so we'll see.