Braun Oral-B Vitality Battery Replacement

This guide will take you step by step through how to dismantle the Braun Oral-B Vitality electric toothbrush and replace the battery. The tutorial is based on the Type 3709 Vitality model. Your brush’s type number is marked on the bottom of the handle.

For other toothbrush models and type numbers the battery replacement procedure is slightly different so please see our other guides to toothbrush battery replacement instead.

The basic method is:

  • Dismantle handle
  • Desolder old battery
  • Remove PCB
  • Replace battery
  • Replace PCB
  • Solder in new battery
  • Reassemble handle

This is documented in detail below along with lots of pictures. Click on any picture to enlarge it.

Braun Oral-B Vitality handle

Video

We have also created a short video from this guide to Braun Oral-B Vitality battery replacement here, which you can watch below.

Disclaimer

Any damage to yourself, your toothbrush or anything else is entirely your responsibility. This guide is for professional, educational purposes only and is offered without guarantee or liability.

Tools / Parts / Equipment

  • Braun Oral-B Vitality toothbrush (Type 3709)
  • Original recharging base
  • Soldering iron: Electronics grade (about 18-25 watts)
  • Solder: Lead-free silver solder is great for this
  • Solder sucker (also known as a desoldering pump) and/or desoldering braid/wick
  • Scissors
  • Craft knife e.g. scalpel, snap-off, retractable or Stanley type
  • Small flat-bladed screwdriver: 2 to 4mm wide
  • Replacement 49mm x 14mm battery with solder tags. Either:

How-To

To start off remove any heads from the brush and insert the top of the handle into the middle hole in the back of the recharging base. If your charger does not have this hole, you can use an old toothbrush head held with grips to open the brush.

 Vitality Toothbrush charging base Vitality handle in base

Carefully twist the handle anti-clockwise. It should start to open up but might be stiff so keep twisting it back and forth. It will only twist about an eighth of a turn and then you can slide out the innards. This is the most difficult step and there is the risk of shearing off a piece of your brush or splitting the charging base so be patient and work it loose little by little.

Vitality handle undone

Now that the handle is open you can wiggle the innards out. The spring might fall out so don’t lose it!

Vitality handle undone Vitality toothbrush innards

Remove the spring from inside the copper coil at the base of the handle and put it somewhere safe.

Vitality toothbrush spring removal

Below is where the negative battery terminal is soldered to the circuit board (arrowed):

Vitality negative battery terminal

Using the soldering iron and the solder sucker, desolder the battery’s metal tag from the circuit board and bend it away from the board with the knife. We’re desoldering this first so that we don’t accidentally short out anything when working at the other end.

Vitality battery terminal desoldered

Moving up to the other end of the circuit board, identify the two motor terminals (arrowed, left) and the positive battery terminal (arrowed, right).

Vitality battery positive terminal

Desolder these three terminals and bend the tabs upright using the knife. You need to remove all the solder from these so that the metal tabs can move back and forth in their holes allowing the circuit board to be removed later. Desoldering braid is ideal for this.

Vitality battery positive terminal desoldered

Gently pry the circuit board up at the power button end so that it pops off its plastic peg and starts to come up off the three terminals you just desoldered.

Vitality toothbrush pcb lifted

Heading back down to the negative terminal end, identify the two black plastic tabs that hold the coil to the white chassis of the handle. There is one on each side. See arrow:

Vitality coil clip

Use the screwdriver to gently pry the clips and then slide the coil and circuit board assembly out.

Vitality charging coil unclipped Vitality toothbrush pcb removed

The battery might or might not come out depending on how well the clip (arrowed) at the positive end is holding it in.

Vitality toothbrush battery clip

Remove the battery from its clip and check its measurements. This Braun Oral-B Vitality toothbrush has a 49mm long by 14mm diameter battery with welded on solder tags. Yours might be either an older NiCd type battery or a newer, higher capacity NiMH battery.

Vitality toothbrush battery removal

Compare your original battery to its replacement. Please support us with writing these repair guides by buying your replacement battery through our secure online shop here at ToothbrushBattery.com.

Vitality new battery comparison

The solder tags on the new battery will need trimming with scissors to a similar length as the old battery. Optionally you can shape the positive tag of the new battery so that it fits in the clip like the old one, though you can skip this if you like and keep it straight. Negative terminals (top) and positive terminals (bottom):

Vitality batteries negative terminals Vitality batteries positive terminals

Test fit the new battery in the chassis of the handle and check that the clip engages with the tag on the positive terminal.

Vitality new battery clip

Once you’re happy enough with the clip, trim the tip of the positive terminal to roughly match the old battery. It needs to fit through the slot in the circuit board and have enough metal poking through to bend over and solder to the board.

Vitality batteries positive terminal cut

Test fit the new battery to the toothbrush circuit board.

Vitality battery on pcb

Once you’re happy with the shape of the tag, clip the battery back into the handle and carefully replace the circuit board and coil assembly so that the motor and battery solder tags poke through the holes in the circuit board.

Vitality toothbrush pcb replaced

Bend the positive battery tag over and solder it onto the circuit board, and also re-solder the motor terminals.

Vitality positive terminal refitted Vitality positive terminal resoldered

Move down to the bottom end of the circuit board and solder the negative tag of the new battery to the circuit board.

Vitality negative terminal resoldered

Replace the spring inside the coil then you’re ready for reassembly!

Vitality battery spring replaced Vitality handle undone Vitality handle in base Braun Oral-B Vitality handle

And that’s it! You now have a fully repaired type 3709 Braun Oral B Vitality toothbrush. You will need to put the toothbrush on charge for 24 hours before use so don’t be surprised if it seems dead after reassembly. Please recycle your old battery either at a local civic facility or a supermarket battery collection point.

Please leave any questions, tips or comments below!

22 thoughts on “Braun Oral-B Vitality Battery Replacement

  1. Thanks I followed instructions and installed the new battery. When I connected the positive terminal to the PCB the motor started working but the on/off switch doesn’t work and it won’t turn-off. Had to disconnect the battery to stop the motor. Any advice?

    1. First off, check that the battery is not connected in reverse (+/-). Some other possibilities:
      The battery tags could be touching something metal such as the motor.
      There could be a stray blob of solder causing a bridge on the PCB.
      It could be the switch. There are two types on the Vitality – they are fitted with either a single electical switch on the PCB or a mechanical switch with two buttons. If yours has the two buttons make sure you’re pressing the correct one to switch it off!
      Other than that, go back and check your soldering and check for short circuits.
      Hope that helps!

    2. Ok So I read a comment above. It appears that I had reversed polarity which causes the motors to spin with inability to switch off.

      I can’t believe Braun didn’t put a simple diode somewhere to avoid the reverse polarity issue. Or a diode rectifier. I expect more for my $25. 😛

      Thanks for your guide.

      I am kicking myself as I threw away a perfectly ok but flat battered Bruan Oral B Triumph (cost me $199!) before I knew about the battery replacement hacks.

  2. I also changed my battery inside the toothbrush. But I cannot start it with button.
    It starts when I touch motor casing and leads on the left side of the PCB. Then it starts to spin and gradually slows down.
    Maybe I burned the element between motor terminals.
    Do you know what that SMD element is?

    1. First check your soldering for short circuits and stray blobs of solder. The component connecting the 2 terminals of the motor is a capacitor. If you think it is damaged you can disconnect it to see if the toothbrush runs without it.

  3. Just done my first battery replacement on 3756 using the longer battery. Had a problem at first when the motor would not stop running. Found I had fitted battery wrong way re polarity !!. Refitted correct way and all is fine and no apparent damage to the other components (phew!). I think this arose because the longer battery looks the same both ways (the shorter battery is very obvious re which way to fit). Next time I marked the battery + & – on the ends and opposite the tabs so they can be seen when assembled. Perhaps this point should be highlighted in your instructions (which are excellent).
    Now for the second 3756 battery replacement.

  4. Hello All –
    Re: Oral B 3709
    Can anybody tell me what the capacity of the original battery is (was!) please? I suspect it was nowhere near the replacement’s 2200mAh.
    Thanks,
    Ian.

    1. Hi Ian, if the original battery was Ni-Cd then it would have been between 600mAh and 1100mAh. If the original was Ni-MH then it would have been up to 1650mAh. You can fit lower- or higher-capacity batteries and they will still run and charge fine. The only thing affected is how long they run for before they need recharging again.

      1. Thanks for that. I suspected that the original was a bit weedy. Ian.

  5. Thanks for a great work description! Battery is now replaced, 3709 reassembled and on charging. The only part I had problems with was the initial opening. Since I did not have the grip hole on any of my charging bases, I used the suggested “old toothbrush head and pliers” method. With this method the insides of the toothbrush came loose and started spinning. I resorted to carefully using the pliers directly on the handle tip, which worked out.

  6. Have not actually put a new battery in yet but the dismantling instructions were brilliant.
    Thanks

  7. Hello to all. Thank you for these precious instructions. I replaced 2 batteries on 2 vitality brushes and both do not work anymore! I put them in charge for a whole day. I tried to replace even their batteries that worked badly but nothing, they are dead! What may have happened? The polarity of the batteries is correct and there is no welding dirt.

    1. Are you able to measure the voltages of the old batteries with a multimeter? Get the brushes running with the old batteries, then try replacing them with the new batteries. We have some troubleshooting tips here.

  8. If the original battery is a NI-CD and you replace it with the NI-MH, will the original charger work with the NI-MH battery or will you need a different base charger?

    1. The original charger will charge the Ni-MH battery. There is no automatic shutoff in the Vitality toothbrush so disconnect your charger after 24 hours to extend the lifespan of the Ni-MH battery. Also have a read of our Ni-Cd to Ni-MH battery upgrade info.

  9. Replaced the battery in my 3709 following the excellent instructions, just a quick tip – if you support the repaired internals on the charge base for an hour or so it will get enough charge to test prior to reassembly into the handle.

  10. Re: My brand new Braun electric toothbrush (purchased October. 2019. Head will not vibrate although stem that holds the head vibrates fine. Help before I throw this out.?

    1. Try a different head or take it back to where you bought it as it will be under guarantee.

  11. Nice detail in instructions, but one question. I have a 42 mm battery length. Can I get a direct replacement battery?–All that I have seen are 49 mm. What extra steps are there to using a 49 mm battery in my device? Thanks Jack

    1. Hi Jack, What is the Type number marked on the handle of your toothbrush?
      42mm long batteries of various diameters are available in our online shop here.

  12. Hi – many thanks for these guides and fast delivery of batteries!

    I successfully replaced the battery on an old Braun 3756, but I had problems with a 3710, which is the new version of the Vitality 3709. The redesigned rubber sleeve around the body hampers the removal of the handle top. After several (gentle) struggles, and as warned, the shaft-top broke! But it did enable me to see that the clips that hold the top into the main handle have been beefed up – there is no real ability to rotate the top out of the clip receptacles. I can send pics if required.

    I’d guess gradual prying at the seams with a wide-but-thin blade would be more successful if the rubber sleeve can be moved out of the way: it is glued on! Or maybe gentle pre-heating per your other guides might help.

    Have you had any success with a 3710?

    Regards, Tony H.

    1. Hi Tony,
      We haven’t looked at the newer Type 3710 Vitality brushes yet but I heard there’s a knack to opening them. I’ve seen a photo of the top cap and it doesn’t twist, it just clips in place. It seems that squeezing the body at the sides might let the top cap unclip so it can be pulled out, perhaps after heating it all in hot water as you suggest. Do email any photos you’re happy to share with everyone to the address on our contact page if you think they’ll help us work out how to open it.

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