Braun Oral-B Triumph Professional Care v1 Battery Replacement

This guide will take you step by step through how to open up and dismantle the Braun Oral-B Triumph Professional Care v1 electric toothbrush then repair it by replacing the internal rechargeable battery.

There are two versions of the Braun Oral-B Triumph toothbrushes, the v1 and the v2. The v1 Triumph models have an LCD screen built in to the handle showing battery state and other information as seen on the left in the photo below. The v2 Triumph models have no screen built in but instead have coloured lights as shown on the right in the photo below. Click the photo to enlarge it:


You can also check the type number marked on the bottom of the handle:

  • Type numbers 3731, 3738 and 3745 are v1 models
  • Type numbers 3761, 3762 and 3764 are v2 models

braun-oral-b-triumph-base-type-number-3738 triumph-type-3762-base

Also note the shallow triangular-shaped hole in the base of the v1 Triumph (top) versus the deeper hole in the base of the v2 (bottom).

This tutorial is for replacing the battery in v1 Triumph models. For v2 models the procedure is slightly different so please see our guide to battery replacement for Triumph v2 models instead. For other toothbrush models and type numbers the battery replacement procedure is different again so please see our other guides to toothbrush battery replacement.

The basic method is:

  • Dismantle handle
  • Remove LCD screen
  • De-solder old battery
  • Solder in new battery
  • Re-fit LCD screen
  • Reassemble handle

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



We have also created a short video from this guide to Braun Oral-B Triumph v1 battery replacement on our YouTube channel, which you can also watch below.


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

Tools / Parts / Equipment

  • Braun Oral-B Triumph Professional Care v1 toothbrush
  • Original recharging base
  • Soldering iron: Electronics grade (about 18-25 watt)
  • 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
  • T-6 size Torx (star) screwdriver: Available from
  • Small flat-bladed screwdriver: 2 to 4mm wide
  • Replacement 1.2V NiMH battery. Support us by buying from Either:


To start with, remove any brush heads from the top of the handle and stand the toothbrush, tip downwards, in hot tap water at about 60 degrees C (140 degrees F) for 5 minutes to soften the plastic ring.

Using the screwdriver start to pry off the ring around the shaft. The ring is stepped so you may need to push down into the soft surrounding material to get fully underneath it. Alternatively, you can use pliers to work the ring off using tape inside the jaws to stop them marking the ring.

 braun-oral-b-triumph-type-3738-toothbrush-remove-ring-1 braun-oral-b-triumph-type-3738-toothbrush-remove-ring-2 braun-oral-b-triumph-type-3738-toothbrush-remove-ring-3

Place the bottom of the toothbrush handle on the triangular shaped key on the back of the recharging plug and start to unscrew it by turning the handle anti-clockwise. The base of the handle will start to separate off from the main handle. If the plastic triangular key on your charger is missing or rounded off you can use a screwdriver or ratchet socket with a T-50 size Torx (star shape) bit.

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Keep unscrewing until you can gently pull the base off the handle, exposing the charging coil.


Gently pull the coil out a few millimetres until it clicks.


The two plastic prongs (arrowed below) can be gently squeezed together to release the catches holding the workings of the toothbrush inside the handle casing. Simultaneously squeeze the prongs together and push the metal shaft up from the opposite end into the handle. The innards of the toothbrush should start to slide out. You might find that a little gentle help is needed from the screwdriver to unclip the catches fully.

braun-oral-b-triumph-type-3738-toothbrush-coil-clips braun-oral-b-triumph-type-3738-toothbrush-remove-innards-1 braun-oral-b-triumph-type-3738-toothbrush-remove-innards-2

Fully remove the inner workings of the handle from its casing.


Use the correct T-6 size of Torx (star-shape) screwdriver to remove the retaining screw (arrowed below). These are available from our shopdirect link.

braun-oral-b-triumph-5000-toothbrush-lcd-torx-screw braun-oral-b-triumph-5000-toothbrush-lcd-torx-screw-remove

Gently pry out the clips from both sides of the screen (arrowed below) then lift it up and unhook it from the circuit board.

 braun-oral-b-triumph-5000-toothbrush-lcd-torx-screw-removed braun-oral-b-triumph-5000-toothbrush-lcd-removed

Turn the unit over and gently pry the spring out from between the motor and the battery. It is attached to a plastic spacer and you might find it easier to start at the motor end and pry the spacer out attached to the spring.

 braun-oral-b-triumph-4000-toothbrush-battery-spring braun-oral-b-triumph-4000-toothbrush-battery-spring-removed

This particular toothbrush is fitted with a 42mm long by 17mm diameter battery. Notice how the tag on the positive terminal extends along the space filled by the spring. Some Triumph v1 models are fitted with a longer 49mm battery.


If your battery is 42mm long you might like to replace it with a longer and higher capacity 49mm battery which will run for longer before it needs recharging. This would involve cutting down the spring to make it 7mm shorter. The photo below shows the difference in length of the springs taken from different Triumph v1 models. The longer spring (20mm excluding spacer) is from a Triumph which was fitted with a 42mm long battery. The shorter spring (13mm excluding spacer) is from a Triumph model which was fitted with a 49mm long battery. If you do cut your spring re-fit it with the sharp, cut end against the plastic spacer rather than against the battery.


Time to get your soldering iron warmed up now! Using the soldering iron and desolder pump carefully desolder the battery’s positive and negative terminal solder tags from the circuit board (arrowed below) and bend the metal tags upright and away from the board with a knife so there is no solder left joining the solder tags to the board. Desoldering braid might also be useful for this.

braun-oral-b-triumph-9000-toothbrush-battery-solder-points braun-oral-b-triumph-9000-toothbrush-battery-desoldered

Turn the assembly over and unclip the battery from its holder.


Compare the original battery to its replacement. Please support us with writing these repair guides by buying your replacement battery through the links to our secure online shop. The battery pictured is a 42mm long by 17mm diameter offset tagged battery. However, your toothbrush might be fitted with a 49mm long by 17mm diameter battery. Note how the solder tag on the negative terminal is offset to fit in the channel in the battery holder.

 braun-oral-b-triumph-9000-toothbrush-compare-batteries braun-oral-b-triumph-3738-toothbrush-battery-negative-tags braun-oral-b-triumph-3738-toothbrush-battery-positive-tags

Shape the solder tags on the new battery in the same way as the tags on the original battery. The concertinas give a bit of flexibility in fitting the battery and also help to absorb any vibration but are not strictly necessary. Fold the tags over the tip of the screwdriver to get tight bends.


Using scissors trim the tags to the same length as those on the original battery.

 braun-oral-b-triumph-3738-toothbrush-battery-negative-tag-bend braun-oral-b-triumph-3738-toothbrush-battery-negative-tag-trim

Very carefully start to narrow down the width of the negative terminal solder tag by first snipping into the tag from the left. Careful not to cut right through! Just go a quarter at a time using the tip of the scissor blades. Then cut down from the top to remove the piece.


Do the same at the positive end.


Fit the battery back in its holder, making sure the solder tags go through the holes in the circuit board. You might find it easier to insert the battery at an angle, getting the negative tag through its hole first.

 braun-oral-b-triumph-3738-toothbrush-replaced-battery braun-oral-b-triumph-3738-toothbrush-replaced-battery-pcb-tags

Bend the tags over the edge of their holes and solder them back on to the circuit board. Make sure you get good, shiny solder joints as bad soldering is a common cause of recharging problems.


Re-fit the spring and its insulating spacer between the battery and motor.


Hook the LCD screen back onto the circuit board and clip it into place. You might find that the screen starts to flash.


Secure the screen with its screw.


You can now slide the innards of the toothbrush back inside the handle casing. The charging coil will push back into the end of the assembly. Make sure that neither of the copper wires from the coil is broken as this is a common cause of recharging problems.

 braun-oral-b-triumph-type-3738-toothbrush-remove-innards-2 braun-oral-b-triumph-type-3738-toothbrush-base-removed

Re-fit the base to the handle and screw it in by standing the brush over the triangle on its charging plug and turning clockwise.

 braun-oral-b-triumph-type-3738-toothbrush-base-unscrewed braun-oral-b-triumph-type-3738-toothbrush-open-base-2 braun-oral-b-triumph-type-3738-toothbrush-open-base-1

Test your work by temporarily placing the toothbrush on to recharge and check that the charging indicator lights up.


If all appears well re-fit the plastic ring around the shaft of the toothbrush. You might need to press it on with a little force so using an old toothbrush head, or a 10 or 11mm ring spanner or similar might help.

braun-oral-b-triumph-type-3738-toothbrush-remove-ring-2 braun-oral-b-triumph-type-3738-toothbrush-remove-ring-1

You should now have a fully reassembled Triumph toothbrush! Put the brush on to charge for a full 24 hours before use. Please recycle your old battery either at a local civic amenity or a supermarket collection point.


The built-in battery meter can get confused when the battery inside the toothbrush is replaced and can prematurely show the battery as ’empty’ when it’s not. If the battery meter shows as empty after recharging it and using it a few times then switch on your brush and leave it running constantly until the battery is completely exhausted. Recharge the toothbrush for 24 hours. Then leave it running constantly until the battery is completely exhausted again. This will help to recalibrate the battery meter. The toothbrush should now charge and run correctly and the meter will be more accurate.

Please leave any questions or comments about this guide on our dedicated Triumph v1 blog post.