Battery Replacement Guide for Braun Oral-B Type 4729 Toothbrush - Professional Care

This guide will show you how to dismantle the Braun Oral-B Type 4729 Professional Care electric toothbrush and repair it by replacing the internal Ni-MH rechargeable battery. Two different sizes of battery were fitted to this model so make sure you buy the matching replacement. Links for buying the batteries are below. This tutorial might also applicable to the similar Braun Oral-B Type 3746 toothbrush
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Direct link to the 42mm x 14mm battery:
toothbrushbatt...
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Direct link to the 42mm x 17mm battery:
toothbrushbatt...
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For more detail please read the full in-depth guide with photos on our website at toothbrushbatt... where you will also find guides for other models.
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Buy your replacement toothbrush battery at toothbrushbatt...

[@ionicindustries]

Direct link for buying the 42mm x 14mm battery: toothbrushbattery.com/buy/oral-b-42mm-x-14mm-replacement-toothbrush-battery/? Direct link for buying the 42mm x 17mm battery: toothbrushbattery.com/product-tag/v2-short/?orderby=price-desc&

[@flipper2392]

Thanks very much for this, I suppose it would be too easy just to open a cover and change battery like a tv remote. Well done Braun!

[@graceg751]

Thnanks for the video. I replaced my toothbrush battery.

[@MrPingui56]

wtf why it´s so complicated

[@Lay-Z_]

no repair, only buy !

[@herrunsinn774]

It's because despite the myth that "Germans are efficient", they are not. I've lived in Germany for 3 years and see this brand of efficiency every day. If the Germans can make something needlessly complicate, they will.

[@w.manders2817]

the copper wires are extremely vunerable, be careful!

[@kliklakberlin]

A. No need to unclip the power switch plate, as it can be held up with a screwdriver tip underneath when needed. - B. Battery type needed is 42x14mm 4/5 AAA 1.2V, NiMH such as a PANASONIC HHR-120AA. - C. Battery direction is minus at bottom of toothbrush (as noted) - D. Soldering the minus/bottom side of battery using it's tap can be tricky. I soldered a short wire to the board first, then bent it towards the bottom of the battery, trim cut and soldered it directly to it. That is easier, than using the battery tap, especially, when you soldering tip is too big. - - - Maybe you could supply a list of needed tools, too. In any case THANX MUCH!

[@sannabjorke6342]

Serioulsy!! Why make it easy when you can make it difficult.....

[@herrunsinn774]

It's because despite the myth that "Germans are efficient", they are not. I've lived in Germany for 3 years and see this brand of "efficiency" every day. If the Germans can make something needlessly complicate, they will.

[@Elisah209]

Thanks so much. This is the second time I’ve used this tutorial to replace my battery and it worked. It should become much easier to replace the batteries to provide environmental waste of resources. We owe that to our future generations.

[@michielmos1972]

Great video, helps me to decrease electronic waste. Much appreciated!

[@melvynburchell]

I have just repaired mine and my wife's toothbrushes... I went for the 49mm x 14mm battery (original was 42mm x 14mm) for the extra capacity and hence more uses before charging is necessary - my replacement cells were 2000mah considerably more than the originals... But be warned the extra length does require quite a lot of cutting away of the base plastic (care obviously needed to avoid breaking any of the thin charge coil wires) in order to be able to fit the bottom back on... I also did away with the spring as the base plastic was hard up against the bottom of the battery... I wouldn't say that it is a new lease of life as they are now better than original!

[@zoe-huongtran2109]

I gave up- you won Braun...

[@maurocarimati4230]

grazie mille ottima guida vorrei aggiungere che per aprirlo nel mio caso ho dovuto prima scaldare la base con il phono perche' era indurito dal tempo e non girava

[@abecedariusman]

Ciao, scusa ma che tipo di batteria hai usato? Su quella che ho smontato non c'è scritto nulla e non so le caratteristiche. Grazie se mi vorrai rispondere

[@manunova2609]

unfortunately it didn't worked for me. I have break all plastic because, i guess, my toothbrush is too old (close to 10 years..)

[@stephanelobit]

42x17 does not fit the plastic cover. Better buy a 42x14 as the original.

[@ionicindustries]

Some versions of the 4729 have battery holders that only take 42mm x 14mm batteries. Some have holders that take 17mm diameter batteries and were originally fitted with 42mm x 17mm batteries.

[@Waxcu]

Did this swap, and while the battery wont die mid brushing it didn't bring any of the lost power back. Maybe the motor is shot. TLDR: If your brush feels weak this fix may not help.

[@ionicindustries]

If the motor is running slowly then a drop of light oil on the motor bearings might help. You can also grease the drive mechanism while the handle is open.

[@Waxcu]

@@ionicindustries i did clean and grease the drive while swapping the battery. But that did not feel like it had any effect. How do i get to the motor bearings?

[@ionicindustries]

You might only be able to get near the one nearest the drive mechanism. The bearing is where the metal output shaft of the motor leaves the casing of the motor.

[@tehedx]

Informative, looks doable. Thanks!

[@RandallSchwed]

Up and running now.😁👍

[@spooley1959]

Good instructions. Thank you.

[@LeoSpeed955]

Donne it, thanks

[@Chalkida24]

Epic failure on design!! 🥳🥳🥳

[@TheDjjojo72]

Thanks

[@jgkort]

Ordered a battery from this guy's ebay store last week: quick shipping from UK to mainland EU. Followed these instructions, all in all a bit fidgety, but doable if you take your time. Like others mentioned, the negative terminal is tricky. Just finished up and put the toothbrush on its charger. Green light is happily blinking away :) I do have two questions, though. 1) I found that the order for de-soldering the motor terminals matters: my (25W) soldering iron was struggling when I started with the one closest (1m10s). I did the one furthest away first, then the one closest. Made it much easier. Does the motor itself act as a bit of a heat-sink? 2) What's the reason for attaching the positive terminal first, then the motor terminals and the negative terminal last? I hope anyone can educate me a little, thanks!

[@ionicindustries]

To answer your questions, I'm not sure why your soldering iron was struggling with the first motor terminal. Perhaps the iron tip needed a little solder on the end to help conduct the heat to the joint? The reason for reconnecting the negative battery terminal last is to minimise the chance of shorts during reassembly.

[@jgkort]

@@ionicindustries Thank you for your answers, I appreciate that!

[@murrrr8288]

I accidentally tore off the copper wires in the middle. Can I resolder the copper wires back? Does the order matter?

[@ionicindustries]

Yes the order matters. We have a web page explaining the order of the copper coil wires here: toothbrushbattery.com/blog/are-your-charging-coil-wires-broken/

[@johnbennett9630]

I just did mine with one of your batteries, now it's back together when I try to charge it I get the red light continuously and it never charges. What did I do wrong?

[@ionicindustries]

Hi John, have a look through the troubleshooting tips on our web page, and email us if you have any further issues: toothbrushbattery.com/info/customer-support/

[@JOHNNY-pr9kv]

Thanks!

[@giacomomeacci4025]

Very useful, thanks so much!

[@stivenh5430]

When I charge mine it makes green light for 4/5 seconds and then the green light disappear ( I didn't replace the battery yet) that's a problem for the battery or could be something else?

[@Khabirov88]

Dismantle it again and put it back together carefully making sure everything is in place

[@ionicindustries]

As long as there are no signs of water damage inside the toothbrush it is likely to be a failed battery.

[@ionicindustries]

Top tip: When removing the top ring you can use a flat-bladed screwdriver or pliers with tape inside the jaws to stop them marking the ring.

[@alfredobando]

Ionic In

[@DmitryGrushevoy]

Спасибо за видео! Всё получилось!

[@thaiha277]

Hi, my electric toothbrush dropped in hot water sink for about 10 minutes . Now the problems is : it doesn't work when I click on unless I put in the charger for 1,2 sec . Do you know what problem is that and how to repair it ?Thanks

[@melvynburchell]

Sounds as thought there is water on the PCB inside - probably best to slide the insides out of the casing as per this tutorial... Then make sure the inside is dry (especially the circuit board) - wipe off any obvious water then probably 10 minutes or so with a hair dryer around the circuit board will do the trick & reassemble...

[@thaiha277]

Thank you for your suggestion . I will try !

[@banderilllero]

desoldering and bending up the metal pads at the same time is almost impossible. This step is devastating and leads me to throw away that sh*t..

[@iplugnplay3366]

Use a desolder tool (like solder absorbent or suction device)

[@cheadman1]

Type 3738 oral b Braun battery replacement

[@ionicindustries]

The video for the Type 3738 toothbrush is on KZbin here: kzbin.info/www/bejne/qIjbeYJ3nN58aNk

[@williamriker7637]

Hi, can I replace with Li-on battery?

[@ionicindustries]

No because Li-ion batteries are too high in voltage and require different charging circuitry.