How to fit a TomTom One replacement battery

Obtaining the new battery

The TomTom One uses a 1350mAh Lithium Polymer battery. You can use slightly less amperage (ie ~1100mAh, or a Lithium Ion battery instead, but considering the price and higher charge capacity (longer life = longer hours of use), you might as well get the longer lasting Li-Poly (Lithium Polymer) battery.

I would recommend only getting batteries specifically noted for use with the TomTom, because the back of the case has a recess which might prevent slightly longer/wider or fatter batteries from being installed. The model I ordered was the CS-TM600SL which is for the TomTom One V1.

In the UK I purchased mine for the reasonable price of around £16 from TomTom Work Online who also supply replacement batteries for other TomTom units, although there are various suppliers of replacement TomTom Batteries in the UK:-

This is the link for the TomTom One Version 1 replacement battery.

For other units check their Tom Tom Accessories section which carries parts for the TomTom GO520/520T, TomTom GO720/GO720T and TomTom One New Edition, although I didn't see any batteries for these other units (which I believe are quite different battery shapes and sizes).

Removing the TomTom back with the correct Security Tool

WARNING: Before you start, make sure you have done the following:-

1. Backed up the contents of your TomTom, i.e. everything on the SDRAM Memory Card.
2. Unplugged any charger unit.
3. Turned off the TomTom unit.
4. Removed the SDRAM memory card from the memory slot so as to prevent any potential damage to the card. Nothing is likely to happen, but better safe than sorry.

The trickiest part of replacing the battery is that TomTom have rather sneakily used special bolts to hold the back onto the TomTom which require a special hexagonal allen key type tool, but they have a central stud which prevents a normal hex allen key tool being inserted.

I suspect this is done so that us average Joe's don't like the look of it, and think "Oooh, that looks a bit tricky, I suppose I had better send it to TomTom (or one of their dealers) to replace the battery and pay them an exhorbitant fee plus postage for the privelege!".

Having said that you might be able to find a local dealer who is willing to replace the battery for you cheaper than the total cost of getting the parts to do the job yourself. Bear in mind that the alternative of sending your TomTom away may involve additional delivery insurance costs!

So unless you have one of these special security tools (or know a friend who does) you will need to order a small toolset at the same time that you order the battery. I found a 33-piece toolset at www.Maplin.co.uk which cost £8.99. I considered this was ok, given that there were a good variety of bits in the set, and these could come in handy in the future, given that more and more products are being fitted with security type bolts.

Maplin part GU60Q 33-piece Security Bit Set

The first step is to remove the four angled rubber grommets protecting the security bolts. This is done by gently prying them out with the tip of a small screwdriver.

Once removed you have access to the security bolts. You have turned off the unit, and removed the SDRAM Memory Card haven't you?

Carefully undo the security bolts using the correct size hexagonal security toolbit. In fact I found very slight differences in the size of the bolt hex opening, which meant I had to use different toolbits for different bolts! Nice quality TomTom (not)!!

Once all four bolts are removed carefully prise the back off. Note from the photo below that there is a fairly short lead on a connector attached to the loudspeaker in the back of the case, so don't rip the back off or you'll damage the lead or connector. While working I simply unclipped the connector so that the whole back could be removed and put aside. Don't worry, the connector can only be inserted one way around due to keying, so it ensures you can only reconnect it the correct way.

Removing the Old and fitting the New Battery

Inside there is some black tape sticking the battery lead to the PCB (printed circuit board). Carefully lift the tape off the board with your fingers (don't use any sharp implement as you could damage the circuit board).

Then gently unclip the battery connector from the socket on the board.

The photo below shows the new battery in place because I took the photo after I had removed the old battery. Anyway, the old battery was stuck down very firmly with a kind of cushioned sticky-pad. This required considerable effort to remove the old battery from the unit, and I had to use a wide-tipped flathead screwdriver blade to gently but firmly prise the battery and sticky-pad up and off the battery mounting pad. Be very careful not to force or break the case or the surrounding components. As the sticky-pad starts to lift and come away it will get easier to lift off, so do it nice and slow and easy.

Once removed, you need to take the double-sided sticky pad off the old battery, and fix it to the backside of the new battery.

Warning: Before you go sticking that new battery back into place, check its positioning very carefully. My new battery was very slightly larger dimensions than the old battery, and it only just fit into place in the recess on the inside face of the case back when the back was replaced (see 2nd pic below). The first time, I just stuck the battery into place without realising, and the back would not seat down properly, so I had to remove and reposition it again.

Do you see how the case back has a battery recess lip? Look just to the right of the circular loudspeaker, and you can see a rectangular lip and then two slightly more raised L-shaped lips. It's the higher raised lips that the battery has to sit between, otherwise the back won't go on properly.

With the battery back into position, you can;

• plug the battery connector back in paying attention to the correct way around,
• re-affix the black tape to hold the lead to the circuit board
• reconnect the loudspeaker connector lead (if you undid it)
• re-insert the SDRAM memory card ready for a quick test

Now, before replacing the back you should try turning on the TomTom. Usually new batteries are only slightly charged (perhaps only 1/8th or 1/4 capacity), so don't expect it to be full, but hopefully there will be enough charge for the TomTom to start up and show that it is working ok.

So that's it. If all is well turn it off again, and put the back into place, being sure that you don't trap any of the wires where they might get squeezed, then fix the back with the bolts, and put the rubber grommets back in their holes.

Put the unit on charge for a couple of hours to bring it back up to full charge.

Dispose of the old battery properly (see the Cautions in the photo of the new battery above).

There you go, TomTom ready to go again.

Now, if you followed my instructions, but for any of the other TomTom models please let me know of any differences or problems you encountered so I can add that information to this page for the benefit of other people. If you have photos that would be good. Thanks, Jim Prior.