720/730 920/930 Battery Replacement Tutorial - Discussion

Your picture could have come from mine (except it didn't)

Can be fixed with epoxy resin glue (Araldite) and a myopic friend (or magnifying glass)

My next issue (already posted) is to figure out how to reassemble the lock strip into the connector with the flex cable as well

Any ideas?
Why not post a picture of what you have got as that would make it far easier to prescribe advice as to a suitable fix - Mike
how to open a tomtom720

about a hour ago I posted asking for info on how to open my 720...I went on to say that I bought this used and the battery was shot going dead within about 10 sec of disconnect from power source...the info you had on here about how to open and get through everything was very helpfull .. I found maybe a better way to get the battery out without any or much trouble...My GF had a one of those scrapbooking machines I bought her last year .. a "crikut" or some spelling like that...anyway it came with a plastic scraper that was soft and had a couple of little metal prying handles....I just used the plastic peice to lift the edge of the battery and then used the prying tool to lift the battery keeping it between the plastic scraper and the battery then there was no way to hurt the board...hope this helps anyone else doing this...tomtom works great now...

Be careful of the lithium battery !!

I was not careful when prying the battery off, and fist saw a puff of smoke - then a Roman candle and then flames.

I blew the flame out and pull the remainder of the battery off with some pliers (was VERY lucky they were handy), and dumped it (glowing redhot) into the sink and drowned it.

Cleaned up my 920, put the battery in - and it works.

Was also lucky the battery was lifted at one end or it would have flamed the hole unit.

BATTERY IS VERY FRAGILE (NOT LIKE CELL PHONE BATTERIES) - BE CAREFUL ! Also did not know how flammable lithium batteries are.
I'd just like to record my personal thanks for these great instructions.

Bought my battery for about $11 on eBay - without tools and I had a Torx set given to me as a Birthday present from a friend.

On removing the battery - as said - it is really difficult, why do they use so much glue!

I started with a small screwdriver and wasn't getting anywhere.

I switched to one of those craft knives. The sort that are a thin blade and retractable. This sort of thing Card Making and Card Craft Supplies - Die-Cut Decoupage and Foiled Card Specialists

I was able to remove the battery in 3-4minutes, sliding the knife in bit by bit, extending the blade as I got under the battery. I actually cut away black aluminum covering the battery but of course the battery is expendable! I had to peal off the remaining black cover from the board

I'd bought some glue for 4dollars - but I was able to place the new battery straight onto the board and the remaining glue was well strong enough to hold the battery - probably because I cut away the black cover and the glue was still there.

Brilliant job and all credit to CANDERSON for his excellent guide. I'd have never attempted this without those instructions - or would have knackered my TomTom!
Reassembling the flex circuit connector!
Does the connector go above or below the lock strip and how does the lock strip locate, push in flat or with a twist down from the unlocked position?
Reassembling the flex circuit connector!
Does the connector go above or below the lock strip and how does the lock strip locate, push in flat or with a twist down from the unlocked position?
By "connector", I assume you mean the exposed copper on the flex circuit. The amber flex circuit can only slide in below the latch (same as it comes out). By "below", I mean closer to the PCB.

The latch is lifted from both ends, and raises up SLIGHTLY to release the flex cable. I think some folks have been trying to pull it full vertical and is how some of the latches have been broken. Once released, the cable can be slid out of the connector. It pulls straight out in the same plane as the surface of the board.
Thank you so much for this set of instructions! Just got done replacing the battery in my 920T in about 15 minutes.

One suggestion for safely getting the old battery un-stuck from the board. I took an old plastic hotel key (old credit card or other plastic card would also work) and cut it in half long-ways. Then just carefully worked it back-and-forth under the battery until I could get to it with my fingers. That was the lengthiest part of the entire operation.

Unit sitting on the charger now - hopefully it'll be all set and ready to go in the morning!

Thanks again!

Not completely related to the battery replacement but :
A friend of mine gave me his 930 because it was dead. read this post and the instruction, got a new battery and it worked ..... only for 10 minutes
The reason why it lastest only 10 minutes it's because the battery is not getting charged by the device (plugged my voltmeter and the voltage goes down slowly)
Any help on this ?

Any help on this ?

Open a separate thread in the TomTom GO 630/720/730/920/930/750 section and tell us what you're trying to charge it with for starters and we'll work from there.
I used a strip of Scotch permanent outdoor mounting tape to hold the replacement battery. It's rated to hold 5 lb, which I hope will be sufficient given that there was probably some residual WD-40 on the PCB following the old battery removal. The tape is around 1/16" thick, so it can easily conform to the somewhat lumpy underside of the battery. Everything went back together without a fight, so having the battery sitting a little bit proud of the PCB didn't seem to cause any fit problems.
Go 730 Battery cable attachment

I finally worked up the courage to replace the battery on my 730. Trying to pry the old battery off the board was quite a challenge. I'm assuming there is a correct way to attach the battery cable to slot which I have yet to discover. The old battery cable had the red wire pointing south. Some pictures on this site have yellow as the first wire. I'm sure damage will be done if the connector is inserted incorrectly or is reversed. Any help with correctly attaching the new battery cable to the motherboard slot will be most appreciated.
If it's a three wire battery (which I think it should be, for a Go730), then the connector on it SHOULD be exactly the same as the one you've just taken out.
Is it not?

The connector should look like the one in picture #6 in the .pdf instructions
It's the white bit (circled).
Re: New Battery attachment

Thanks for your reply. For some reason the cable needed some encouragement to enter the slot. I managed to reassemble the TT correctly. I kept my fingers crossed hoping that the motherboard had not been damaged during the battery removal. I let it charge for two hours and it worked! Thanks for the tutorial.
Great news! Those connectors CAN be quite stiff... They usually have some bumps or ridges in the plastic mouldings to crate a primitive friction lock to stop the plugs falling out.
I would not recommend you touch screen ribbon connector. I have years of experience with automotive connectors and this one is the worst I have come across. If you remove the clip you will find it very very difficult to put back.

The better way is to leave it connected, you can move the screen about to get at the necessary screws.
If the connector does come apart, there is a way out. Push the ribbon home and with assistance glue the ribbon into the connector with fast cure epoxy adhesive.
I have done this it works and I have replaced the battery again without disconnecting the screen.
FWIW, there isn't any reason to remove the clip, just release it. It's really a simple device, but as people without experience on this style of clamping device on a flex cable have been having so much problem, a very careful handling of the flex cable without disconnecting seems to be a better approach for them.

I agree that it might be possible to glue things back together after a break, but the broken bit is what creates the pressure between the bare copper on the flex cable and the contacts inside the connector. I am not sure how to recommend retaining that pressure while doing the glue job. Also, you'd want to do this with the unit live - not fun with things all disassembled - so that you'd know that contact was being made. Once you apply the epoxy, you are committed, and it's a one shot deal.
Agree with canderson. There should be no problem releasing the clip, but It certainly shouldn't be removed
But many people do seem to be a bit heavy handed with it and snap it off. You need a VERY gentle touch with it

It's one of those things that once you've broken it, you realise how you should have dealt with it. :lol:

If you can get away with not removing the flexi cable then by all means don't, but if your battery is as firmly glued down as mine was, you'll need to be able to manhandle the case and PCB for quite a long time, and I wouldn't want the screen dangling on that fragile ribbon cable all that time.
The only thing I can see in this instruction is one serious fault. You suggest using Silicone to stick the battery in place, you need to make it very clear that silicone used to seal worktops or windows will give off acid vapour that will destroy electrical connections. You must only use electrically safe silicone.

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