After much searching I’ve come to the following conclusions :-

1. spare batteries for the gen 1 46mm do not exist anywhere.

2. spare batteries for the gen 2 41mm also do not exist anywhere.

3. spare batteries for the gen 2 45mm are plentiful on eBay and AliExpress. Code is GB-S10-432830-020H

4. spare batteries for the gen 3 no longer available. Used to be on AliExpress code 1ICP5/25/26

if anyone can prove me wrong and know a source I will be very glad to know,
Tag seem to want special non standard batteries just for them which makes longevity futile.

 

I was reading somewhere that all Smartwatch going forward from E4 will be able to have battery replaced to prolong usability.
I will try and find it again.

 

https://www.wired.com/story/tag-heuer-connected-45-and-42-smartwatch-2022/

"Like Apple (and unlike most other smartwatch rivals), Tag Heuer is introducing a battery replacement service—available at any of its retail stores. The service is offered for Connected models released from 2020 and will be available for five years after the launch date. The replacement will be a like-for-like swap, rather than an upgrade. Tag Heuer plans to offer this service for every generation in the future."

 

That’s very interesting and a good idea. Why can they not create a battery compartment like old phones and indeed even old smart watches

 

Or tell TH after 23 months that the battery drains in 40 minutes....

 

Are the GB-S10-432830-020H battery connectors directly compatible with the CM45 or do they require modification/resoldering?

 

It’s a one for one exchange. No mods needed. Take old one out put new one in. I’ve already tried it

 

Thanks for confirming and providing the specific model number My CM45 battery is still fine, but I might pick up a battery to hold in reserve.

Do you have any tips for disassembly?

 

Is there a DIY on how to change the battery on the 45 Modular?

 

See VRMAN very good post here :
https://tagheuerforums.com/threads/...n-connected-models.119389/page-2#post-1796095
dated JUL 1

 

Excellent - thankyou!

 

So just to clarify, if I was to purchase a new E3 today direct off Tag website, would I get the exchange battery offer for 5 years from today’s date, or would it be from E3 launch date 2020, just leaving me with 3 year exchange. Thanks.

 

Pretty sure it's going to be from the original launch, based on the wording.

 

Thanks

 

I’m not so sure, it states a battery replacement service, but I agree why mention a like for like swap. Also at least for the E3 , it is not a simple job removing the battery. I’m wondering if the case/screen remains the same but the processor board with the attached battery is replaced, which would be slightly easier for a shop to do. I say this as they normally glue the battery to the back of the processor board. However this would mean you lose all your faces and settings etc with a change. To be honest I have a gen 1 and a gen 2 , I have not noticed a capacity drop in either, I make sure they have charge in them at all times to avoided the dreaded battery shut down.

 

I'd kill for a DIY internal upgrade on the Modular 45 - even if it was just RAM (that part isn't modular, unfortunately!). That extra 512MB RAM in the 41 just makes it feel a lot smoother/snappier in general use - likely due to the incremental bloat of WearOS upgrades. It's a real shame that these premium smartwatches (even the E3/E4) aren't really premium under the hood.

Definitely worth charging them occasionally - even if you just turn them off again, or leave them in cinema+airplane mode, to slowly discharge.