Replacement battery

I have a kickstarter JS2 which hasn’t had much use. I bought it as a possible replacement for my pebbles but as the app wasn’t ready day 1, I kinda parked it. I’ve pulled it out a few times since but never really got to grips with it.
Anyway, I thought I’d try again but the battery life is really poor…it just about manages a day.
I’ve fully charged it a few times, factory reset and tried running with default apps only but no luck so I’m guessing the battery is knackered.
I wouldn’t be keen to try myself, but is there any replacement service?

Hi, sorry to hear you're having troubles with the battery life. We don't offer battery repairs (by the time it's been sent to the UK and we send it back the postage alone is half the cost of a new watch).

However I'd be surprised if the battery was at fault - I've got a ton of original KickStarter devices here and they still work pretty well.

How long are you charging the watch? Because of the way the battery level is reported (by voltage) if you're disconnecting the watch as soon as the battery widget says 100% you won't be charging the battery anywhere near full - I'd just try and leave it on charge over night, and see if that helps at all?

Thanks for the reply Gordon.
I did charge overnight, although I'm not sure if I have done that again since i factory reset so I'll give that a go.
I am in the UK BTW.

I’ve fully charged it a few times, factory reset and tried running with default apps only

also updating to latest firmware may help if you did not do it yet and still have very old firmware version
https://www.espruino.com/Firmware+Update#bangle-js-2

Update - left on charge for 12+ hours so fully charged
Was already on latest firmware as suggested by @fanoush
Also disabled flash and removed messages widget as suggested by @WizardStan in other post.
Still only getting 24 hours battery life.

Ok, sorry to hear that - that is a strange one then.

So if you do a factory reset and just leave the watch as it is, not connected to your phone or anything, you're still only getting 24 hours out of it?

Not quite, as I did connect it to my phone.
I'll try again without connecting to anything and see if it's any different and report back.

Update - factory reset watch and fully charged. Not connected to anything, just turned on and left it… lasted approximately 26 hours before powering off so seems I’ve definitely got an issue with the battery. @Gordon

Thanks for checking on that. That's not a good sign then - it sounds like a battery issue as you say. I haven't really come across this before, but maybe being left to run flat for those ~3 years did cause the battery issues.

You could try leaving it on charge for several days, just in case there's a chance it'll recover a bit more?

Update! That seems to have worked.
Left on charge for 4 days (2 days turned off,then 2 turned on).
Took off charge Saturday morning and set up and been using since….60 hours in and battery still at 85%.

That's brilliant - really good to hear!