Hello and good afternoon to you.
Yes, it seems like the battery has reached the end of its life cycle. Yes, the battery can be replaced, so you do not have to throw your Garmin S1 to the curb just yet. Please note though that replacing the battery is very difficult and will need special tools. You can get a new replacement battery on Amazon for $23.00 + $4.49 shipping. This merchant also offers to replace the battery for you. Read all the bullet points for more information.
If you or someone else you know can replace the battery, then you can get it on eBay for $7.95 + $2.95 shipping.
I am just checking to see if you were able to get the battery issue sorted out..
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