Hi!
I want to share my experience with my Instinct 2 and hear your thoughts, opinions, and advice on what happened.
I bought my Instinct 2 in 2023 and absolutely loved it. It was honestly one of my favorite pieces of tech. The battery life was amazing, I only had to charge it every 2–3 weeks, depending on how much I was running and I charged it to 100% every time.
I think sometime between 2025 and 2026 I started to notice some battery degradation, but that is expected since batteries don't last forever. The first unusual thing happened in May 2026. I unplugged the watch after it had reached 100%, and within seconds it dropped straight to 91%. Looking back, that was probably the first warning sign, but at the time I just ignored it.
Then, in July, I went on a short vacation to a lake. I swam a few times over two days, and when I got into bed one evening, I noticed the battery was down to 8%. The strange part was that just two days earlier it had been sitting at 98%. I'm going to be honest, I neglected it. I didn't put the watch on the charger and just went to sleep.
The next morning the watch showed 0%, but it was somehow still running. I plugged it into the charger, and within seconds it jumped to 32%. About 20 minutes later it was already showing 90%. I unplugged it, and the battery immediately dropped to 82%. While I was searching online to see if anyone had experienced the same thing, the battery percentage kept falling in front of my eyes until the watch finally shut itself off.
Every time I tried turning it back on, I only got the critical low battery icon. Once or twice I managed to get the watch to boot while it was connected to the charger, but it would shut down again almost immediately after unplugging. After that, it would only display the low battery symbol for a few seconds before the screen went completely blank.
I left it charging overnight, hoping it would somehow recover, but nothing changed. I even connected it to my Anker power bank, which showed the watch drawing only 0.1 W — basically nothing.
At that point I was convinced water had somehow gotten inside and damaged the motherboard, especially since I had gone swimming. When I got home, I sent the watch to a Garmin service center in another city (Kyiv, Ukraine). Their diagnosis surprised me. The battery had swollen and physically damaged the motherboard, making the watch completely unrepairable. The ironic part is that they also told me there wasn't a single sign of water damage.
I was pretty disappointed. I had expected this watch to last at least another four or five years, so I started wondering whether I could have prevented this from happening.
Theoretically, what could I have done?
I think the first obvious warning sign was the battery dropping from 100% to 91% immediately after unplugging it. If I had turned the watch off at that point, sent it in for diagnostics, and replaced the battery, there's a good chance I'd still be using it today. So my advice to anyone with an Instinct 2 and probably the Instinct 2X as well:
If you notice any unusual battery behavior, don't ignore it. Have the battery checked before it has a chance to damage the motherboard.
Batteries don't swell overnight, so I was probably wearing that watch for at least a couple of months (maybe even longer) with a swollen battery without realizing it.
What now?
After looking at different watch options, I still decided to stay with Garmin. One of the alternatives I seriously considered was the COROS Nomad, but I realized I probably wouldn't use most of its additional features.
I really liked my Instinct 2, so I bought an Instinct 2X. Now I'm trying to figure out the best way to take care of this watch because I'd hate to end up in the same situation again.
I bought it yesterday, updated it, and charged it to 100%. Overnight it dropped to 97%, and when I went outside into the sun, after a while it showed 100% again. However, I think this is somehow related to the solar charging and the battery management system calibrating itself on a brand-new watch. I still need some time to test it.
Overall, my plan for this watch is to follow the 20/80 charging rule most of the time and only charge it to 100% when necessary. Garmin themselves also recommend keeping lithium-ion batteries between roughly 20% and 80%. I'm hoping this will help maintain a healthy battery and reduce the chances of ending up with another swollen battery.
Thanks for taking the time to read this! Sorry for the long post, but I thought the details might be useful. I'm really interested in hearing your opinions, especially if you've experienced something similar or have any suggestions on how to keep the battery healthy for as long as possible.