Sick of charging your smartwatch? The Garmin Instinct 3 Solar has the best battery life on the market and is reduced ahead of Prime Day – 1v1 Video Chat & LIve Streaming & Influencer Subscription

By Nick Harris-Fry

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Sick of charging your smartwatch? The Garmin Instinct 3 Solar has the best battery life on the market and is reduced ahead of Prime Day

Nick Harris-Fry

4 July 2025

Pick up the 50mm Instinct 3 Solar for $399

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(Image credit: Garmin)

I test a lot of smartwatches and sports watches and if there’s one thing I’d improve about almost all of them, it’s the battery life, because who would ever say no to more battery life?

However, one watch that it’s hard to fault on this front is the Garmin Instinct 3, and in particular the 50mm solar model of the watch, which can last indefinitely on a charge in sunny conditions.
That exact model is currently reduced ahead of the Prime Day sales, with the Garmin Instinct 3 Solar 50mm dropping to $399 on Amazon, just a couple of dollars more than the lowest price I’ve ever seen it.

Garmin Instinct 3 Solar: was $449 now $399 at Amazon
The Garmin Instinct 3 Solar offers the most impressive battery life you can find on a smartwatch, lasting indefinitely in sunny conditions, when the solar panels around the watch face will charge it faster than it drains. It’s also a top-notch sports watch with Garmin’s reliable tracking and detailed training analysis, and this deal brings it close to the lowest price it’s ever been.

I tested the 45mm AMOLED version of the Garmin Instinct 3 myself, and even that impressed me with its battery life, lasting a week on a charge when running every day.

The 50mm Instinct 3 Solar model in the sale has a memory-in-pixel display, which boosts battery life, and also has solar panels on the watch face.
Spend three hours a day outside in sunny conditions and these panels will harvest enough energy from the sun for the Instinct 3 Solar to last indefinitely in watch mode.
Even if you fire up the GPS regularly to track outdoor activities, you’ll still get incredible battery life from the Instinct 3 Solar, which offers up to 260 hours of GPS tracking in sunny conditions.
The Instinct 3 Solar doesn’t just offer battery life either. It’s a rugged sports watch tested to military standards that tracks pretty much any kind of activity in great detail, and provides useful training analysis to help you get fitter.
It’s a fairly new watch too, having launched at the start of 2025, so it’s not one I necessarily expected to be in sales already. If you need a watch that can handle some truly epic adventures, this deal is well worth considering.

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Nick Harris-Fry

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Senior Writer

Nick Harris-Fry is an experienced health and fitness journalist, writing professionally since 2012. He spent nine years working on the Coach magazine and website before moving to the fitness team at Tom’s Guide in 2024. Nick is a keen runner and also the founder of YouTube channel The Run Testers, which specialises in reviewing running shoes, watches, headphones and other gear.
Nick ran his first marathon in 2016 after six weeks of training for a magazine feature and subsequently became obsessed with the sport. He now has PBs of 2hr 27min for the marathon and 15min 30sec for 5K, and has run 13 marathons in total, as well as a 50-mile ultramarathon. Nick is also a qualified Run Leader in the UK.
Nick is an established expert in the health and fitness area and along with writing for many publications, including Live Science, Expert Reviews, Wareable, Coach and Get Sweat Go, he has been quoted on The Guardian and The Independent.

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