Apple Watch vs Garmin battery life: the numbers on the box vs real life

Nightly charging versus weekly, or even monthly. Here's every current model lined up, and how much the marketing figures actually shrink once you use the features you bought the watch for.

The short version

Every Apple Watch needs charging roughly once a day. Every current Garmin lasts at least several days, and some models genuinely stretch to weeks — but only in stripped-back modes most people don't actually use. The real gap is smaller than the marketing numbers suggest, but it's still decisively in Garmin's favour.

Apple Watch battery life, model by model

• Apple Watch SE 3 — up to 18 hours normal use, up to 32 hours in Low Power Mode
• Apple Watch Series 11 — up to 24 hours normal use, up to 38 hours in Low Power Mode, with fast charging delivering 8 hours of use from a 15-minute top-up
• Apple Watch Ultra 3 — up to 42 hours normal use, up to 72 hours in Low Power Mode

Every Apple Watch is designed around a nightly charging habit — even Ultra 3's headline 72-hour figure only applies with most features dialled back, not as a normal daily-use number.

Garmin battery life, model by model

• Garmin Instinct 3 (MIP display) — up to 28 days in smartwatch mode
• Garmin Instinct 3 (AMOLED display) — typically 8-13 days in smartwatch mode
• Garmin Venu 4 — around 11 days in smartwatch mode
• Garmin Fenix 8 — up to 16 days in smartwatch mode, varying by size and case material

Fast charging: Apple's consolation prize

Apple Watch Series 11 and SE 3 both support fast charging, recovering hours of use from a short top-up — useful if you forgot to charge overnight and need enough juice to get through a workout. Garmin's charging is typically slower in absolute terms, but matters far less in practice because you're doing it so infrequently.

What actually drains each watch fastest

• Always-on display — the single biggest drain on both platforms. Turning it off roughly doubles battery life on most models.
• Continuous GPS tracking — the biggest drain during actual workouts, especially multi-band/dual-frequency modes that trade battery for accuracy.
• Cellular connectivity (Apple Watch GPS+Cellular models) — noticeably shortens battery life versus GPS-only when actively used away from your iPhone.
• Notifications and background sync — a smaller but real drain on both, more noticeable on Apple Watch given its heavier smartwatch feature set.

The verdict

If nightly charging genuinely bothers you, or you need a watch that survives multi-day hikes, ultras or travel without a charger — Garmin wins outright, and it isn't close. If you're an iPhone owner who's fine plugging in every night in exchange for the best software experience and deepest iPhone integration — the Apple Watch's battery life is a non-issue in practice, since charging becomes routine within a week of ownership.