Long ride battery test

Over the weekend, I completed a ride I used to do annually but had missed since COVID.  It is a 77-mile/124 km+ (1000m elevation) circular ride around London parks, paths, trails, and alleys, closely based on the pedestrian Capital Ring route where permitted. Unusually, I did it with quite a large group this time, so, factoring in sheared hangers, punctures, extended meal and coffee stops, closures, plus a close-to-home outdoor bee, this took 12 hours door-to-door. It’s about a 7.5-hour ride on a trail bike, normally, if you don’t get lost or have any mishaps.

The ride is a testament to modern navigation tech, where it’s hard to get seriously lost. When I first did the ride many moons ago, unfamiliarity with the route and only a breadcrumb trail to follow meant I never finished and got lost on a canal towpath somewhere near Southall.

Ride with GPS route file: here.

Battery Test Results

Battery levels were all 100% charged at the start, and the 12-hour ride was continuously recorded even at stops. Here’s what was left in the tank.

• Garmin Forerunner 970 – 60% (30-hour battery life – claimed 30 hours)
• Apple Watch Ultra 3 – 13% (13 hour 47 minute life – claimed 14 hours. 100% health)
• Wahoo Elemnt Roam 3 (active navigation) – 45% (21 hours 49 minutes life – claimed 25 hours)

All three devices have had good use over the last year, with the Apple and garmin having extensive use and going through very many charge cycles. Less so with the Roam, as I swap my bike computers a lot.

Two take outs

This is a quirky, interesting and fairly challenging ride. A great way to see the backstreets of London in a way that very few others will do each year. Avoid the pedestrian-only sections and stop to enjoy some of the views on the hilltops.

When it comes to battery life, this test reinforces the view that manufacturers often make accurate claims using fairly realistic usage scenarios. In fact, they tend to slightly understate the battery life you will get on a new device before its battery performance starts to degrade with repeated charge cycles. I was surprised that my Apple Watch battery health was still 100% after  6 months, probably because I have been using smart charging  (Optimised Battery Charging and Optimised Charge Limit). Also, compared to the Apple Watch 11, the Watch Ultra 3 probably goes through 50% fewer charge cycles, hence retaining Health for longer.

How accurate are manufacturer battery life claims for GPS sports watches?

Based on a 12-hour continuous ride test, the Garmin Forerunner 970 matched its claimed 30-hour battery life exactly, the Apple Watch Ultra 3 came within 13 minutes of its claimed 14-hour continuous GPS figure, and the Wahoo Elemnt Roam 3 delivered 21 hours 49 minutes against a 25-hour claim. Manufacturer claims have become significantly more accurate and in some cases slightly conservative for new devices before battery degradation from charge cycles sets in.

Does Optimised Battery Charging preserve Apple Watch battery health over time?

Yes. After six months of heavy use including very many charge cycles, the Apple Watch Ultra 3 in this test retained 100% battery health, attributed to consistent use of both Optimised Battery Charging and Optimised Charge Limit. These features limit the time the battery spends at 100% charge, which reduces the chemical ageing that degrades lithium-ion cells.

How does Apple Watch Ultra 3 battery life compare to Garmin Forerunner 970 for long rides?

For rides up to approximately 12 hours the Apple Watch Ultra 3 is adequate but leaves very little margin, finishing a 12-hour ride with 13% remaining and a projected total life of 13 hours 47 minutes. The Garmin Forerunner 970 is significantly better suited to long-distance events, finishing the same ride at 60% with a projected life matching its claimed 30 hours.

Last Updated on 30 March 2026 by the5krunner

the5krunner

tfk is the founder and author of the5krunner, an independent endurance sports technology publication. With 20 years of hands-on testing of GPS watches and wearables, and competing in triathlons at an international age-group level, tfk provides in-depth expert analysis of fitness technology for serious athletes and endurance sport competitors.