Updated 06/30/2026

The Zero Power is an ultralight, slim power bank with fast charging and efficiency modes, making it a reliable option for hiking, backpacking, and other outdoor adventures where space and weight matter.

I’ve tried a lot of power banks over the years, and the Flextail Zero Power stands out immediately for its weight. At just 5.2 ounces, it’s lighter than any other power bank I’ve carried, with a slim, low-profile shape that fits easily into a pack pocket and doesn’t take up much space alongside other essentials.

Stats

• battery capacity: 10,000mAh
• weight: 5.2 oz (145 g)
• dimensions: 4.8 × 2.3 × 0.4 inches
• ports: 2 × USB-C
• charging modes: Smart Efficiency and Fast Charge
• includes: lanyard/charging cable
• price: $57.99 (use code IHeartPNW15 for 15% off at Flextail)

Features

The Zero Power has two USB-C ports for faster charging and supports both Smart Efficiency and Fast Charge modes, letting you choose between maximizing speed or stretching the battery farther. When Fast Charge is active, it’s noticeably quick. On a recent hike, my phone was down to 3% just as the sun was setting, so I plugged it in and turned on Fast Charging. Within about 15 minutes, my phone was already back up to 55%, which meant I could keep using it — and more importantly, keep taking photos as the sunset colors peaked instead of missing the moment.

For longer days outdoors, the Zero Power has a built-in safeguard that automatically reserves about 10% of the battery, which adds an extra layer of reassurance. Knowing there’s power held back for an emergency call, a quick navigation check, or headlamp use makes a difference when you’re relying on your devices in more remote settings.

The forged carbon fiber shell provides a rigid outer layer that feels more protective than thin plastic housings, helping it hold up to being packed, unpacked, and jostled around on the trail without adding unnecessary weight. I also appreciate that the included lanyard doubles as a USB-C charging cable, which cuts down on extra cords and keeps everything together.

Field Notes

I keep the Zero Power stashed in my hiking essentials ditty bag so I always have a reliable way to keep my devices charged. Its ultralight weight makes it especially useful on backpacking trips, where saving even a few ounces in my pack matters. Beyond its lower weight, this is the power bank I reach for over others I’ve used thanks to its features — the ability to do a fast charge or switch to efficiency mode for longer trips, plus the 10% battery reserve for emergencies.

Since this product is fairly new to the market, I haven’t had a chance to test it over the long term yet. As I use it on more trips, I’ll keep this review updated with notes on overall performance and durability.

Disclosure: this item was donated for the purpose of a review.

Gear Reviews: My goal is to share clear, unbiased information about outdoor gear. I am not sponsored by any gear companies and I don’t accept paid posts or links. I regularly receive products from brands for review, with no expectation of a positive review and no compensation for my opinions. As an independent gear reviewer, I only review items I’ve personally used on multiple trips and that I believe are high-quality and worth recommending.

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