The Ultimate Guide to Choosing a Mobile Battery | Recommended Rankings by Performance

Exiting without charging your smartphone, tablet, or laptop can be troublesome. Many manufacturers such as CIO, Anker, Elecom, and UGREEN offer various mobile batteries with differing capacities, charging speeds, and features, which can make choosing the right one confusing.

In this article, we carefully select 49 products, focusing on bestsellers from major EC sites like Amazon, Rakuten, and Yahoo! Shopping, including the latest models from popular brands. We conduct real-world tests from five perspectives: actual capacity efficiency, portability, smartphone charging speed, device charging speed, and wireless charging speed. Along with key selection points, we introduce scene-specific recommended mobile batteries. Use this as a reference for your purchase.

Truth Behind 49 Bestselling Mobile Batteries Based on Actual Test Results

To find the optimal mobile battery, we comprehensively cover new products from popular brands and top-ranking items on each EC site, thoroughly testing in the following five categories:

Test Items

• Actual Capacity Efficiency: The ratio of usable capacity to the labeled capacity
• Portability: Ease of carrying based on thickness and surface area
• Smartphone Charging Performance: Maximum output value measured
• Device Charging Speed: Maximum input value measured
• Wireless Charging Functionality: Supported standards and actual output

Balancing Charging Power and Size｜Introducing models prioritized for fast smartphone charging, from high-speed to compact

【Top Tier】SMARTCOBY Pro SLIM CABLE (CIO)

Score: 4.6 / Cheapest: ¥5,980 (as of 2026/01/08)

Convenience with built-in cable. Ultra-slim yet high capacity option

The “SMARTCOBY Pro SLIM CABLE” from CIO is a next-generation mobile battery that achieves substantial capacity despite its ultra-thin design. The USB Type-C cable is integrated, eliminating the need to carry a separate cable, minimizing luggage. Available in black and white, with a 1-year warranty and battery recycling program.

Measured capacity shows 75.98% of the labeled capacity, recording a high efficiency level compared to industry standards. The actual usable power closely matches the labeled value, ensuring reliable performance for the expected number of charges.

Portability Verification

Only 1.8cm thick with a surface area of 63.77cm². It feels natural alongside a smartphone and easily fits in pockets or bags without stress—its greatest strength.

Fast Charging Capability

Maximum output of 39W confirmed in tests. It quickly charges smartphones and tablets, making it effective even during short travel times. Input to the device reaches up to 35W, allowing quick recharge overnight or before heading out.

User Evaluation Highlights

• Minimal discrepancy between labeled and actual capacity
• Industry-leading thinness at 1.8cm
• Rapidly restores smartphone power with 39W output
• 35W device charging shortens morning prep time
• No notable flaws

【Next Best】SMARTCOBY TRIO (CIO)

Score: 4.59 / Cheapest: ¥6,970 (as of 2026/01/08)

Three ports simultaneously charging. Versatile enough for smartphones and laptops

CIO’s “SMARTCOBY TRIO” is a compact model with a large 20,000mAh capacity and high 67W power delivery, roughly the size of a credit card. Equipped with two USB Type-C ports and one USB-A port, it supports simultaneous charging of multiple devices like smartphones, laptops, and earphones.

Capacity verification shows 75.23%, with minimal deviation from the labeled value, enabling planned multiple charges without worry.

Size and Portability

At 3.0cm thick, slightly bulkier but still within the size of a card (65.68cm²). Fits well in bags or pockets, easy to grab during desk work or on the move.

Output Performance and Practicality

Maximum 71W output efficiently restores smartphones quickly. Ideal for busy mornings or rapid charging during travel. Input up to 67W allows quick recharging, even if forgotten overnight.

User Evaluation Highlights

• High proximity to labeled capacity
• Excellent balance of compactness and large capacity
• 71W output for fast smartphone charging
• 67W input for quick device recharge
• No notable flaws

【Third Place】SMARTCOBY Pro SLIM (CIO)

Score: 4.54 / Cheapest: ¥4,818 (as of 2026/01/08)

16mm thin. Compact enough to carry daily, surpassing smartphones

CIO’s “SMARTCOBY Pro SLIM” is a standard 10,000mAh model. It features three USB-C ports for multiple device charging and a scratch-resistant textured surface.

At only 16mm thick, comparable to a smartphone. Fits easily in bags or pockets, perfect for daily carry.

Capacity and Actual Measurement

Actual capacity is 69.47%, with some deviation but sufficient for typical daily use. It performs well in everyday scenarios.

Charging Performance

Maximum 38W output supports fast charging for smartphones. Even if you forget to charge beforehand, it can quickly restore power. The maximum input of 35W shortens charging time overnight.

User Evaluation Highlights

• Ultra-thin 16mm design, feels like carrying a smartphone
• Supports quick smartphone charging
• Fast charging for the device itself
• Limited discrepancy between labeled and actual capacity
• No flaws

【Fourth Place】Uno Cable Built-in Mobile Battery (UGREEN)

Score: 4.53 (as of 2025/12/26)

Large capacity in a slim body. Capable of charging 3 devices simultaneously

UGREEN’s “Uno Cable Built-in Mobile Battery” features an integrated USB Type-C cable. Supports simultaneous charging of three devices, with real-time charge status displayed on an LCD.

Actual capacity is 82.26%, one of the industry’s top levels. Minimal deviation from the labeled capacity ensures reliable operation for planned charging cycles.

Portability Focus

2.0cm thick, 80.68cm² surface area. Compact enough to carry with smartphones, fitting easily into pockets or bags—ideal for commuting or daily use.

Charging Speed

Maximum 35W output enables quick charging of smartphones and tablets. With a 30W maximum input, it can be fully recharged during morning routines.

User Evaluation Highlights

• Nearly matching actual and labeled capacity
• Compact size compatible with smartphones
• Supports fast charging at 35W
• 30W input for quick recharging
• No flaws

【Fifth Place】Zolo Power Bank (10000mAh, 30W, MagGo) (Anker)

Score: 4.52 / Cheapest: ¥5,990 (as of 2026/01/08)

Seamless iPhone charging with MagSafe. High actual capacity

Anker’s “Zolo Power Bank” is a next-generation model with wireless charging. Compatible with MagSafe, it magnetically attaches to iPhone for charging, with a silicone surface to prevent scratches.

Actual capacity is 86.69% of the labeled value, high efficiency ensuring the planned number of charges.

Wired vs Wireless Performance

Wired charging maxes at 33W, providing quick power-up. Wireless charging offers 7.5W, slower but convenient. Use wired when speed is needed, wireless for ease.

Portability

Balanced size and thickness—compact enough to carry easily, especially for MagSafe-compatible iPhones. A good choice for users prioritizing both capacity and convenience.

User Evaluation Highlights

• High efficiency at 86.69%
• Compact and portable
• 33W wired charging for quick power-up
• 20W input for fast recharging
• Wireless speed could improve

【Sixth Place】ELECOM Power Bank EC-C44LBK

Score: 4.51 / Cheapest: ¥6,999 (as of 2026/01/08)

High capacity, quick charging for smartphones and laptops

Elecom’s “EC-C44LBK” features two USB-C ports and one Type-A port, with a digital display showing remaining power. Supports a wide range of devices from smartphones to laptops.

Actual capacity is 78.20%, with minimal deviation from the label, ensuring reliable operation.

Charging Performance

Maximum 67W output supports fast charging for smartphones and laptops. Ideal for urgent device recovery on the go. With a 67W maximum input, it can be fully recharged overnight even if forgotten.

Size and Portability

3.1cm thick, 78.00cm² surface area. Practical for bags and pockets, suitable for daily use.

User Evaluation Highlights

• High actual capacity ratio
• 67W fast charging for devices
• 67W input for quick recharge
• No flaws

【Seventh Place】SMARTCOBY Ex03 SLIM PLUG ＆ CABLE (CIO)

Score: 4.48 / Cheapest: ¥5,780 (as of 2026/01/08)

Acts as a charger, power bank, and AC adapter. Three-in-one multifunctionality

“SMARTCOBY Ex03 SLIM PLUG ＆ CABLE” is CIO’s flagship multi-function model. It features an integrated USB-C cable and a foldable AC plug. Supports pass-through charging for simultaneous device and power bank charging.

Capacity is 82.28%, with minimal deviation from the label, allowing planned multiple device charges. Reduces worry about battery level, providing peace of mind during outings.

Slim Design

2.2cm thick, 73.21cm² surface area. Easy to store in bags or pockets, perfect for commuting, travel, and daily use.

Charging Power

Maximum 36W output for quick smartphone charging. Fast charging the device itself is also possible, ready for sudden outings.

User Evaluation Highlights

• High efficiency close to labeled capacity
• Slim profile for easy carrying
• Supports 36W fast charging
• Fast recharging of the power bank
• No flaws