The portable power bank review built around the two variables that the review site glosses over: the aviation regulations (the lithium battery capacity limit of 100Wh for carry-on (no exceptions) and the 160Wh maximum with airline approval — the power bank that is over 100Wh goes in the hold, not the carry-on, and if the hold, not on the long-haul flight because the hold is not pressurised for lithium batteries on some aircraft) and the laptop charging reality (the 20,000mAh / 74Wh power bank at 65W USB-C charges the M2 MacBook Air from flat to 60% — the laptop charge that the 14-hour Heathrow-Singapore flight requires to prevent the battery-dead arrival).
Reading time: 5 minutes | Last updated: 2026
The Aviation Regulation
The IATA (International Air Transport Association) lithium battery regulations:
- Under 100Wh: Carry-on permitted on all flights. No airline approval required.
- 100-160Wh: Carry-on permitted with airline approval (contact the airline 48 hours before travel).
- Over 160Wh: Not permitted on passenger aircraft.
The Wh calculation: The mAh rating × the voltage ÷ 1,000 = Wh. A 20,000mAh / 3.7V power bank: 20,000 × 3.7 / 1,000 = 74Wh. Under 100Wh; carry-on confirmed.
The 26,800mAh / 3.7V: 26,800 × 3.7 / 1,000 = 99.16Wh. Under 100Wh by 0.84Wh — technically compliant but the security agent’s Wh estimate may differ. Carry the Wh figure written on the device’s label, not the mAh figure.
The Three Power Banks
1. Anker 737 Power Bank (24,000mAh, 87Wh) — The BGGD Choice
Capacity: 24,000mAh / 87Wh.
The USB-C output: 140W maximum on the single port (the highest USB-C output of any power bank under 100Wh). The MacBook Air M2 from flat to 80% in approximately 70 minutes at 140W.
The simultaneous charging: The 140W is shared across the ports when multiple devices are charging — the laptop (65W) + the phone (20W) = 85W total, within the 140W ceiling, both charging simultaneously at their optimal speeds.
The aviation compliance: 87Wh — carry-on permitted on all airlines without approval. The Anker 737’s Wh rating is printed on the exterior label.
Weight: 693g. Size: 17.8cm × 7.6cm × 3.8cm.
Price: £90-120.
2. Baseus Blade Power Bank (20,000mAh, 74Wh, 65W)
Capacity: 20,000mAh / 74Wh.
The specific design: The ultra-thin profile (1.3cm deep — the power bank that fits in the laptop bag’s rear sleeve alongside the laptop): the Baseus Blade’s form factor is the specific advantage for the traveller who carries the power bank in the same compartment as the laptop.
The output: 65W USB-C — charges the MacBook Air at the correct speed (not the 140W of the Anker 737, but 65W is the MacBook Air’s maximum intake and gives the same result).
Aviation compliance: 74Wh — carry-on confirmed.
Weight: 420g.
Price: £50-70.
3. Mophie Powerstation XXL (20,000mAh, 74Wh)
Capacity: 20,000mAh / 74Wh.
The Apple ecosystem advantage: The Mophie is the power bank that Apple Stores stock and that the Apple-ecosystem user finds the most integrated — the USB-C and Lightning ports, the Qi wireless charging pad on the rear (the iPhone 15 charging wirelessly from the Mophie surface without the cable).
The output: 45W USB-C — sufficient for the MacBook Air maintenance charging (keeping the battery stable under load, not fast charging from flat).
Aviation compliance: 74Wh — carry-on confirmed.
Weight: 354g.
Price: £60-80.
The Real-World Laptop Charge Calculation
A 20,000mAh / 74Wh power bank charging the M2 MacBook Air (the 52.6Wh battery):
74Wh (power bank) × 85% efficiency = 62.9Wh available output. The MacBook Air 52.6Wh battery charged to 80%: 42.1Wh required. Result: one full charge to 80% with approximately 20Wh remaining for phone charges.
The long-haul flight use case: the 13-hour Heathrow-Singapore flight. The MacBook Air battery lasts approximately 10-12 hours on video playback. The 20,000mAh power bank gives one additional 80% charge — the 20-22 hours of combined battery and power bank use covers the 13-hour flight with reserve.
