2025 Buying Guide – External Batteries & Powerbanks

Everything you need to know to choose the right external battery : capacity (mAh → Wh), USB-C Power Delivery , Qi2/MagSafe , iPhone/Samsung compatibility (PPS), airplane rules, safety and maintenance.

1) How to choose your power bank in 2025

  1. Capacity (mAh) → battery life. Aim for 10,000–20,000 mAh for 1–3 smartphone charges; 30,000 mAh for long days.
  2. Power (W) → speed. 20–30W is sufficient for phones; 45–65W for USB-C PD-enabled tablets/ultrabooks.
  3. Technology : Qi2/MagSafe if you want magnetic (iPhone), wired USB-C PD for universal efficiency.
  4. Ports & functions : USB-C (IN/OUT), multi-ports, pass-through, display %, integrated cable, PPS (Samsung).
  5. Weight/size : slim for pocket; robust/waterproof for outdoor use.

Tip: Always pair a USB-C charger/cable adapted to reach full speed.

2) Capacity: understand mAh ⇄ Wh

Formula: Wh = (mAh × 3.7) / 1000. Wh is the unit used by aviation and reflects the stored energy.

Capacity (mAh) Approx. energy (Wh) Smartphone recharges (≈ 4,000 mAh) Typical use
10,000 ≈ 37 Wh ≈ 1–2 Urban Day
20,000 ≈ 74 Wh ≈ 2–3 Weekend
30,000 ≈ 111 Wh ≈ 3–5 Travel/long journey

Useful capacity depends on losses (efficiency). Expect ~70–85% of theoretical capacity in actual use.

👉 See our Powerbanks by capacity.

3) Power (W) & USB-C PD / PPS standards

  • USB-C Power Delivery is the universal standard for fast charging. PD revision 3.1 (EPR) goes up to 240W over USB-C (5A E-marker cable). Smartphones: typically 20–65W. :contentReference[oaicite:4]{index=4}
  • PPS (Programmable Power Supply) finely adjusts voltage/current (useful on several Galaxy up to 45W with 5A charger/cable). :contentReference[oaicite:5]{index=5}
  • To benefit from full speed, you need: compatible device + suitable charger + 5A cable (E-marker) if > 60–100 W.

👉 Browse our USB-C Chargers & Cables.

4) Wireless: Qi2 / MagSafe (magnetic)

Qi2 brings MagSafe-like magnetic alignment and charges up to 15W on compatible devices. 25W Qi2 is coming gradually in 2025 (certifications pending). :contentReference[oaicite:6]{index=6}

Choose Qi2 if you want magnetic simplicity (iPhone 15–17 & co). For maximum efficiency or tablets/ultrabooks, stick with wired USB-C PD.

👉 Discover our Qi2 / magnetic Powerbanks .

5) Airplane & travel: what you need to know

  • In the cabin only , never in the hold. :contentReference[oaicite:7]{index=7}
  • < 100 Wh : generally allowed without approval. 101–160 Wh : company approval (often max 2). > 160 Wh : prohibited. :contentReference[oaicite:8]{index=8}
  • Many airlines advise against or prohibit in-flight use/charging (plugging a cable into the power bank). Always check your airline's policy before departure. :contentReference[oaicite:9]{index=9}

👉 Prefer a power bank <100 Wh (e.g. 20,000 mAh ≈ 74 Wh). Memo: Wh = (mAh × 3.7) / 1000 .

6) Recommendations by use

iPhone (mobility / MagSafe)

• 10,000 mAh Qi2 (up to 15 W) for the day. • 20,000 mAh if you want 2–3 charges or long filming.

See: Qi2 Powerbanks

Samsung / Android (PPS)

• 20–45 W PD/PPS to take advantage of fast charging (up to 45 W depending on model). • 5A cable recommended. :contentReference[oaicite:10]{index=10}

See: Chargers & Cables

Travel & Airplane

• <100 Wh (e.g. 10–20k mAh) for onboarding without approval. • Consider pass-through and % display.

See: Powerbanks

Outdoor / hiking / van

• Solar for slow charging off-plug. • For lighting or an AC device, think Power Station .

See: Solar Powerbanks

7) Security, compliance & best practices

  • Favors compliant products ( UN 38.3 tests for lithium batteries during transport) and avoids dubious brands. :contentReference[oaicite:11]{index=11}
  • Store away from heat, avoid shocks, and do not cover a charging power bank.
  • For loads >60–100W, use certified 5A E-marker cables .
  • Recharge periodically if you are not using the power bank (e.g. 50–60% every 2–3 months).

Useful links LymobileShop

FAQ – Powerbanks 2025

mAh vs Wh: What's the difference?
mAh = nominal capacity; Wh = energy (aircraft standard). Wh = (mAh × 3.7) / 1000 .
20 W, 30 W, 45 W, 65 W… which power should you choose?
20–30 W = smartphones; 45–65 W = USB-C PD-enabled tablets/ultrabooks. For recent Samsung, aim for PD/PPS (up to 45 W depending on model). :contentReference[oaicite:12]{index=12}
Is Qi2/MagSafe as fast as wired?
Qi2 wireless brings magnetic alignment and up to 15W (25W in deployment in 2025). Wired remains more efficient for high power. :contentReference[oaicite:13]{index=13}
Can I take a power bank on a plane?
Yes, in the cabin only. <100 Wh: OK without approval; 101–160 Wh: approval required; >160 Wh: prohibited. Some airlines restrict in-flight use. :contentReference[oaicite:14]{index=14}