Last updated: 21 October 2026
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To charge an iPhone X once you need a power bank of at least about 4,200mAh, and a 10,000mAh power bank gives about two full charges. The iPhone X battery is about 2,716mAh, and roughly 65 percent of a power bank’s rated capacity actually reaches the phone, because some energy is lost as heat. Here is the maths and the power banks we would buy. Ratings were read on Amazon on 21 October 2026.
Quick answer
| Power bank size | iPhone X full charges (about) | Good for |
|---|---|---|
| 5,000mAh | 1 | Emergency top-up |
| 10,000mAh | 2 | A day or two out |
| 20,000mAh | 4 to 5 | A weekend or trip |
The maths
- iPhone X battery: about 2,716mAh.
- Usable power bank capacity: rated mAh times about 0.65.
- Charges: usable capacity divided by 2,716.
Example: 10,000mAh × 0.65 = 6,500mAh, which is 6,500 ÷ 2,716 = about 2.4 charges. Real results vary with cable, temperature and phone use.
What you need besides capacity
- The right cable. The iPhone X uses a Lightning port, so use a good USB-C to Lightning cable for fast charging: Anker USB-C to Lightning cable.
- USB-C Power Delivery. The iPhone X supports fast charging on a USB-C PD port with that cable.
- Size. A 10,000mAh bank is pocket sized. A 20,000mAh bank is heavier.
Picks
INIU 10,000mAh 45W: best for most iPhone X owners
About two charges, and it holds 4.4 stars from about 88,400 ratings. Buy it if you want a daily carry bank. Skip it if you need more than two charges.
Check the price of the INIU 10,000mAh on Amazon →
Anker 10,000mAh PowerIQ: trusted brand
Holds 4.5 stars from about 7,700 ratings, with an 18-month warranty. Buy it if you want a known brand. Skip it if you want 45W.
Check the price of the Anker 10,000mAh on Amazon →
INIU Smallest 20,000mAh: for trips
About four to five charges. It holds 4.6 stars from about 29,400 ratings. Buy it if you travel. Skip it if you want the lightest option.
Check the price of the INIU 20,000mAh on Amazon →
Anker USB-C to Lightning cable
Needed to fast charge an iPhone X from a USB-C power bank. It holds 4.7 stars from about 25,000 ratings.
Check the price of the Anker cable on Amazon →
How we choose
We compared specs, tested-by-others results and real owner feedback. We only included products in stock on Amazon with 4.0 stars or higher and at least 200 ratings, and we describe what owners report rather than claim testing we did not do.
FAQ
How many mAh do I need to charge an iPhone X?
At least about 4,200mAh for one full charge, once losses are counted.
Can a 10,000mAh power bank charge an iPhone X twice?
Yes, about two times.
Does the iPhone X support fast charging?
Yes, with a USB-C Power Delivery source and a USB-C to Lightning cable.
Can I use any power bank?
Yes, with a compatible cable. Avoid damaged or unknown-brand banks.
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