Portable chargers are a category full of dishonest products. The capacity claims are often false (manufacturers rate batteries at different voltages than your devices use, inflating apparent mAh). Build quality varies from "fine" to "fire hazard." The brands that consistently deliver what they promise: Anker, Mophie, and Belkin. Everything on this list is from one of those three, or has been independently tested to verify capacity claims.
Best overall: Anker 737 Power Bank (24,000mAh)
The Anker 737 is the portable charger to buy if you travel and need serious capacity. 24,000mAh real-world capacity (enough for 4–5 phone charges), 140W two-way fast charging (charges laptops as well as phones), three ports (two USB-C, one USB-A), and a smart digital display showing wattage output and exact percentage remaining. It's $60 — the right price for what it does. It's also TSA carry-on compliant.
Best slim/everyday: Anker 622 Magnetic Battery (MagSafe)
The Anker 622 MagSafe is for iPhone 12+ users who want something they don't have to think about. It sticks magnetically to the back of the phone (no cable), charges wirelessly, and is thin enough to carry in a pocket. 5,000mAh gives you roughly one phone charge. It's not for heavy power users — it's for "I forgot to charge overnight and need to survive until lunch." At $40, it's the cleanest solution to the everyday dead phone problem.
Best for travel: Mophie Powerstation PD XL (10,000mAh)
Mophie makes the power banks that Apple sells in Apple Stores — the brand sets a quality bar that most competitors don't meet. The Powerstation PD XL is 10,000mAh, USB-C with 30W Power Delivery (fast charges iPhones and newer Android), USB-A for secondary devices, and has a soft-touch fabric exterior that doesn't look like a tech gadget. Slim enough for a jacket pocket, enough capacity for 2.5 phone charges.
Best budget ($20–30): Anker 313 Power Bank (10,000mAh)
If you just need a portable charger that works without drama, the Anker 313 is $22, 10,000mAh real capacity, and reliable. It only has 12W output (no fast charging), but it will charge your phone 2–2.5 times and Anker's build quality is consistent. For occasional use, road trips, or a kid's first power bank, this is the right answer at the right price.
What the capacity numbers actually mean
Portable charger capacity (mAh) doesn't translate directly to phone charges because of conversion losses. A rough real-world guide:
- 5,000mAh → ~1 iPhone charge, 0.8 Android charge
- 10,000mAh → ~2.5 iPhone charges, 2 Android charges
- 20,000mAh → ~5 iPhone charges, enough for a laptop top-up
Buy 10,000mAh for regular daily carry. Buy 20,000mAh+ if you're traveling without reliable charging access for more than a day.
Frequently asked questions
Can you bring a portable charger on a plane?
Yes, in carry-on only (not checked baggage). TSA allows power banks up to 100Wh in carry-on. Most 20,000mAh banks are just under this limit — check the watt-hour rating (usually printed on the device) before flying.
How long do portable chargers last?
Lithium-ion batteries degrade with charge cycles. Expect 300–500 full cycles before significant capacity loss, which is 3–5 years of regular use. Premium brands (Anker, Mophie, Belkin) maintain capacity better than generic brands.
What wattage do I need for fast charging?
iPhone: 20W or higher. Android varies — check your phone's spec. For laptops: 45–65W minimum. The Anker 737 (140W) handles all of these.