20,000mAh or 30,000mAh: which power bank should you choose?
By Robert PetersonFor one phone and everyday backup, 20,000mAh is a good starting point. Choose 30,000mAh for longer trips, more devices or fewer stops to recharge the power bank.
For an iPhone 16 or 16 Pro, that means about four full charges from a 20,000mAh Techsmarter power bank, compared with about six from a 30,000mAh model when charging by cable.
How much more power does 30,000mAh give you?
Comparing these Techsmarter capacities, 30,000mAh stores 50% more power than 20,000mAh. That gives you more backup, but it does not make your phone charge 50% faster.
The number of full charges depends on your device. An iPad needs more power than a small phone. Using your phone for maps, video or games while it charges also uses up the power bank sooner.
How many charges can I get?
When charging by cable:
- iPhone 16 or 16 Pro: about four full charges from 20,000mAh, or six from 30,000mAh.
- Samsung Galaxy S24 Ultra or S25 Ultra: almost three full charges from 20,000mAh, or about four full charges plus a 30% top-up from 30,000mAh.
- iPad (A16) or 11-inch iPad Air (M3): almost two full charges from 20,000mAh, or almost three from 30,000mAh.
Using your device while it charges will reduce those amounts. Wireless charging also gives you fewer charges than using a cable.
Does the bigger one charge a laptop faster?
Not necessarily. Battery size tells you how much backup power you have. The charging power tells you how quickly the power bank can send it to your laptop.
For example, a 20,000mAh power bank with a 100W laptop port can charge a laptop faster than a 30,000mAh model with a 45W port, if the laptop can use the extra power. The bigger battery gives you more backup; the stronger charging port can give you more speed.
What else should I compare?
For a phone, extra battery life may matter most. For a laptop, charging speed matters too. For camping, a rugged body and protection against rain and dust can be useful. More battery capacity does not automatically give you those features.
Which is easier to take on a flight?
The 20,000mAh Techsmarter models are below the standard 100Wh battery limit. Carry them in your hand luggage, never in checked luggage. The 30,000mAh models are above that limit and need airline approval under US rules; some airlines will not accept them.
For outdoor trips, the Rugged 20,000mAh model offers phone and tablet backup. The Rugged 30,000mAh 45W model adds more stored power and charging for compatible laptops.
Flight guidance: FAA rules for batteries and portable chargers. Airlines may apply stricter limits.