10%
OFF
Save 10% at Charmast with code STACKWELL19
Apply at checkout. Works across the 5,000, 10,000 and 20,000mAh ranges.
C
Charmast Coupon Codes & Deals
1 code
Best: 10% off
Listed: October 2026
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Power banks with built-in cables and fold-out wall plugs — 5,000 to 20,000mAh, backed by a three-year warranty.
About Charmast
Charmast only makes power banks, and one design choice runs through the whole range: built-in cables. The pack carries its own USB-C, Micro-USB or Lightning connector, so you are not hunting for a cable when the phone is at 4%. Several models also fold out an AC wall plug, which turns the pack into its own charger.
Capacity splits three ways. The 5,000mAh minis have a built-in connector and 20W PD output, sized to sit in a pocket. The 10,000mAh models are the middle of the range and where most of the variants live — built-in cables, LED or LCD charge displays, AC plug versions and 22.5W fast charging. The 20,000mAh packs are the travel option, rated by Charmast at three to four full phone charges.
Charmast lists the United States, United Kingdom, Canada, France, Germany, Italy and Spain among its destinations, and covers manufacturing defects under a three-year limited warranty — long for this category, where one to two years is the norm.
How to use a Charmast coupon code
- Decide the capacity before you shop: 5,000mAh for a pocket top-up, 10,000mAh for a full day out, 20,000mAh for travel.
- Copy the code with the Get Code button — the store opens in a new tab at the same time.
- Check the built-in connector matches your phone. The cable is the point of these packs, so the wrong connector makes the model useless to you.
- Paste the code at checkout and confirm the 10% has come off.
Charmast coupon FAQs
What does code STACKWELL19 give me?
10% off your Charmast order.
What warranty do Charmast power banks carry?
A three-year limited warranty covering manufacturing defects under normal use.
How many phone charges does the 20,000mAh pack give?
Charmast rates it at three to four full phone charges.
Which countries does Charmast ship to?
The store lists the United States, United Kingdom, Canada, France, Germany, Italy and Spain.
Can I take these power banks on a plane?
Airline limits are set by capacity in watt-hours, not by Charmast. Check your airline's rules before flying with the 20,000mAh models.
Our Charmast review
Review
Charmast power banks: who should skip them
Charmast makes one thing — power banks with the cable already attached. How the three capacity tiers differ, why the three-year warranty matters more than it sounds, and the two terms the brand does not publish up front.