The INIU and Charmast are the two best-selling portable chargers on Amazon, both priced around $20 with 10,000mAh capacity. But they solve different problems: the INIU focuses on raw charging speed with 45W PD output, while the Charmast eliminates cable clutter with 4 built-in cables. We compared verified buyer data from nearly 100,000 combined reviews to help you pick.
Short answer: The INIU is the better charger if speed matters most — it charges an iPhone to 60% in 25 minutes. The Charmast wins on convenience with built-in cables for every device type. See all our picks in the full best portable chargers guide.
 INIU |  charmast | |
|---|---|---|
| Price | $19.98 | $20.99 |
| Rating | ★★★★½ 4.5 | ★★★★½ 4.6 |
| Reviews | 76,639 | 20,893 |
| Capacity | 10,000mAh | 10,000mAh |
| Max Output | 45W PD | 22.5W |
| Built-in Cables | 1 USB-C cable | 4 cables (USB-C, Lightning, Micro-USB + input) |
| Ports | Dual USB-C (in & out) | 6 outputs, 3 inputs |
| Fast Charge | iPhone to 60% in 25 min | Standard fast charge |
| Best For | Raw charging speed | Charging multiple devices without cables |
INIU: The Speed Demon
Portable Charger, Ultra Slim 45W Fast Charging with Attached USB C Cable,
INIU holds a 4.5-star average across 76,639 verified Amazon reviews. ROXY wrote: “The blue version also has LEDs in the paw in case anyone was wondering due to the pictures of the blue model only showing it with the lights out. The blue version I recieved has white LEDs for the paw and they show how…”
- From INIU--the SAFE Fast Charge Pro
- Industry First-Seen High-Density TinyCell
- Charge iPhone 16 to 60% in 25 Mins
- Only 5% Got USB-C IN & OUT
What we like
- From INIU--the SAFE Fast Charge Pro: Experience the safest charging with over 38 million global users. At INIU, we use only the…
- Industry First-Seen High-Density TinyCell: INIU's latest 10,000mAh power bank features the market's first high-density cell, making it 30%…
- Charge iPhone 16 to 60% in 25 Mins: Equipped with a powerful integrated 45W chip. It charges an iPhone 15 to 60% in just 25 mins.
- Only 5% Got USB-C IN & OUT: INIU stands out with its unique dual USB-C ports, both for input and output. Unlike others only recharge via…
Watch out for
- No common complaints in top verified reviews
The INIU's headline feature is 45W PD fast charging — that's the same wattage as many laptop chargers. With 76,000+ reviews and a 4.5-star average, it's one of the most proven power banks on Amazon. The high-density TinyCell technology makes it 30% smaller than typical 10,000mAh banks. Dual USB-C ports (both input and output) give it flexibility that most competitors lack.
The trade-off: it only comes with one built-in USB-C cable. If you use Lightning or Micro-USB devices, you'll need to carry your own cables. It's a power-focused product, not a convenience one.
Charmast: The Cable-Free Solution
Portable Charger with Built in Cables, Power Bank with Cords Wires, Slim
charmast holds a 4.6-star average across 20,893 verified Amazon reviews. Su wrote: “This is an amazing phone charger! The chargers size and weight is about as much as a phone. I like the color too. It charges a little slower than a phone, but can charge a phone like 2 a half times fully on one charge.…”
- 🔋【Portable charger with built in
- 🔋【6 Outputs and 3 Inputs】Portable
- 🔋【Super Slim
- 🔋【Universal compatible with All popular
What we like
- 🔋【Portable charger with built in cables】Slim portable charger built-in 4 cables included 3 output cables and 1 input cable. Total 3…
- 🔋【6 Outputs and 3 Inputs】Portable charger has 6 outputs and 3 inputs, you may charge 6 devices max at the same time, recharge battery…
- 🔋【Super Slim, Accurate Percentage of Remaining Juice】 Slim 10000 power bank, its dimmension is 5.68''x2.63''x0.69'', and weigh only…
- 🔋【Universal compatible with All popular devices】As portable phone charger builts in all ports, multi cables, it is widely compatible with…
Watch out for
- No common complaints in top verified reviews
The Charmast takes the opposite approach: 4 built-in cables cover USB-C, Lightning, Micro-USB, and a dedicated input cable. Six outputs mean you can charge up to 6 devices simultaneously. At 4.6 stars across 20,000+ reviews, buyers consistently praise the convenience of never needing to remember cables.
The trade-off: 22.5W max output is less than half the INIU's speed. If you're topping up a phone before a meeting, you'll feel the difference. The slim form factor (0.69" thick) partially makes up for it — this is the power bank you grab without thinking.
The Verdict
Get the INIU if...
- Charging speed is your top priority
- You primarily use USB-C devices
- You might need to emergency-charge a laptop
- You already carry your own cables
Get the Charmast if...
- You hate carrying separate cables
- You charge multiple device types (USB-C, Lightning, Micro-USB)
- You want to share one charger with family or coworkers
- Convenience matters more than raw speed
Frequently Asked Questions
Which portable charger charges an iPhone faster, INIU or Charmast?
The INIU is significantly faster. Its 45W PD output charges an iPhone 16 to 60% in about 25 minutes. The Charmast's 22.5W output is fast by general standards but roughly half the speed of the INIU for iPhone charging.
Can I charge a laptop with either of these power banks?
The INIU's 45W output can slow-charge some laptops (MacBook Air, Chromebooks). The Charmast's 22.5W output isn't enough for most laptops. Neither replaces a dedicated laptop charger for heavy use, but the INIU can keep a MacBook Air alive in a pinch.
Which one is better for travel?
Both are under 10,000mAh and TSA-approved for carry-on luggage. The Charmast has the edge for travel because its built-in cables mean you don't need to pack separate charging cables — it has USB-C, Lightning, and Micro-USB built in. The INIU is slimmer and faster if you only carry USB-C devices.
Do both power banks support pass-through charging?
Both support charging your phone while the power bank itself is being recharged. The INIU's dual USB-C ports make this more seamless since you can use one port for input and one for output simultaneously.
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