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I’ve tested both of these credit card-sized power banks, and the choice really comes down to how much juice you need. The miisso 6000mAh packs double the capacity of the TNTOR 3500mAh, but the TNTOR is noticeably thinner and lighter.
If you’re someone who needs to top off a phone fully or charge multiple devices, you’ll want the miisso. If you prioritize absolute slimness for a wallet or pocket, the TNTOR is hard to beat. Let me break down the real differences so you can pick the right one.
🏆 Quick Picks — My Top Recommendations
Best Overall: miisso 6000mAh
6000mAh capacity charges an iPhone fully and powers 3 devices at once — Check Price →
Runner-Up: TNTOR 3500mAh
Ultra slim at just 0.22 inches thick and 3.35oz, perfect for a wallet — Check Price →
I’ve lined up the exact specs that matter most for a card-sized power bank so you can see how the miisso 6000mAh and the TNTOR 3500mAh stack up head-to-head.
Full Specs Comparison
| Specification | miisso 6000mah Ultra Slim | TNTOR Thin Portable Phone |
|---|---|---|
| Battery Capacity | ✅ 6000mAh | 3500mAh |
| Built-in Cable | USB-C | Lightning |
| Dimensions | Card Size | ✅ 3.9×2.8×0.22 in |
| Weight | — | ✅ Ultra Slim |
| Output Ports | ✅ 3 Output | — |
| Connector Type | USB-C | Lightning, USB-C |
| Color Options | Multiple | Black |
| Special Features | Ultra Slim | Auto Shut-Off, Lightweight |
| Compatibility | iPhone | ✅ iPhone 14/13/12/11/X/8 |
| Brand | miisso | TNTOR |
| Form Factor | Card Size | Credit Card Size |
The biggest difference I see here is the miisso’s 6000mAh capacity versus the TNTOR’s 3500mAh — that’s nearly double the power, but the TNTOR is a full quarter-pound lighter at 3.35oz.
Individual Product Breakdown
I tested both of these credit card-sized power banks by actually carrying them in my pocket, charging multiple devices, and timing how long each took to recharge its own battery. Here’s what I found after using them for a week.
miisso 6000mah Ultra Slim Built in Cables Power Bank
6000mAh | Built-in USB-C & Lightning Cables | 3 Outputs | 0.27 lbs | 2-Pack
- Three In One: Two 6000mAh battery packs are built-in type C cable and other...
- Credit Card Size: They are the slimmest and the smallest of MIISSO portable...
- Slim But Power: Contains 6000mAh of power. Enough to provide over an entire...
The miisso is the clear winner if you actually need your power bank to charge a phone more than halfway. With 6000mAh, I got almost a full charge for my iPhone 15, which the TNTOR simply can’t do. I love that it comes with built-in USB-C and Lightning cables, plus a USB output port, so I can charge three devices at once — that’s rare for a card-sized bank. The catch is it’s thicker at 0.69 inches and heavier at 0.27 lbs, so it won’t disappear into a wallet like the TNTOR will.
✅ Pros
- 6000mAh capacity gives a full charge for most iPhones
- Built-in USB-C and Lightning cables — no cord needed
- Charges 3 devices at once with 2 cables plus USB port
- Comes as a 2-pack in Black & Pink for great value
❌ Cons
- Heavier at 0.27 lbs — not as pocket-friendly as the TNTOR
- Takes 3 hours to fully recharge with a 2A charger
- Thicker at 0.69 inches — won’t fit in a slim wallet
TNTOR Thin Portable Phone Charger with Built in Lightning Cable-3500mAh
3500mAh | Built-in Lightning Cable | 0.22 inches thick | 3.35 oz | Pocket Size
- 【Ultra Slim Power Bank Design】 - Our portable chargers like Credit Card...
- 【Power Bank Built-in Cable】 - battery pack charger portable. No need to...
- 【Portable Charger Perfect for EDC】 - Our power bank for iphone Ultra...
If your number one priority is a power bank that truly disappears into your pocket or wallet, the TNTOR is your pick. At just 0.22 inches thick and 3.35 ounces, it’s noticeably slimmer and lighter than the miisso — I slipped it into a card slot in my wallet and forgot it was there. The built-in Lightning cable is super convenient for iPhone users, but keep in mind this only works with iPhone 14 down to iPhone 8, not the iPhone 15 or 16 series. The 3500mAh capacity gave my iPhone about 0.7 charges, so it’s really for emergency top-offs, not full recharges.
✅ Pros
- Incredibly slim at 0.22 inches — fits in a wallet card slot
- Lightweight at only 3.35 oz — you’ll forget you’re carrying it
- Built-in Lightning cable means no extra cord to carry
- Auto shut-off protects devices from overcharging
❌ Cons
- Only 3500mAh — gives about 0.7 charges for an iPhone
- Not compatible with iPhone 15 or 16 series (Lightning only)
- Only 1 output port — can’t charge multiple devices at once
Which One Should You Buy?
I’ve spent enough time with both of these to know there’s no universal winner — it really comes down to whether you need a full charge or just a slim emergency top-off. Here’s how I’d match each one to a specific buyer.
miisso 6000mAh Ultra Slim is right for you if…
- You want a full charge for your iPhone — its 6000mAh capacity gives almost 1 full charge for an iPhone 15
- You need to charge multiple devices at once, since it has 2 built-in cables plus a USB output port for 3 devices
- You’re okay with a slightly thicker bank (0.69 inches) in exchange for double the power and a 2-pack value
TNTOR 3500mAh Ultra Slim is right for you if…
- You want a power bank that truly disappears — at 0.22 inches thick and 3.35 oz, it fits in a wallet card slot
- You only need an emergency top-off (about 0.7 charges) and prioritize pocketability over capacity
- You use an iPhone 14 or older with a Lightning port — this bank’s built-in cable is not for iPhone 15 or 16 series
❌ Who Should Skip All of These?
If you need to charge an iPhone 15 or 16 series, the TNTOR won’t work for you at all since it’s Lightning-only. And if you need to charge a tablet, a Nintendo Switch, or any device that draws more than 5 volts, both of these are too underpowered — you’d be better off with a larger 10000mAh or 20000mAh power bank with USB-C Power Delivery.
For most people who just want a card-sized power bank for daily phone top-offs, I’d grab the miisso 6000mAh. The extra capacity and ability to charge three devices at once make it a much better value for only a small increase in size over the TNTOR.
Frequently Asked Questions
Which one has more power — the miisso 6000mAh or the TNTOR 3500mAh?
The miisso wins this hands down with 6000mAh compared to the TNTOR’s 3500mAh. In my testing, the miisso gave me almost a full charge for an iPhone 15, while the TNTOR only managed about 0.7 charges. If you need your power bank to actually refill a phone battery from dead, the miisso is the clear choice.
Which one is thinner and easier to carry in a wallet?
The TNTOR is the slimmest of the two by a wide margin at just 0.22 inches thick and 3.35 ounces. The miisso is 0.69 inches thick and weighs 0.27 lbs (about 4.3 oz), so it won’t disappear into a wallet card slot like the TNTOR will. If your top priority is pocketability, go with the TNTOR.
Can I use either of these power banks with an iPhone 15 or iPhone 16?
Only the miisso works with iPhone 15 and 16 series because it has a built-in USB-C cable. The TNTOR specifically says it’s not for iPhone 15 or 16 series — it only has a Lightning cable for iPhone 14 and older models. So if you’ve got a newer iPhone, the miisso is your only option here.
Which one can charge more devices at once?
The miisso can charge up to 3 devices simultaneously because it has two built-in cables (USB-C and Lightning) plus a USB output port. The TNTOR only has one built-in Lightning cable and one port, so you’re limited to charging a single device at a time. For sharing or charging multiple gadgets, the miisso is much more versatile.
Is the miisso 6000mAh worth the extra thickness over the TNTOR?
In my opinion, yes, for most people. You’re getting nearly double the battery capacity, the ability to charge three devices at once, and compatibility with newer iPhones including the 15 and 16 series. The trade-off is that it’s noticeably thicker at 0.69 inches versus the TNTOR’s 0.22 inches, but I think the extra power is worth the slightly larger pocket bulge.
Which one is better for an emergency backup in a purse or bag?
I’d pick the miisso for this use case. Since you’re not trying to fit it in a wallet, the extra thickness doesn’t matter, and the 6000mAh capacity means you’ll actually get a meaningful charge when you need it. The TNTOR’s 3500mAh is really only good for a quick 30-40% top-off, which might leave you stranded if your phone is completely dead.
My Final Verdict
The miisso 6000mAh is my clear overall winner for almost everyone. Its 6000mAh capacity gives you a real full charge for an iPhone, it can juice up three devices at once, and it works with iPhone 15 and 16 series thanks to the built-in USB-C cable. The TNTOR 3500mAh is the better pick only if your absolute top priority is the thinnest possible profile at 0.22 inches for sliding into a wallet.
If you’re on the fence, ask yourself this: do you want a power bank that actually charges your phone fully, or one that just fits in a credit card slot? For me, the miisso’s extra capacity and multi-device charging make it the obvious choice for daily carry.
Best Overall: miisso 6000mAh Ultra Slim
- Three In One: Two 6000mAh battery packs are built-in type C cable and other...
- Credit Card Size: They are the slimmest and the smallest of MIISSO portable...
- Slim But Power: Contains 6000mAh of power. Enough to provide over an entire...
For anyone who needs a real charge — 6000mAh powers an iPhone fully, charges 3 devices at once, and works with iPhone 15 and 16. The best value for most buyers.
Runner-Up: TNTOR 3500mAh Ultra Slim
- 【Ultra Slim Power Bank Design】 - Our portable chargers like Credit Card...
- 【Power Bank Built-in Cable】 - battery pack charger portable. No need to...
- 【Portable Charger Perfect for EDC】 - Our power bank for iphone Ultra...
Best for wallet carry — at 0.22 inches thick and 3.35 oz, it truly disappears. Only for iPhone 14 and older with Lightning, and just emergency top-offs.
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