| Pros | Cons |
|---|---|
| Excellent performance | 20W max output |
| Great design | Slow recharge speed |
| Budget friendly | Dual USB-A ports |
| Occasional buzzing noise during charge | |
| Unreliable charging display |
When it comes to battery banks, we buy a ton, then bully them by draining them at every speed imaginable, recharging them like maniacs, and just hoping nothing burns up in the process. The Iniu Slim 10K is ranked #9 in our 2025 roundup and it’s one of the strangest little power banks we’ve tested so far.
Looking for power banks that actually perform? Check out our Top 5!
How We Test
We’re reviewers – not influencers. What does that mean? It means we test everything our way before we share the results. None of the content we produce is sponsored so you don’t have to wonder if we’re just trying to sell you something.
For battery banks in 2025, here’s what what we tested:
- Charging protocols – We did timed charge tests for every protocol that the battery bank claimed. For example, a battery bank might advertise PDO’s of 15W, 27W and 60W. We would run voltage stability tests for each rate. We do the same for PPS as well.
- Temperature – We captured the temperature of the battery bank for all the charge tests and noted any overheating, throttling or failure to maintain the chosen output.
- Capacity test – We fully charged and discharged each battery bank using a PD controller and an e-load. This method pushes the battery harder than normal use, revealing when it fails to maintain proper output instead of just dropping to a lower voltage.
- Recharge tests – We measure and timed the amount of energy required to fill the battery bank completely. We didn’t rely on the counters on the packs, instead we had hard cutoffs coded into our test programs
- Efficiency – From our charge/discharge tests, we calculated several efficiency values to see how much usable energy you get compared to how much went in.
Design
Iniu Slim really shines in the design department. At just 202g, this pack ranks #2 for Wh per gram and #1 for Wh per cm³. Iniu wasn’t lying when they called this one of the slimmest packs out there and it delivers on both form and function.
This is a 10,000mAh, 37Wh battery bank with two USB-A ports and one USB-C. If that screams “budget” to you, you’re not wrong. But what it lacks in modern port selection, it makes up for in slimness and practicality. It comes with a basic screen that tries to show capacity and status though it’s a bit cryptic. Max output is 20W, and it supports two PPS ranges along with basic 15W/18W/20W PDOs. There’s even a flashlight and a phone stand tucked in. Unexpected? Yes. Welcome? Also yes.
Performance
The Iniu Slim scored surprisingly well in our charging accuracy tests: a 93.7% PDO accuracy (ranked #3) and an 88.3% PPS score (ranked #5). Discharge testing revealed 28.26Wh pulled from the stated 37Wh, which puts its efficiency at a solid 76.4% (ranked #2 overall). For a slim budget bank, that’s impressive. But it comes with quirks: slow recharge speeds (up to 3 hours) and an odd charging pattern as Iniu took 2.5 hours to hit 66%, then jumped the rest in 30 minutes. Also… it buzzes when charging. Just slightly. But only one product in our whole test group did that, and it was this one.
If you want to find other great battery banks as this one, check out our Top 5 list!
Thermals
Thermal performance was within acceptable bounds. Discharge temps averaged 45.7°C, and recharge temps stayed at 36.2°C. No issues here, but not exactly standout either.
Value
For $27, you get a slim bank, decent performance, a flashlight, a phone stand, and a USB-C cable. But for $9 more, you could get something with faster charging, better thermals, and modern ports. Still, if you’re on a tight budget, it’s hard to go wrong here.
Verdict
If all you care about is price, this might be the best bang-for-buck power bank around. But if you’re picky about speed, stability, and a clean user experience, you’re better off spending a bit more. Great efficiency, but quirky design and slow speeds hold it back.
If you want to see what our Top 5 Battery Banks are for 2025, check out this list!