This power bank can be used underwater (but we don’t recommend it)

Nitecore NBP 4 Waterproof Power Bank

Nitecore NBP 4 Waterproof Power Bank

Adrian Kingsley Hughes

One day I looked at what I consider One of the best waterproof power banks I’ve come across. But it has one limitation – it is waterproof only if small rubber covers are installed that protect the ports.

Not a huge limitation, but what are the chances of forgetting to apply the rubber caps before the critical point where the power bank gets soaked?

very high.

What I want is a waterproof power bank without the need for little rubber covers over the ports.

I found one. The Nitecore NBP 4.

  • Battery Type: 4 Lithium-ion batteries 21700
  • eligibility: 20,000 mAh 3.64 V (72.8 Wh)
  • rated power: 12400 mA 5V
  • ports: 2 x USB-A, 1 x USB-C, 1 x microUSB
  • Enter:
    Micro-USB 5V – 2.4A / 9V – 2A
    USB-C 5V – 3A / 9V – 2A / 12V – 1.5A
  • production |:
    USB-A 5V – 3A / 9V – 2A / 12V – 1.5A
    USB-C 5V – 3A / 9V – 2A / 12V – 1.5A
  • electronic identification number level: IP68
  • Dimensions: 103.5 x 51.3 x 49.5 mm / 4.07 x 2.02 x 1.95 inches
  • Weight: 378 g / 13.33 oz.
  • complements: USB-C charging cable, high strength nylon holder

The NPB 4 has several fast charging output ports and provides a maximum output power of 18W, which is enough for things like smartphones and tablets but not enough for heavy loads like laptops.

The power bank has enough power to charge an iPhone about half a dozen times, or AirPods a whopping 32 times, yet the power bank is small enough to allow it to fit onto commercial planes.

Lots of ports and lots of power for smartphones and tablets

Lots of ports and plenty of power for smartphones and tablets.

Adrian Kingsley Hughes

On the side of the NPB 4 there is a touch sensor power level display which shows three blue LEDs when the charge level is around 100%, two lights at 70% and one at 30%.

The charging indicator is built into the front of the power bank, and both the device and the touch sensor work when wet

The charging indicator is built into the front of the power bank, and both the device and the touch sensor work when wet.

Adrian Kingsley Hughes

Oh, and if you’re wondering what those little clips on the side do, well, they baffled me too. Looks like they let the power bank plug in Nitecore HU60 LED Headlights.

If you don’t have this headlight, it’s a handy fidget tool to use.

These clips allow the power bank to be attached to the Nitecore HU60 LED headlights

These clips allow the power bank to be attached to the Nitecore HU60 LED headlights.

Adrian Kingsley Hughes

From a safety standpoint, the NPB4 has everything you would expect from a modern power bank, including overcurrent protection, overdischarge protection, short circuit protection, and everything encased in a fire-retardant polycarbonate casing.

But it is this waterproofing that I really like here. Power banks are usually waterproof if and only if you cover the outlets with rubber seals. This is not the case with the NPB 4. Notecore used a high-strength O-ring on the charging port and advanced glue-molding technology to protect the internal components from water.

And it works really well!

Nitecore NPB 4 Cools Underwater

Nitecore NPB 4 cools underwater.

Adrian Kingsley Hughes

But can you use it underwater?

Well, Nitecore says you can. Here’s a video showing it turning on while it’s charging and turning on three devices, all while submerged:

I tested this, and yes, it works well underwater. However, I would be careful for several reasons.

First, while it should be safe to charge underwater, I’ve come across poor quality or defective chargers where metallic parts (a fancy word for connection) are referred to as main power. I wouldn’t want to put my hand in this water if that was the case.

Second, water will get into the cables and outlets, which can cause small short circuits. In my experience, some USB devices can start to act funny when this happens, and there is a possibility of damage.

Even the Nitecore guide is very cautious when it comes to water:

Here's what the Nitecore guide has to say about immersion

Here’s what the Nitecore guide has to say about immersion.


This is why I do not recommend you to use the power bank while immersed. If you do, the danger is upon you. I also like to keep it away from salt water and chemicals.

However, this is a power bank that I happily left outside for extended periods of time to power my camera or GoPro, and let it get wet during use. It is very resistant to rain and condensation, and the risk of problems is much lower than if the power bank was submerged.

also: GoPro Hero 11 Black First Look: The world’s best action camera gets better

all in all , Nitecore NPB 4 is a great power bank. Lots of capacity, easy to use, durable and reliable, and a level of waterproofing gives me a lot of confidence in the product.

It’s not cheap, but good power banks aren’t cheap.

If you’re in the market for a smaller power bank, Nitecore makes too 5000 mAh NPB 1and 10000 mAh NPB 2.

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