Tollcuudda Waterproof 10000mAh Solar Powerbank

I bought this Tollcuudda Waterproof 10,000 mAh solar power bank from Aliexpress. It turns out that it cannot deliver 2.1A as claimed, nor is it really 10,000 mAh. It’s also not waterproof. Do not buy.

Here’s the Aliexpress link, but do not buy…

It’s suspiciously similar to an 8,000 mAh one I bought from Banggood at around the same time which was a little cheaper, but that one didn’t lie about it’s capacity or make other false claims. I still wouldn’t recommend it, but at least this one is basically honest.

Video Review

I did a brief teardown of both of the power banks in this video. There are some minor differences, but they use the same driver board, and both appear to be 8,000 mAh.

In the box

The box that the powerbank comes in

The box is massive for some reason, and filled with foam. It contains the powerbank, a cable, manual and a karabiner.

The foam and contents, showing the built in LED light

The LED light turns on and off with a double press of the power button.


  • Dimensions: 138 x 76 x 17 mm
  • Capacity: 10,000 mAh / 37 Wh claimed, 8,000 mAh actual.
  • Weight: 212.7 g
  • Micro USB cable length: 30 cm
  • Input: 1 micro-USB, 1A
  • Output: 2 USB A - 5V up to 2.1A claimed, 1A total in reality.
  • Solar panel, LED Light, Waterproof (not really, but would resist light rain/splashes)

Power supply

Significant voltage drop above 1.2A on either port. Turns itself off at 1.4A. Absolutely cannot do 2.1A despite claims, and is unable to deliver 1A per USB port if they’re both in use. On teardown it turns out that it contains a Hotchip HT4936S power bank controller. According to the HT4936S datasheet, it is only supposed to deliver 1A, so this poor performance is by design rather than a fault with this power bank.

The solar panel does appear to charge the power bank, but only at a very low rate (a few milliamps) and only in very bright light. The LED indicator lights up even when there is not enough light to actually charge the battery.

Cable test

5% voltage drop at 2.1A. Basically fine for an included cable with a cheap powerbank.

Capacity Test

66.5% of the claimed 10,000mAh capacity which is not very good. On teardown it turns out that it only contains an 8,000 mAh cell, so they’ve lied about the capacity.

Display Accuracy

The fairly standard 4 LEDs indicating 25, 50, 75 and 100% charge. They seem to be reasonably accurate.

Standby Power Loss

Seems fine, it’s been on my shelf for 3 months, and seemed to be around 23 full.

Passthrough power

Seems to work. Output resets when input power is cut.