XTAR PB2S Two Bay USB-C Battery Bank Charger

This is a charger from XTAR with two bays, one battery in each. It also works as a power bank, which means it can send power out over USB from the batteries sitting in it. Batteries are not included, so you supply your own.

What it does

As a charger, each bay gives up to 2A. The A is amps, a measure of how much current flows. As a power bank, it gives up to 2.1A out over USB from the cells you fit. It balances charge and discharge between the two cells, so they stay in step.

It has a few other features. 0V activation means it can start charging a cell that reads zero volts. Three-stage TC/CC/CV charging means the charge runs in three stages. And there is a magnetic cover.

Fits

18650 and 21700 are battery sizes, named for their measurements in millimetres: 18 wide by 65 long, and 21 wide by 70 long.

• 2 x 18650 batteries
• 2 x 21700 batteries, such as the Molicel P42A

Specs

• Power bank output: up to 2.1A USB
• Charging current: up to 2A per bay
• Conversion efficiency: up to 92% (how much of the power makes it through the charger)
• Cells are replaceable, so capacity depends on the batteries you fit

The batteries you fit decide how much it can hold, so choose those first.