Promate Universal 20000mAh Ultra-Slim Power Bank with 20W USB-C Input/Output Port, QC 3.0 Output, USB-C Ports, LCD Display and Over-Heating Protection for Smartphones and Tablets - Black / BOLT-20PD.BLACK / BOLT-20PD.BLACK

The Promate BOLT-20PD is a universal 20000mAh power bank in black, built around a 20W USB-C input and output port, Quick Charge 3.0 output, an LCD display and over-heating protection. It is sized for smartphones and tablets, and the ultra-slim body is the reason a pack this size still fits a jacket pocket.

The USB-C port delivers 20W, which is the tier modern phones use for their fastest charging. At that rate a phone moves a long way during a short stop rather than gaining a few percent, and the difference is most obvious when you are charging between meetings instead of overnight.

A QC 3.0 output sits alongside the USB-C port, covering devices that negotiate over Qualcomm's Quick Charge standard rather than USB Power Delivery. Supporting both is what makes the BOLT-20PD genuinely universal, because which standard a phone uses is decided by its chipset, not by the cable you own.

The 20W USB-C port works as an input as well as an output, so the BOLT-20PD refills through the same connector it charges from. On a 20000mAh pack that matters: a bank this size takes real time to refill, and a 20W input is what keeps that from stretching across a whole night and the next morning.

An LCD display shows the pack's charge level as a number rather than a row of indicator dots. On a large bank that reading is what makes the capacity usable, since four dots cannot tell you whether there is enough left for a laptop top-up or only a phone.

Over-heating protection is built into the BOLT-20PD, watching the pack while it is charging or discharging. Heat is the failure mode that matters most on a high-capacity lithium battery, and protection circuitry is the part of the specification you never see working, which is exactly why it is worth checking for.

Promate builds the BOLT-20PD as an ultra-slim pack, which is the notable part at 20000mAh. Capacity usually arrives as thickness, and a slim profile is what decides whether a bank slides into a laptop sleeve or a back pocket instead of taking up a corner of the bag on its own.

The BOLT-20PD is specified for smartphones and tablets, which is where 20000mAh does its most useful work: a tablet takes a substantial share of any pack, so a bank that can refill one and still have capacity left for a phone is the practical minimum for travelling with both.

Promate describes the BOLT-20PD as universal, meaning the combination of USB-C and Quick Charge outputs covers the devices most people carry rather than a single ecosystem. This version is finished in black, which keeps it unobtrusive on a desk or in a bag alongside a laptop.