Power banks for handheld gaming: capacity, PD output and what to check

A power bank is a portable battery pack that charges a device over USB. For a retro handheld, read three things on its label: capacity with a voltage, the USB-C output steps, and whether it states USB Power Delivery. Then compare them with the handheld maker's stated figures. No brand is named, because none has been sourced.

How big are handheld batteries?

Makers quote handheld batteries in milliamp hours (mAh). That is a count of charge, and it only becomes a count of energy once you know the voltage. Energy in watt hours (Wh) is the amount of charge in amp hours multiplied by the voltage. Two makers in our catalogue state the voltage, which lets us work it through.

Sources: Miyoo, Mangmi, Analogue, Anbernic and AYN's Odin 3 page. The Mangmi and Miyoo pages show why mAh alone misleads: the Mangmi is 5000mAh at 3.85V, so each mAh carries slightly more energy than the Miyoo's at 3.7V. Most makers give only mAh, so a Wh figure for those devices would be a guess, and we do not give one.

Why does Wh matter on a power bank?

A power bank label may show mAh, Wh, or both. If the pack states its rated voltage, you can convert it the same way: a pack labelled 10,000mAh at 3.7V works out to 37Wh by the same multiplication. Comparing that with a handheld's energy shows the rough ratio between them. The ratio is an upper bound, because the pack's labelled capacity describes its cells and the pack maker's own specification is the place to look for how much reaches a device. None of the maker pages cited here gives a conversion efficiency, so we make no promise about the number of recharges.

What output does a handheld need?

Makers state charging in different forms, so start with the handheld's own page.

• Retroid states 27W charging for the Pocket Classic, alongside a 5000mAh battery, on its product page.
• AYANEO lists the Pocket S with a 6000mAh battery and "Up to 40W PD fast charging", and notes the charger is not included, on its product page.
• Mangmi states "Supports 15W charging" for the Air X.
• Anbernic lists 5V/2A and about 3.5 hours to full for the RG556, which is 10W by volts multiplied by amps.
• AYN lists 60W charging for the Odin 3 in a spec image recorded for that device; the page text does not state it.

The USB-IF describes PD on usb.org as including an adjustable mode in which the powered device can request intermediate voltages up to the charger's maximum. In plain terms, the handheld asks and the supply answers. A pack whose label lists only 5V cannot offer the voltage steps that a 27W or 40W figure points to, so check that its USB-C output lists higher voltage steps; the chargers in our best accessories list show what that looks like. For how to read those lines, see USB-C charging explained.

What should a power bank label say?

1. Capacity with voltage. mAh plus a voltage, or a Wh figure.
2. A USB-C output with voltage steps. Not only a single 5V line.
3. Single-port wattage. AYN's charger shows how a combined figure (45W plus 18W) differs from a single-port 65W.
4. A PD statement. Retroid's 35W charger lists voltage steps without naming PD, so a missing word is not proof of a missing feature, but a stated one is firmer.
5. The cable. The pack may include none, and the handheld makers who ship a Type-C cable state no cable rating.

Worked example: how much pack is enough?

Take the Mangmi Air X, where both figures are stated: 5000mAh at 3.85V is 19.25Wh by our arithmetic, and the maker lists 15W charging. A hypothetical 37Wh pack, the 10,000mAh at 3.7V example above, holds a little under twice that energy, which is the upper bound on how many full charges it could give before any losses. Dividing 19.25Wh by 15W gives 1.28 hours, which is the shortest time a full charge could take at that rate if the handheld drew 15W throughout. Mangmi does not state a charge time, so this is arithmetic, not a claim about the device.

The exercise shows what the numbers can and cannot tell you. They bound the answer; they do not predict it. Anbernic's RG556 gives the other kind of figure, a maker-stated 3.5 hours to full at 5V/2A, and Powkiddy states 2 hours of charging for the RGB30 and V10, each from its own battery.

How much handheld does a pack hold?

With a voltage on both sides, energy in watt hours gives a ratio. The table compares two hypothetical packs, 10,000mAh and 20,000mAh at 3.7V, with the two handhelds whose makers state a voltage.

These ratios are ceilings. A pack's labelled capacity describes its cells, and none of the maker pages cited here states how much of it reaches a device, so the true number of full charges is lower. For handhelds that give mAh without a voltage, such as the 8000mAh Odin 3, no honest ratio exists, and guessing a voltage would only invent a figure.

A short buying check

Put the handheld's page and the pack's label side by side, then work through these steps in order.

1. Write down the handheld maker's charging figure, or the volts and amps if that is what it gives. If it gives nothing, as on the Retroid Pocket 6 page, note that the question is open.
2. Find the pack's USB-C output line and confirm it lists a step that reaches that wattage on one port.
3. Convert the pack's capacity to Wh using its stated voltage, then compare it with the handheld's Wh if the maker states a voltage.
4. Look for the word Power Delivery on the pack. Its absence is not proof of absence, but its presence is firmer.
5. Check the weight and size on the pack's own specification; the handheld makers cannot tell you that.

A pack for a 15W handheld such as the Air X has a lower bar than one for the 27W Pocket Classic or the 60W Odin 3. If the pack's label cannot reach the stated wattage, the makers do not say what happens, so treat that pack as a poor match.

Can you take a power bank on a plane?

Check before you travel. On its page about electronic devices and electrical items, gov.uk says: "Check the restrictions on certain types of batteries or contact your airline if you're not sure what you can carry." It also says to make sure devices are charged before you travel, and that a device which will not switch on when asked will not be allowed on the aircraft. The page lists mobile phones, laptops and tablets as allowed in hand and hold luggage and notes that some airlines have different restrictions. It does not mention power banks or handheld consoles by name and gives no watt-hour limit, so the pack's Wh figure and your airline's rules are the things to look up. This is another reason a pack that states Wh is easier to deal with than one that gives mAh alone.

How does a power bank fit with the rest of your kit?

A pack helps with long sessions away from a socket, but it does not change the battery-life claim a maker makes. For how to read those claims, see our battery life guide. For other add-ons, including docks and cases, browse accessories, and for wider explainers see guides. Our approach to sourcing is on how we research.