This modular power bank uses replaceable 21700 batteries

This new power bank is effectively modular and can therefore be fitted with fresh batteries when it runs out of power. How practical that is will depend on the specific use case, but in principle, several batteries can be kept in reserve. Compared with carrying around several power banks, this could offer a clear advantage in terms of space and weight. That being said, the Ampax is definitely not the first product in its category. Similar modular power banks are also available from AliExpress and Amazon, for example.

The 21700 batteries are found in many flashlights and some other devices these days, so it is possible that tech enthusiasts already own a pair or more. According to the manufacturer, the two batteries offer a capacity of 10,000mAh. At a nominal voltage of 3.7 volts, this should result in a capacity of 37 Wh, which is usually more than enough to charge a typical smartphone. The Ampax power bank has one USB Type-A port and one USB-C port, allowing two devices to be charged at the same time. Both ports can be used simultaneously, with the maximum output rated at 22.5 watts.

As part of the crowdfunding campaign, the power bank itself is currently available for $36, with shipping expected to begin in August. As usual with crowdfunding campaigns, there is a financial risk that should not be underestimated. Supporters who pledge $50 will also receive a compatible battery charger for four cells.