Maxell prototypes a 302°F wireless-charging solid-state battery module

Inside a package measuring 14.5 millimeters in diameter and 25.2 mm in height, Maxell has fitted a rechargeable all-solid-state battery module designed to handle temperatures up to 302°F. It keeps the 1/2AA form factor and 3.6-volt output of a conventional ER battery, so it targets equipment already built around that size and voltage.

The difference appears when the battery needs servicing. Instead of opening the device to replace a non-rechargeable ER cell, operators could use a dedicated wireless charger. Maxell has integrated the rechargeable cells with a wireless charging circuit and a boost circuit, allowing the module to add that capability without a complicated redesign of the existing equipment.

The company has developed two versions. One is designed to operate at temperatures up to 257°F; the other is intended to withstand as high as 302°F. That range is aimed at compact industrial sensors, smart meters and Internet of Things devices where battery access is difficult or an opening could weaken protection against moisture and other environmental factors.

One concrete test case is a temperature logger for retort food sterilization. Maxell is conducting a joint feasibility study with House Foods Corporation on equipment that must tolerate high heat while limiting moisture ingress. Fewer battery replacements could reduce maintenance visits and discarded batteries in equipment deployed in large numbers or hard-to-reach locations.

In practice, the technology could turn battery replacement into wireless servicing for selected sealed devices, but it is not yet a drop-in universal accessory. The charger is tailored to each customer’s equipment, and Maxell says some enclosure materials may block wireless charging. The module remains under application evaluation: commercial availability and a production timeline have not been announced.