New semi-solid-state power banks launch with a battery that's "hard to set on fire"

Tama Denshi Kogyo is a Kawasaki accessory maker that has been around since 1976. The company is now putting semi-solid-state cells into six new power banks, and they go on sale in Japan today. It is a small launch from a company most readers outside Japan will not know. However, it is launching in the middle of an industry shift; more on that later.

There are three capacities, each in black and white. The 10,000 mAh TLP158UC pushes up to 45 W over USB-C and costs 7,980 yen (~$50). The 15,000 mAh TLP159UC and 20,000 mAh TLP160UC both climb to 67 W, at 10,800 (~$68) and 12,800 yen (~$80). All three come with a captive USB-C cable alongside a USB-C port and a USB-A port, a charge-level readout, and over-current and over-voltage protection.

Total output collapses to 30 W once more than one connection is drawing power. The 67 W figure that makes the larger two credible for a laptop only applies when nothing else is plugged in. Charging three devices at once, as the company suggests, means sharing 30 W between them.

The battery itself uses a flame-retardant gel in place of the usual liquid electrolyte. Tamadenco claims reduced fire risk, roughly 2,000 cycles, and steady output in heat and cold. It's worth noting that semi-solid is not solid-state. There is still liquid in the cell, and Japan is targeting practical all-solid batteries around 2030.

About that industry shift we talked about earlier; the timing is not accidental. Elecom shipped a comparable 10,000 mAh unit in March at 8,480 yen, and Japan banned in-flight power bank use on April 24 after the country logged 123 battery-related accidents in 2024. Sales will be held through electronics chains, home centres and Tamadenco's own store. No word on any release beyond Japan.