Recent typhoons and heavy rains have left local governments in some parts of Japan having to deal with reconstruction, and residents thinking more about being better prepared in the future. This month On: Tech looks at a few gadgets that could be useful during emergencies.

Small but powerful

When power grids go down, a good alternative energy source can make all the difference to survival. The PowerArQ is a powerful portable power supply that is smaller than cooler box and weighs just 6 kilograms. Its lithium-ion battery has a capacity of 174,000 milliampere-hour / 626 watt-hour, enough to heat an electric blanket overnight, and it can be recharged over 300 times.