This is critical as currently, they pretty much require mains power for any real work).

All EL90 models could be powered from regular mains power.

In particular, many laptop computers can measure the rate of battery use (when not connected to mains power).

Please note, there'll be no mains power for amplification available.

Current usage by country or region is given in the list of mains power around the world.

I was myself briefly bearded when we lost mains power a year or more ago.

When mains power comes back, the wheel gathers speed again in around 15 minutes.

These systems require either mains power or 12 V deep cycle batteries.

There are no trucks, cars, mains power or airports on the island.

When mains power is available, it will charge the DC battery.