Ukraine’s national energy company has urged citizens to “charge everything” by 07:00 (04:00 GMT) Thursday because of expected power cuts caused by Russian missile strikes.
Energy plants were hit by Russian missiles again on Wednesday – part of a wave of such strikes since 10 October.
Outages of up to four hours at a time will affect the whole country on Thursday, grid operator Ukrenergo said.
Phones, power banks, torches and batteries need to be charged, it urged.