On a low day, a normal to-do list turns into a wall. This method plans around the energy you actually have.
Before you look at tasks, pick a number: full, half, low or empty. That number decides how big the plan is allowed to be.
On a low day the plan is one thing that would make tomorrow easier, like paying a bill, eating a real meal or replying to one message. Everything else is a bonus.
Make the other tasks smaller: 'clean kitchen' becomes 'load 5 dishes'. Small steps you finish beat big ones you avoid.
Decide in advance when you're done for the day. Resting on purpose is part of the plan.
Not medical advice. If low energy lasts or worries you, talk to a doctor.
Want all of this ready to print? The Low-Battery Day Planner Kit has 14 pages (US Letter + A4).