Power & Batteries
Watts, watt-hours, and why the label on a device overstates what it uses
Ratings describe a maximum, tariffs charge for accumulated energy, and confusing the two produces most household energy…
Power & Batteries
Charging, chemistry, heat and why capacity fades.
21 articles · updated August 11, 2026 · page 2 of 2
Power & Batteries
Two devices argue about voltage before any fast charge begins
A charger starts at a low safe default and stays there unless a conversation persuades it otherwise. Most slow charging is a failed…
Power & Batteries
A charging cable is a resistor you chose without noticing
Every conductor drops a little voltage, and at the currents modern devices draw, a little is enough to change how fast anything…
Power & Batteries
Cold does not drain a battery, it hides the charge until things warm up
A phone that dies at a bus stop in winter usually has plenty of energy left. The chemistry has simply become too sluggish to…
Power & Batteries
A solar panel almost never produces the number printed on its back
That figure comes from a defined laboratory condition with a particular light level and temperature, and the roof outside matches…
Power & Batteries
Why a smoke alarm suits a disposable cell and a camera flash does not
Single-use and rechargeable chemistries fail in opposite ways. One leaks its charge away over months, the other leaks its contents…
Power & Batteries
A capacitor charges in seconds, and that is not the advantage it sounds like
Storing charge on a surface rather than in a reaction makes it fast, durable and almost unbelievably bad at holding very much.
Power & Batteries
An uninterruptible supply buys you seconds, and the seconds are the point
It is not a way to keep working through a power cut. It is a bridge long enough for something to shut down without corrupting…
Power & Batteries
What happens to a battery after it stops holding a charge
A pack that a device rejects still contains energy, valuable metals and a genuine fire risk, and the hardest step is getting it…