Power & Batteries
Battery percentage is an estimate, and a fairly rough one
Your device does not measure charge directly. It infers it, and the inference drifts.
Wren Halloway
Software writer, Tech Behind Things
Wren writes about operating systems, file formats and why software gets slower.
Contact Wren through our contact page — mark your message for their attention and it will be passed on.
16 articles
Networks
DNS decides far more than which address you reach
The name resolution step happens before any connection and quietly controls performance, filtering and a good deal of privacy.
Networks
What actually limits your broadband, and it is rarely the headline speed
The path from your device to the internet has half a dozen possible bottlenecks, and the advertised number describes only one of…
Networks
How a phone hands your call to the next tower without dropping it
Moving between cells while a conversation continues is a coordinated handover, and the way it fails explains where calls drop.
Networks
What a speed test measures, and the four things it cannot
A single number to a nearby server describes one narrow condition, and most complaints about a connection live outside it.
Networks
Almost all intercontinental traffic runs through cables on the seabed
Satellites carry a rounding error. The internet between continents is a few hundred physical cables, and their geography shapes…
Power & Batteries
Wireless charging wastes energy as heat, and the heat is the real cost
Inductive charging trades a measurable amount of efficiency for convenience, and the losses land inside the device next to the…
Power & Batteries
Why a 10,000mAh power bank will not charge a 5,000mAh phone twice
The capacity printed on the case is measured at a different voltage from the one your phone receives, and conversion costs more on…
Power & Batteries
Not all lithium batteries share the same chemistry, and the rules change with it
Cells sold under one umbrella term differ in energy density, lifespan, safety and how they should be charged.
Power & Batteries
Heat is what actually ages your electronics
Chemical and physical degradation processes speed up with temperature, which makes cooling the most effective form of maintenance…
Power & Batteries
What is actually inside a phone charger
A small brick converts mains alternating current into a precisely regulated low-voltage supply, and the way it does it explains…
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
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
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
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…