Good and bad charging techniques

If you’ve been a mobile phone user since the Noughties, you’ll have encountered various charging cables and connections throughout your ownership history.

Each provided charge at different rates, to devices whose ability to store power also varied hugely.

In recent years, there’s been rapid uptake of low-wattage wireless charging from base plates or even other smartphones.

Given electricity’s relative complexity, plus the emergence of fast-charging cables, consumers tend to plug their phone in and promptly forget about them.

However, this can damage a device’s lithium-ion battery, potentially shortening its lifespan – and by definition, the phone’s life, unless it supports removable batteries.

So which good and bad charging techniques should consumers be aware of?

Full to bursting

Because our phones also serve as alarm clocks and bedtime companions, it’s common practice to put them onto charge before falling asleep.

However, ongoing voltage stress adversely affects the metallic lithium.

Instead, aim to charge the battery at 20 per cent, and stop at 80 per cent. This should maximise the battery’s potential lifespan.

Apple iOS 13 supports an Optimised Battery Charging setting which stops charging at 80 per cent, providing a final top-up in the moments before pre-scheduled disconnection.

Avoid the parasites

You probably aren’t familiar with the concept of parasitic loads, but it’s something many of us do without realising.

Charging a phone while conducting intensive activities like video streaming or gaming traps specific battery cells in a constant charging-and-depletion cycle, shortening their lifespan.

This also generates heat – batteries lose capacity more quickly at higher temperatures, and become less effective over time.

Stay cool

Because heat can affect battery performance and endurance, it’s important to consider ambient temperature alongside other good and bad charging techniques.

Never leave a charging phone in direct sunlight, or near a heat source like a radiator or cooker hob.

Similarly, prevent it being buried beneath quilts or cushions which could prevent the handset from dissipating heat effectively. A flat, cool surface is the optimal charging location.

Run flat tires the battery

Modern lithium-ion batteries don’t need periodic depletion like their nickel hydride ancestors.

A deep discharge (where the handset is forced to power down) can wear batteries out more quickly than regular top-ups between 20-80 per cent.

Indeed, research suggests batteries have to work hardest when they’re completely full or almost totally drained.

Mix and match

Fast-charging cables are great for quickly replenishing a depleted battery, but they work best up to 70 per cent.

After that, they’re forced to slow down to prevent damage occurring, diminishing their efficiency compared to conventional cables or wireless charging mats.

Conversely, wireless charging mats provide a slower and more measured alternative, distributing power through magnetism.

Many wireless charging mats provide power at just 7.5W, while the new Oppo Ace 2 accepts 40W charges.

Higher wattages increase heat transfer, so it’s best to use Qi wireless charging mats, which are limited to 15 watts.