The real reasons your phone battery is rubbish - and how to solve them

Stay charged for longer

Screen brightness

Battery life is the bane of smartphone owners everywhere. It's lovely being able to browse the net, play games, watch videos and update your status from everywhere and anywhere. But doing so too much can turn your phone into an expensive paperweight- at least until you get home and get it plugged in.

All is not lost though, as there are numerous ways to eke out a little (or a lot) more juice from your ailing battery. But there are tonnes of 'guides' telling you how to save your power - but very few ever bother to explain why.

What difference does having a bright screen make? Why do you need to turn off the buzzing? Should you be leaving GPS and Wi-Fi on all the time, or does it not really matter at all?

We spoke to some engineers from the big phone firms to find out the actual answers and give you more information on why your battery can inexplicably die.

1. Don't let your phone get too hot

You might have noticed that your phone gets hot sometimes. Assuming you're not in a volcano at the time this probably means your processor is being heavily worked by some rogue app and that increased workload will have a seriously negative effect on your battery life.

This isn't always avoidable, but if you're not sure what's causing your processor to work so hard check your task manager, in case there's anything clogging things up in the background and stop anything that looks a bit suspicious.

Beyond that, your phone's battery can get hot based on the surroundings it's in, so you can help it out a little by keeping it away from hot environments. That might mean not leaving it near a radiator or on the dashboard of your car, or near other electronics that are pumping out heat.

If a battery does get too hot (be it from heavy use or a warm environment) it can cause it to degrade faster and extreme temperatures can even cause the electrolyte in the battery to ignite, starting a fire (though this is really, really rare).

High temperature

In the short term, lithium-ion batteries like the ones found in smartphones can actually perform better at high temperatures, as the heat lessens the internal resistance,meaning the factors that slow the flow of current within the battery, such as the resistivity of the internal components along with ionic resistance caused during electrochemical reactions, is basically negated somewhat.

High temperatures can speed up electrochemical reactions, lessening this aspect of the resistance. However this also stresses the battery, causing it to degrade faster and hold charge a little less well.

But extremely low temperatures are also best avoided as they increase the internal resistance of a lithium-ion battery, by slowing down the electrochemical reactions, causing it to work less efficiently.

As such batteries that are especially cold are likely to see a decrease in performance, though cold conditions have no real long term effects on a battery, so it should return to normal once warm.

Generally there's only a significant impact on the battery if the temperatures reach fairly extreme levels though and many phones even have built in ways to combat heat. We asked a Samsung spokesperson about the effect of heat on their phones and they stated the following:

"Our devices have temperature controls built in to ensure that the device and the battery will never get to a detrimental temperature, so if the device heats up we can downscale the processor to reduce the temperature."

So you shouldn't worry too much, but if you notice that your phone is getting hot try to remedy it.