Is it okay to charge your phone or anything rechargeable overnight? Can you over-charge? Even when you're not sleeping, is it okay to leave a device in its charging station all day?
Many of us are guilty of charging the phone overnight, just to make sure your phone is at 100 per cent at the start of the day.
Your tablet or laptop is also likely to be plugged into the wall socket 24/7 for convenience's sake – whether or not the battery is depleted.
We don't think much of our charging habits until something drastic happens, such as a ballooned handphone battery or worse, a fire caused by leaving our personal mobility device or PMD to charge overnight as seen in news reports. After that the paranoia kicks in and you start to think about it.
Interestingly, the battery doesn’t stay at 100 per cent throughout the night. It will drop a little as the gadget uses a bit of power to keep it running in the background, according to a Time article. Every time there’s an energy dip, the charger kicks in and juices the battery back to 100 per cent.
Smartphones are powered by lithium-ion batteries, which work by moving charge carriers (in this case, lithium ions) from one electrode to another. The ions move in one direction when charging and in the other when discharging. For one, the lithium-ion battery that powers your handphone or laptop actually does not like to be fully charged, according to the Battery University website. In fact, the high voltage from a full charge stresses out the battery.
Each time you charge your phone, you’re killing the battery a little. And this applies to home appliances, too, from the expensive vacuum cleaner to the affordable electric toothbrush, as long as they are powered by lithium-ion batteries.
“Heat is the worst enemy of batteries,” according to Battery University, a repository of battery science information maintained by the battery-testing company Cadex. “Lithium-ion performs well at elevated temperatures but prolonged exposure to heat reduces longevity.”
So what about the rare occasion when lithium-ion batteries swell up like mine did? Is that caused by overcharging? No, the phenomenon occurs when the materials inside a battery have decayed or are subjected to stress or physical damage over time, according to the PC Mag website.
The compromised battery can't handle the uncontrolled energy coursing inside it during charging and, in turn, causes heat and gas to build up.
Generally, it's okay to charge your devices overnight. Other things that can also short-circuit these rechargeables, include the battery over-heating during charging or using an incompatible charger. If you're not certain about the reliability of your gadget, try not to charge overnight if you can. In fact, over-discharging or over-draining the battery is another issue and it may affect battery life much more.
Don’t plug it in to charge when it’s still 80 per cent juiced. Lithium-ion batteries hate to carry full charges. But don’t let it drop below 20 per cent either; the battery will need a high voltage to get back its charge – which also diminishes its capacity.