Why you should never charge your phone overnight

A recent close shave brought home the fire-safety risks that come with our gadgets

It happened, like most accidents do, in a split second. One second the phone was charging; the next there was a spark from the cable and a small flame that had me scrambling to unplug the charger and hope that would stop it in its tracks.

Luckily, it did. If I hadn’t had the melted cable in one hand and a slight scorch mark on the other where I had been holding the phone, I might have thought I had dreamt the whole thing.

Even more frightening was the thought this could have happened while I was asleep. In recent months I’ve taken to charging my phone before I go to bed so I don’t have to leave it plugged in all night; that night, it was a 2am wake-up call that made me plug it in and discover the hard way that cables that look perfect aren’t necessarily safe.

We all have a couple of cables that we know should be binned, that are hanging on by some internal wires with the outer covering stripped away. Or the cheap cables bought as part of a special deal online because they keep breaking, so what’s the point in spending on expensive chargers?


Quite a lot, actually. Poorly made electronics such as phone chargers can cause electrocution or overheat and cause a fire, and have been blamed for a number of fires in recent years.

It is a risk now where 15-20 years ago it wouldn't have been an issue

The problem is that many people are unaware of the dangers, assuming that because the devices are on sale, they are safe. In Ireland, some of the responsibility for overseeing the safety of electrical goods falls to the Competition and Consumer Protection Commission (CCPC); anything that can be connected to the internet by wifi, Bluetooth or has an NFC tag – tablets, phones, laptops – is deemed radio equipment and falls to other agencies to oversee.

The CCPC works with the Revenue’s Customs Services on product safety, with the latter alerting the CCPC to consignments of products entering the country that may be of concern. In 2018, the agency examined 42 consignments containing more than 346,000 products, including toys, kitchen appliances, electrical adapters, chargers and hoverboards.

If you do come across a product that looks unsafe or appears to have a fake CE mark, you should report it to the CCPC

And while the dangers posed by hoverboard batteries catching fire may have been a headline grabber, the real danger can often be more mundane.

“Electrical adapters and chargers in particular would be an ongoing concern for the CCPC,” said Áine Carroll, the commission’s director of communications and policy.

There is good cause for that concern. Dublin Fire Brigade has taken to social media to highlight the dangers posed by such electronics, sharing some shocking photographs of the aftermath of fires caused by overheating chargers.

“We have been called to fires in bedrooms/livingrooms that have started due to charging portable devices,” explains Dublin Fire Brigade sub officer Darren O’Connor. “It is a risk now where 15-20 years ago it wouldn’t have been an issue.”

The issue may be more widespread than officially recorded though, because many of the incidents caused by phone chargers and cables – like my own – may be lucky enough not to require the fire brigade’s assistance.

There are some things you can do to lessen the risks. First off is to look for the CE mark on goods that you are buying.

“Certain types of products, including electrical appliances and products sold in the EU, must comply with specific safety regulations and must have a CE mark. The CE mark is a manufacturer’s declaration that the product complies with the safety regulations and the safety standards that exist in the EU to protect consumers,” says Carroll. “Always look for the CE mark when shopping for these products and if you can’t see it, don’t buy it.”

Of course, the mark can be forged. A genuine CE mark must be a minimum of 5mm high, the CCPC said.

For chargers, the CCPC recommends avoiding chargers that feel too light, are supplied with a two-pin plug or if the USB port is upside down. Labels that do not have clear contact details for the manufacturer or misspellings on packaging are also a red flag.

O’Connor says one of the biggest risks is people using non-branded chargers and cables, which are possibly counterfeit or poorly constructed.

“Branded equipment is CE compliant and has the components necessary to carry the correct current for charging the phone it is designed to go with and in the event of a failure carries internal fusing and overheat protection,” he explains.

“The components are also secured against vibration and the mains voltage and low voltage sides are shrouded from each other to prevent against the possibility of electrocution.”

If you do come across a product that looks unsafe or appears to have a fake CE mark, you should report it to the CCPC, which can take action.

Manufacturers, distributors and retailers cannot import or sell products on the market that do not meet the safety standards in Ireland, and those who do breach these standards could find themselves in court.

“If non-compliant or unsafe products are stopped at the point of importation, the CCPC can have the importation suspended and the economic operators may be required to re-export them to the country of origin or to have them destroyed,” said Ms Carroll.

Have an escape plan and practise this with the children in the house and make sure all non-essential electrical items are switched off or unplugged before going to sleep

But O’Connor warns against a false sense of security among those using official kit. “Even branded equipment has a life span and needs to be used correctly and maintained,” he says. “Regularly we see evidence of misuse of cables that are no longer fit for purpose and these present the risk of arcing when the cores of the cables are exposed. A cable like this left under a duvet or pillow has the potential to ignite the materials around it. Even if we’re talking about top-of-the-range branded equipment, this is possible.”

No visible damage

In my experience, it was a fully certified phone cable from a reputable manufacturer that caused the problem, and there was no visible damage to the cable that would have indicated there was a problem before it caught fire.

It’s not just new technology that can cause problems though. How many times have you switched the dishwasher on and gone to bed? Or put the washing machine on before leaving the house? That one simple act could be fatal.

The worst incident he has ever attended, O’Connor said, was a fatal fire caused by an electric fire that was left switched on. The use of such heaters has fallen though, making it a rare occurrence. More prevalent though is the tendency to leave appliances working while we sleep, go to work and in general just get on with our day.

“More recently I attended a fire in which a couple who were in the process of moving into their house, left a dishwasher on and went to some friend,” O’Connor says. “We arrived after calls from the neighbours to find the kitchen well alight and the rest of the house completely smoke logged. All their belongings that they had newly bought were in the house and destroyed.”

Prevention is better than cure, but in the event that the worst does happen, Dublin Fire Brigade’s advice is simple. “The biggest advice we would give people is to have working and tested smoke detectors throughout the house, with a minimum of two, one on each floor level,” says O’Connor.

“Have a fire blanket or small suitable extinguisher in the kitchen and as a final check in the evening before going to bed close all the doors. This will protect your escape route in the event of a fire occurring and the smoke detectors will provide early warning.

“Have an escape plan and practise this with the children in the house and make sure all non-essential electrical items are switched off or unplugged before going to sleep.”

It might seem a little dramatic, but a few simple preparations could save your life – or someone else’s. Although statistics show deaths in domestic fires have fallen since 2017, more than half of those who are killed are over 65. So keep an eye on older neighbours and family who may not be aware of the hazards.

The non-compliant cables could draw too much power if plugged into your laptop, leading to fried circuits – and tempers – all round

The same goes for younger teenagers and children. “What I feel is worrying is that there are many children of all ages that have portable electronic devices, from tablets and phones to laptops, and some of the age groups may not fully understand the potential hazards and risks that exist through misuse or failure,” says O’Connor.

“In this instance we would appeal to parents and guardians to take a few minutes of their day and closely inspect the equipment, and in particular the charging devices and cables associated with them. Also talk to them and make them aware of the care that is needed when using whatever electronic or electrical devices they have.”

It's not just the risk of fire – although that in itself is enough – that people should keep in mind when buying new phone chargers or cables. Using bad cables can actually damage your devices. When USB-C first started to appear in phones and laptops, cables that didn't meet standards were being sold online, leading one Google engineer to wage a campaign against them. The non-compliant cables could draw too much power if plugged into your laptop, leading to fried circuits – and tempers – all round.

Things have improved but those early lessons should still be noted. As should some old sayings: buy cheap, buy twice. There’s no such thing as a free lunch. If it seems as if it’s too good to be true, it probably is.

At best, you could end up with a dead device or two. At worst, cheap electronics could cause a fire with a potentially devastating outcome.


  • Don't charge your phone overnight. If you must leave your phone charge unattended, put it on a non-flammable surface such as a kitchen worktop.
  • Use cables and chargers from reputable sources, preferably the original manufacturer.
  • Look out for obvious red flags, such as USB ports installed upside down, or chargers that feel too light.
  • Regularly inspect electronics and cables for signs of damage, and discard anything that looks damaged.
  • Install smoke alarms and test them regularly.
  • Have your electrical system at home checked periodically by a competent electrician, including checking the fuse board for loose connections.
  • At night, unplug any unnecessary chargers and other electrical products. Close doors downstairs; if the worst happens, that will help slow or contain any outbreak of fire and give you time to escape.