A hack to make AAA batteries work in AA slots is again surprising internet users.
A number of TikToks have shown just because you've run out of AA batteries doesn't mean you have to stop using battery-powered devices.
One TikTok shared by James Hawkins last year, which is now getting attention across British and Australian press, shows him using tinfoil and AAA batteries to get a clock working.
In the video, Hawkins shows a small AAA battery in a larger AA battery slot. He rolls up some tinfoil and puts it alongside the battery in the slot - and hey presto, the clock is working.
"Why did I not know this?" said one person.
"OMG all these years and it was this easy," said another.
Others were concerned the hack could be dangerous, but The Sun, which called it a "genius hack", spoke to a product safety engineer who said there is little risk to personal safety. However, he did say it could damage the device.
"Due to the low voltage there is little risk to your personal safety but those using foil to cut corners risk damaging their product and being out of pocket in the long run," Giuseppe Capanna, product safety engineer at Electrical Safety First, told The Sun.
"If aluminium foil is in contact with the copper or brass spring terminals of the device, it is likely to cause corrosion and eventually stop the device working altogether.
"Always follow the manufacturer's advice in relation to the product."