Many 3C product chargers on the market now use a design with metal contacts directly exposed for fast charging or to simplify the structure. They are very common from smart watches, wireless headsets, to game controllers. Although it is very convenient, this design actually has an important point of use. It must be kept away from metal objects, otherwise sparks are likely to be generated. Recently, a foreign netizen failed to notice that when the Pixel Watch 4 was being charged, the metal strap accidentally pressed against Valve’s Steam Controller Puck magnetic charging stand, causing a sizzling sound and almost catching fire.

The Pixel Watch 4 strap accidentally touched the Steam Controller Puck magnetic charging stand, causing an instant short circuit, causing smoke and almost causing a disaster
Recently, a Reddit user Toikka shared on r/SteamController that when his Pixel Watch 4 was charging, he placed it next to the Steam Controller Puck magnetic charging stand. The metal strap of the watch just touched the exposed contacts of the Steam Controller Puck magnetic charging stand. The metal began to make a sizzling sound due to a short circuit. He reacted immediately and pulled the strap away from the Puck, so it did not really burn, but both the Puck and the strap left obvious burn marks. He himself admitted compensation in the post, feeling that “the whole thing was my own fault.” He shared it just to remind other new players:

The Steam Controller Puck magnetic charging stand is an expansion accessory launched by Valve specifically for the Steam Controller. It not only has a wireless receiver function, but also has magnets inside that will automatically pull the handle to the correct position, and then charge directly through two exposed metal contacts on the surface. The advantage of this design is that the charging speed is much faster than purely inductive wireless charging such as Qi. The disadvantage is that the two contacts are completely exposed on the surface without any grooves or borders.
Therefore, as long as any conductive metal object happens to touch two contacts at the same time, a short-circuit current may form in an instant.
PSA: Watch out for the exposed contacts of the Puck! Almost started a fire due to metallic smartwatch strap
byu/Toikka inSteamController
Valve actually has a special warning in the manual. The Health and Safety Manual for the Steam Controller specifically states: “Magnetic parts may attract metal objects. To reduce the potential risk of sparks, property damage, or personal injury, please make sure there are no metal objects around the wireless adapter, charging base, and controller before connecting.”
However, for most players, they probably don’t know much about it and usually just leave it in the box. Even if you look at it, other people in the family and friends who come to play at home are even less likely to know that if you put keys, watches, and necklaces on the table, there is a chance that they will just touch the metal contacts of Puck.
Some netizens in the Reddit comments said that Valve did not design this part very well. The Xbox Elite charger has a raised design, and the Pixel Watch 3 charger is also made into a curved appearance to prevent people from accidentally putting things on it. On the other hand, in Valve’s Puck this time, the contacts are directly flat against the surface with almost no obstruction, which is why the strap can be pressed so easily:

Therefore, if the 3C product charger you have is designed with exposed metal contacts, you must pay special attention when using it. Toikka can only be said to be lucky this time. If he left directly to another room after charging, the consequences would be disastrous.

Source: KOCPC Chinese