What would happen if you accidentally, casually (because they're supposed to be so convenient!) put your apple watch on a wireless charger meant for phones or other higher power devices for hours? Or rather, what are the general things to take note of regarding compatibility of such wireless chargers?
closed as off-topic by JYelton, Hearth, Chris Stratton, Elliot Alderson, Dave Tweed♦ Feb 11 at 16:42
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "Questions on the use of electronic devices are off-topic as this site is intended specifically for questions on electronics design." – JYelton, Hearth, Chris Stratton, Elliot Alderson, Dave Tweed
In order to avoid wasting power, wireless chargers only activate when a compatible device communicates with the charger.
For major brands, compatibility will be a major thing, for example, if you put your apple watch on a non apple wireless charger, it's not going to charge. There may be some products that will charge from multiple wireless chargers, but this will not really be an issue.
The next thing is that the device to be charged is the one that has the charging circuit in it. The device will only draw the power that it needs. This is why an iPhone and an iPad can share the same charger, even though both require different amounts of current (or they did a few years back, I'm not too up to date with Apple any more!)
So in summary, you will be fine. If it is an Apple device, chances are it will only work with a compatible Apple charger. The charging circuit inside the device will only draw the power it needs to charge.
Most wireless chargers follow the Qi standard, which your Apple Watch doesn't, so no charging will occur. There's a complicated handshaking protocol to begin transmitting charging levels of power, so your Watch will only be subject to 60mW of ambient power. Whether that's problematic for the Watch hardware isn't something we can say for sure without access to a schematic, but it's very unlikely that anything negative (circuit damage) or positive (residual charging by accident) will ever happen.