Basically what the title says. Why is it that no one has come up with a solution to try and charge things such as phones through wifi/bt? I know entirely wireless charging exists in some form, but what makes it challenging to make it up to par with normal charging speeds?
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Let’s look at Bluetooth.
Bluetooth can transmit at around 100 mW (20dBm) max.
A nearby peripheral will generally see a signal of around -35 dBm (relatively close).
-35dBm is around 3E-7 W.
Your iPhone 13 has a battery with around 12 watt-hours, so even if you had 100% conversion efficiency, that Bluetooth signal would only take 12/3E-7 = 40 million hours (4563 years) to fully charge your depleted phone.
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