Got a tip for us?
Let us know
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
Wireless QI 7.5 charging question
- Thread starter Zaft
- Start date
- Sort by reaction score
I7guy
macrumors Westmere
Think you need the 3.0 but someone might chime in differently. Due to efficiency losses you need more than 7.5 watts.
TheIntruder
macrumors 68020
All the wireless chargers I've come across require a wall adapter capable of 9V or 12V output (...meaning QC) to charge at greater than the base 5W Qi profile.
5V can only go so far, and USB was only originally designed to support 500mA. It's been upped and cajoled over the years to go over 2A, but the voltage constant became a limiting factor.
Enter USB PD, which breaks free from that constraint (5/9/12/15/20V, up to 5A), but I've yet to see a charger specify PD instead of QC to satisfy the higher energy demands. Throw more coils into the mix and they go higher.
Should be interesting to see how many coils AirPower utilizes, and how much power it will demand. If it ever arrives.
5V can only go so far, and USB was only originally designed to support 500mA. It's been upped and cajoled over the years to go over 2A, but the voltage constant became a limiting factor.
Enter USB PD, which breaks free from that constraint (5/9/12/15/20V, up to 5A), but I've yet to see a charger specify PD instead of QC to satisfy the higher energy demands. Throw more coils into the mix and they go higher.
Should be interesting to see how many coils AirPower utilizes, and how much power it will demand. If it ever arrives.