Prime Power Switching Adapter

[matthiaspaul]

(09-20-2015 02:51 PM)Tim Wessman Wrote:  Basically, *anything* that provides power from a usb port will work fine.

This would suggest that the Prime does never draw more than 0.5A, as classical non-PD- and -BC-aware USB 1.x/2.x ports would allow only up to 0.1A without negotiation and up to 0.5A after successful negotiation with the host. Negotiation, however, implies that the data lines must not be shorted, but connected to a suitable USB host instead (or it would require a "smart" charger actively emulating an USB host).

The manual states that a full charge of the 1500mAh battery takes about 4 hours. With some safety factor this would suggest a charging current of not more than 0.5A as well.

One open question is if the Prime is BCS-aware and charges faster when it detects a charging downstream port (CDP) or dedicated charging port (DCP) allowing more than those 0.5A.

Another open question is how long it takes to charge the Prime if the power supply would only provide the 5V, but neither emulate an USB host nor short the data lines. If in this scenario the Prime would still draw more than 0.1A (taking less than 15 hours for a full recharge), it would violate the USB specification...

Tim, can you confirm or deny BCS compliancy? I might have overlooked it somewhere in the manual, but if the Prime would be BCS 1.2 compliant, I suggest to explicitly mention it in the technical data, as it would be good advertisement for the device.

Greetings,

Matthias