If you want to charge your W810i, but are not interested in any connectivity at all, then this tip is for you. It is useful when traveling as the cable is lighter and more compact than the AC adapter. Plus, the cable also allow connectivity to your laptop should you need it.
1. Connect the phone to your PC (in my case, my MacBook)
2. The W810i will ask you to choose between “File Transfer” or “Phone Mode”, choose “Phone Mode”.
At this point, you might ask, “Why don’t I just connect it and charge at the same time?” My answer is two-fold. First, I believe the phone will charge faster without the connection to the computer. This is due to the fact that the phone will be in standby mode without the connection. Second, without the connection, you don’t have to worry about properly ejecting the device. Disconnecting the phone without a proper eject procedure might lead to data loss, or worse, malfunction.