I've had my BV8000 for nearly a week, and I like everything about it, except the battery drain when the device is on standby.

With no apps open, and the phone used only to check battery level, its used 5% in under an hour since I unplugged the charge cable. I've updated to the latest official firmware.

I'd really rather like to keep the phone, but with the excessive battery drain, I fear I'll have to send it back. Is there a solution?

The issue is being studied by our tech team. Refer to this thread:
viewtopic.php?f=191&t=329113

If you don't want to wait for a fix, you can ask your seller for a replacement