It should automatically switch to battery when you unplug the USB. I suspect your board is initially defective. Wonder why Seeed has not commented on this issue! Why don’t you consider requesting a replacement from Seeed?
Hi, as the products we have on hand do not reproduce the problem you describe. So for issues that may involve the quality of the product, my advice would be to contact our technical support email directly and let our quality department assist you with the problem. Thank you for your support and cooperation.