Previously have not used GUMSTIX. 
I want to connect to the battery GUMSTIX. 
I do not know is Consumption? 
On stand by? 
In normal mode? 
When use the wi-fi? 
When use bluetooth? 

I will buy this https://www.gumstix.com/store/product_info.php?products_id=268 model. 
I hope someone knows the answer. 
Regards.