Sisyphus Industries has replied about power banks before but I don't have the links handy (search this forum and the reddit). It's very possible, and they have tried it, but the runtime is not long (on the order or hours or a day, depending on the size of the power bank). You just need a power bank with a voltage and amperage level that matches the power brick that comes with the mini.
Thanks dithermaster. I did see the post you are referring to but that was referring to a power bank external to the unit. I'm wondering if 1) there is enough space inside the unit to accommodate the power bank and 2) whether it could be permanently installed so that when the DC plug is connected to the Mini it could recharge the power bank within as well as power the unit. Cheers.
Hi Bruce. Thanks for the info. It occurred to me that you would need to directly access the power bank to physically turn it on or off and the only way of doing this would be to remove the glass top of the Mini each time. This would not be practical so the battery would be better off being kept outside the unit. With more and more electrical appliances having their own built in rechargeable batteries maybe this would be an idea for future development? Not a criticism just an idea.