nicklittle135
From reddit:
"Yeah, it's utterly beyond me how a company can fuck things up like this. This is a 250$ device, and they fail to allow charging while using, and they fail to provide a power adapter variant. It took me a whole 30 mins to add one myself, so yeah would it really have been too much to ask? If you gonna power this thing with a battery, at least install one that lasts for a couple hours...
As for how to add an adapter, it's pretty straightforward. I figured this all out myself and it's the first device I am modding... So be warned.
Open the front-lid... This is pretty easy, it is attached with 6 hooks that are placed equally spaced on the long sides of the panel. So take a thin instrument, like a screwdriver and stick it into the space between panel and case at the middle of the short edge. Slowly move it to the long edge where the first hook is, you can feel it becoming tight. That's where the hook is. Now gently rotate the screwdriver back and forth, like wiggling, until the hook pops out. The other two hooks are easy to undo, other side works exactly the same
Cut the battery off as close to the battery as possible and throw it into the batter disposal.
Get a 15V, 3A (or more) adapter from amazon. Cut the cord to remove the output connector and have a plain raw cable instead.
There is a small "airhole" over the motor opposite to the USB slot. There you can stick through the cable of the power adapter. You may need to gently widen the hole with a screwdriver or drill. The plastic thankfully is flexible and doesn't easily break, but rather falls apart where you drill...
Stick the adapter cord through the hole and then glue black wire to black wire and colored wire to colored wire (might have different colors, the black wire is the important one, only connect black to black). Tape it nicely with isolation tape.
Test the device by pluggin it in and pressing the power button. If should just work...
Now put the buttons back into the case. This is the most fickly part and I had to scream several times, but don't despair, it will work eventuall. The buttons need to be placed in the right orientation and it can take a few attempts to get them both working. Don't press the hooks back in until you are sure both buttons can still be pressed. For that press the case onto the device where the buttons are until they are in the right place and then test them.
Now close the case by pressing in all 6 hooks.
Give it a final spin. Everything should work.
Enjoy UNLIMITED POWER!!!"
I used this power supply kit, which lets you have a plug.
https://www.amazon.com/gp/product/B015H0UPWU/
I run it at 15v. I had read online that the battery is maybe rated higher than that, but if you try to run it at 16v or 17v, it caused the Kiiroo to freak out and shut off.
There are some other write ups online with pictures on how to do it also.