I was going to suggest a lipstick battery, similar to what JackRussellRacing was using before switching to Wahoo. I have a flashlight holder with a GoPro mount attached to a K-Edge that I was using for a light, would probably work really well with a lipstick style battery. The way I have my 1000 mounted, the battery port should be easily accessable, but YMMV.
* There is a 70% chance that what you have just read has a peppering of cynicism or sarcasm and generally should not be taken seriously.
I'll leave it up to you to figure out the other 30%. If you are in any way offended, that's on you.