sudomod

Assuming I had two balanced batteries in parallel attached to a 1000C, could I expect to run into any safety issues? I have 2 2500mAh adafruit lipos. I'd prefer to use these if possible instead of buying a new, larger battery.

If your batteries are correctly matched in resistance, and charge level, yes you can run them in parallel. Adafruit even sells pre-matched double and triple 18650 packs that work with the powerboost.

I ran mine parallel and they fit perfect in the case with hardly any modification. No issue charging and I think I get like 12 hours of out of it.

https://imgur.com/a/au0XO

https://imgur.com/a/RhlW3