Testing phone before finishing the repair.

I am currently trying to fix an iPhone 6 that has a shattered screen and is physically bent. The internals of the phone seem to be working fine. The front and rear cameras work besides the cracked glass. The fingerprint reader is in good shape and the phone responds to touch right away. I chose to order a replacement back, LCD display assembly and battery. Is there a safe way to test the phone before installing the adhesive strips on the back of the battery. If something was damaged on the logic board during reassembly I want to be able to return the brand new parts. Is the only safe way to place the battery in the phone without adhesive strips and close it up completely? I know the connectors on the logic board are quite delicate so I would rather not open and close the phone multiple times.