Danger in 3D printing over a lithium ion battery So I bought a Lulzbot Mini a couple months ago and finally downloaded Ultimaker's version of Cura... Boy... have I been missing out...

One feature Ultimaker Cura implemented that I've been looking for is a "pause at z-height" feature ("post-processing tool"). I'm building prototypes of an electronics device, and creating two pieces that snap together looks a lot worse than printing a single piece. If I could pause my print, insert my electronics, and continue printing, my device would look a lot more professional (even if it took longer to make).

My one concern is the lithium ion battery. Right now I'm printing in TPU. With a heated bed of 40 degrees Celsius, and a heated extruder at 240 degrees Celsius, there seems to be a significant risk that the lithium ion battery reaches a temperature above 60 degrees Celsius (damaging the cell, causing a potential explosion). Granted, I am not sure what "60 degrees Celsius" actually means. It could mean only one part of the packaging needs to reach this temperature, or it could mean the entire LiPo's internal temperature would need to reach this. In either case, the numbers don't look good.

On the other hand, the heated bed surely doesn't need to remain heated beyond the first few layers? Additionally, I can create a "roof" for the LiIon battery that I can slip it under, providing some insulative TPU before the rest of the device. I think the print would happen safely like this, but obviously, an explosion would be really really bad. Like it would probably burn my house down, and I would be asleep when it happened.

Does anyone have any experience doing this?
Is there a way to turn off the heated bed mid-print? I guess I can insert a g-code line during the pause? Will this affect the remainder of the print you think?
Am I being paranoid? Can the extruder actually pass heat through a 1–2 mm of insulation and cause an explosion?
Anyone know how heat travels from the initial, liquid print material through the rest of the structure?

Any more advice or things I should consider before pursuing this?

A more specific pause type might be helpful, if anyone knows of any.
I would have to see your design to comment more but why not just change your model with the lid or top that can be either fused on later or attached in some other fashion? 

It is possible to turn off the heated bed after a certain layer. It looks like there is a discussion here with the G-code: Can Cura Turn Off a Heated Bed Partway Into a Print?

I would personally avoid exposing the battery to the heat generated by the hotend or the build plate. Printers alone can burn your house down. Why combine it with the awesome power of a lithium ion battery?