My view on baggage is if I can't afford to loose something or something is sentimental, then it rides with me in the cabin. If it can't fit in the cabin then it stays at home. In regards to LiOn I'd check them in personally but as they're always powering something that I couldn't live without then they usually end up in my carry on. I also ensure I'm at the gate first so I'm guaranteed my bag will fit in the cabin. Only aware of one airline go guarantee your carry on will fit in the cabin so unless I'm flying with said airline, I ensure I'm at the gate first. However if your battery is in good condition then I wouldn't worry too much about it being in the hold but if that device is important for your work or your business then I wouldn't take the risk.