Short answer: yes, in your carry-on, provided the battery is under the airline limit. It cannot go in checked luggage.
Here is what actually governs it.
The 100 Wh rule
Airline rules for lithium batteries are set by watt-hours (Wh), not by the size of the device.
Under 100 Wh — permitted in cabin baggage without needing airline approval. This covers phones, laptops, cameras and essentially every handheld red light device.
100–160 Wh — permitted with prior airline approval. Some larger portable panels land here.
Over 160 Wh — not permitted in passenger baggage at all.
Our device is 18.5 Wh, comfortably inside the first band.
How to check yours
Look on the device, the battery, or in the manual. If watt-hours are printed, use that figure.
If only volts and milliamp-hours are given, the calculation is:
Wh = (V × mAh) ÷ 1000
Ours is 7.4 V and 2500 mAh, so: 7.4 × 2500 ÷ 1000 = 18.5 Wh.
If a manufacturer does not publish either figure, that is worth noticing before you get to an airport.
Why not checked luggage
Lithium batteries are prohibited in the hold on effectively every airline. The reasoning is straightforward: a battery fault in the cabin can be seen and dealt with; the same fault in a cargo hold cannot.
This applies to spare batteries and power banks too, and it is not a rule that gets waived.
At security
Take it out of your bag if asked, the same as a laptop. Nothing about a red light device is unusual to a screener, though the array can look interesting on an X-ray. Keeping it in its case makes the whole thing quicker.
Practical notes
Pack it so it cannot switch on. Ours has a screen lock. If yours does not, the travel case does the job.
Check the destination plug. Ours charges from any standard USB source, so a cable and whatever adapter you already carry is enough — no wall plug needed.
Charge before you fly. Two hours of runtime on a full charge covers a week away without a charger at all.