Caution About Not to Use NiMHs in Flashlights?

[Boris_yo]

Hello. This one I didn't know. This is the caution I have mentioned on the back of Panasonic eneloop batteries charger:

"Do not use in water proof flashlight or any device with an air tight battery compartment"

What exactly defines flashlight with air tight seal?

I have Coastal HP1 flashlight and old Chinese SIPIK flashlight. I always used NiMH batteries in them. Coastal flashlight has rubber ring on its cap while SIPIK does not. I also have mini MAG Light with rubber ring on its cap but I have lithium AAA in it. I used to put AAA NiMH in it.

 

[alpg88]

pay no mind, no one on this forum, or other forums that i know had any problems using nimh cells in any light. they just cover their a$$es with such warnings for 1 in a billion case of cells malfunctioning and emitting gas. btw good dive lights have pressure release valves

 

[Monocrom]

Likely just lawyer-speak.
Such lights are only useful to the professionals who need them.
Very specialized. Other than being waterproof, they offer zero advantages to other lights.

 

[fivemega]

They are trying to cover their back just in case anything go wrong.
However, this could be an issue when it comes to submersible water tight flashlights for diving.
Rechargeable batteries can behave differently under higher pressure.

 

[bykfixer]

An air tight seal is one that has an IP rating with a number where you typically see the X (as in dust proof) since microscopic dust particles can get into places water molecules can't. IP68 for example. That and lights deemed intrinsically safe.

And like fivemega said lights under extreme pressure like dive lights at 2 or more atmospheres.