Inon strobe - how is the water getting in?

I have an Inon Z240 strobe that is getting water in the battery compartment. I've checked all oring sealing surfaces and they look fine. The oring has been switched out for a brand new one and the water is still getting in.

2 floods, 2 different orings. Both orings look perfect and the installation was fine.

Is there any other way for the water to get into this compartment? Ie. not through the cap/oring.

Change the battery cap!.

I had a flood due to a partial circumferential crack in the root of one of the threads. When looking at it in your hand it is invisible; but when screwed down it opens to admit small drops of water!

Nice one. Thanks for the suggestion okuma!