GPX6000 headphone charging indication

Just wondering if anybody knows why the manual states the LED red indicator goes out when charged.Both our headphones turn solid blue or sometimes blue and red flashing of which I have no idea.If I keep charging when alternating blue/red it never changes.Never had the headphones go flat and usually charge quickly to solid blue so no problems just confusing indications.

Deutran ,
Mines a solid blue when charged.

Mine flashes red/blue as if its charging, it never completes the charge cycle, they're just dodgy cheap Chinese headphones rebranded to be Minelab. it's random if you get a good set. Mine even have a constant hiss in the background when you're using them, in turn... I never use them.

I've worked it out.If you use them for only a few hours and charge the problem occurs.I now charge mine every second or third use and always stays solid blue when fully charged.Maybe Minelab should look into this.Yes there is definitely a hiss at times I thought I was imagining things because it comes and goes.