Left my P20 in the campervan with a fully charged battery (the supplied doubler), and just went to switch it on and it’s depleted beyond the point of switching on. I don’t have a tester to check whether it had anything left in it, but it’s pretty annoying to have a tool light like this not work when it’s needed.
Is this a known problem? I’m pretty sure I left it in lockout mode, it’s my default with most lights that go in storage so I know they haven’t got switched on and depleted.
Ok. Rather than delete and hide, I’m gonna take this one on the chin 
When I put a light into storage, well, a picture tells a thousand words. Or one one in fact, and that word is ‘idiot’. 
In order to distract a little, a D3AA arrived today with the 5000K SFT-25. Nicest using the standard optic, the throwy Carclo gives it a massive throw but it’s has a big ring and outer artifacts at closer ranges. Not an indoors light with that optic. All in all though, very impressive.
I was gonna say the P20 has a mechanical tail switch and should have zero parasitic drain.
@RichH you’re at your wits end… Until …you get to the tail end 
Im glad that you see the light… at the front end
Been a long day
I cant tell you how many times I was looking for my glasses when I was wearing them.
I’m glad (as I’m sure you are) that’s all that was the issue!
This light does have a parasitic drain. It went into my van fully charged, has been used once to show off while camping out with friends mid July. Grabbed it this evening to rush round to a friends house as she thought someone was shining a light around at the end of the garden (she’s nearly blind and was unsure, but scared). Acebeam P20 battery completely drained, I’ve just put it on the multimeter and it’s reading a flat 0.000 volts.
As pointed out, there’s a mechanical tail switch so I don’t see that it can be a problem with the internals of the light, but maybe this pesky Acebeam proprietary battery is draining itself?
Whatever it is, this light can’t be relied on in an emergency, precisely the reason I bought it.
Just to wrap this up, a new battery arrived today very well packaged from Acebeam, so many thanks to their customer service for sorting it out.
Old battery has sat in the light unused and fully charged. Put it on the meter and it’s down to 7.7v, so there’s definitely something amiss. Hopefully it’s within the battery and not the light, time will tell.
