That is not how it should be, there may be a current leak other than through the driver electronics. I’m curious if others have the same observation. If this unexpected high drain is a general feature of the Q8 it is wise to physically lock out the light when not in use, which would be a pity because Tom put in lot of effort to make it so low.
I have a total of 6 Q8’s - most for emergency lights - we loose power often - all sit for months at a time without any unusual drain. They all have been in use since shortly after the group buy.
If you want to measure parasitic drain, you need a digital multi meter. You can basically do it like this:
Set your meter and test leads to milliamp. Then take a battery and touch the positive end to the driver ring, then attach the meter from the battery negative to the driver ground. You should be seeing about 0.12 milliamp with the side switch lights on.
If it’s way higher, then you have a problem with the driver or a short somewhere.
I would think heat would be the biggest issue since the clones don’t use a DTP mcpcb, plus the shelf are usually paper thin if it even has a shelf.
Check out this video David Sunshine did a while back. https://youtu.be/efl0R63-ik0 I think he piggybacked a new driver instead of swapping it. He has a lot of details.
What I’m wondering is how the battery got down below 2.8v. This is the cutoff voltage. The driver should not draw any power below 2.8v. If it did, something seems wrong.
Does only one of your three Q8s drain the batteries fast? Maybe it has a defect in the driver? I don’t know.
Doing a drain test might give some answers.
Maybe the MCU is not going to sleep after 6 seconds like it should? I’ll ask ToyKeeper.
Yeah, I guess that makes sense. You actually need to MCU to be operating and taking samples of the voltage in order to determine whether or not it’s above or below the threshold and that process is just going to create increased parasitic drain.
Mine was from the second batch (#501-1000), which had the first batch issues fixed. It has been working great since I got it, and it gets used quite a bit. In terms of sheer number of hours, it has probably been my most-used light over the past year, but I’m not sure if that counts since it’s a whole lot of candle mode.
Anyway, no issues at all. And the button LED has been on pretty much nonstop the whole time.
The MCU also has BOD (brownout detection) enabled, but that doesn’t activate until 1.8V. So, if it gets that low, it’ll shut the MCU off even more than it normally can. Which probably won’t have a significant effect on the parasitic drain.
But LVP (which shuts off at 2.8V) only works when the light is actually on. And it sounds like whatever is draining happens when the light is off. So get out a DMM and start measuring things. It’s probably a hardware issue.