Klarus Mi7 - Parasitic Drain Issues

Aloha Everyone,

I’ve owned a Mi7 for several months now. For a while, it was one of my EDC lights and for the most part, I was quite happy with it. I ran it with both AA NiMH and 14500. Prior to using it as my EDC, I had been using a Nitecore MT10a. I noticed that when I started carrying the Mi7, it seemed that I was having to change batteries quite often. Recently I’ve acquired a few more 1xAA lights and have moved the Klarus to my fanny pack, and that’s when I noticed something weird. The batteries I’ve been putting in the Mi7 only seem to last a few days before they are drained. I’m using Energizer NiMH batteries (hey, don’t judge), which last just fine in my other lights, but for some reason, the Mi7 drains them dry, even though I have the electronic lockout enabled. By comparison, I have a Manker T01 that I EDC and use every day with the same type of battery and that battery has been lasting weeks before needing replacement. Also, when I replace the battery in the Mi7, I perform a battery level check and it’s always registering 3 flashes before I enable the lockout on the Mi7.

Has anyone else experienced something similar or do I have a dud?

Mahalo in advance

Mine is still on its way…I hope it’s not normal in this light…I have stopped using my Nitecore EA11s because of that…horrendous parasitic loss, even when in locked-out mode…I don’t know why….and I have more than one EA11, all having the same problem. It has ruined two Sanyo 14500s already due to over-discharging. My Opus cannot re-charge it anymore.

My first 2 lights, the Zebralight SC600 and Klarus XT11, have been used very sparingly, its lone cell hardly re-charged for years, and I only knew how important it is NOT to have high parasitic losses after I have owned the EA11s.

So I have gone back to my beloved Eagletac D25A Ti as my edc light. It has mechanical switch, so no worries about losses.

I’ve not experienced parasitic drain that bad on the Mi7. However, most of the time I remember to lock it out physically by slightly unscrewing the head.

That sucks, tatasal. If this helps at all, I opted for the Nitecore MT10A over the EA11 and haven’t experienced any noticeable parasitic drain issues, I’m running a protected Xtar 14500 in it and regularly test the charge (love that feature). Current battery’s been in there about a month and charge is currently 4.0v. Maybe the EA11’s got design issues or you’re just SUPER unlucky? :cry:

I’m now opting for the MT10A over the Mi7 until I work out this issue. I’m also using physical lock out for the time being and the Mi7’s now a backup. If it turns out I have a dud, I’d love to order another, especially since they are now coming with clips, but if not, I don’t need 2 battery leeches. I suppose it’s POSSIBLE that the batteries I’m using are marginal, but I’ve been using them in other AA lights (Jetbeam MK 1, Xtar WK50, Skilhunt H15, Manker T01) and haven’t been experiencing any of the shelf life issues that the Klarus has been showing.

I just thought of something, My Mi7 normally resides in a fairly tight sleeve. I wonder if the button is being depressed while in the sleeve and if that is somehow compromising the battery life? Any thoughts anyone? Bueller? Bueller? Anyone? :wink:

In my opinion, parasitic drain is a very important parameter in buying/liking a light. This however, is often not tested in reviews. With a good design your batteries can last theoretically several decades, and with a bad design (as you unfortunately have noticed) your battery is dead in a couple of days. Interestingly, great scatter seems to be possible with parasitic drain as well. The tailcap of my two Lumintop SD75 (charging and USB out feature) lights measure 2 and 6 mA, even though Lumintop mailed me it’s supposed to be less than 1 mA.
I don’t think it’s a matter that the button may be depressed a bit; I suspect your light should just switch on then. If you have a DMM (or borrow one) you could check the drain current yourself. Cheers man!

Thanks for sharing this and sorry to hear your Mi7 OP.

*Not a good sign while waiting for mine to arrive. Really sucks if the parasitic drain on this flashlight is bad.

EDIT: Would love to know if anyone else have this same issue…

Oh man, I hate to hear this. Was just about to cave in and make an order, think I’ll wait a while and see if there is some more information on this.

I hope the op’s light is not common to all as hundreds of this light has been bought for months already and this is the first report of high parasitic drain.

Just received mine yesterday.
Hopefully it’s not a confirmed issues for all Mi7.

You’re very welcome. Thanks for your condolences. :zipper_mouth_face: Hopefully your’s will not have the same issue. With the number of Mi7’s already purchased, I’m sincerely hoping it’s an isolated incident. Over all, I really like the light. It’ll just be a bummer if I have to use physical lock-out to save my batteries.

I will start now a test, 2 batteries of my rotation for my 2xaa lights (same brand, lote and use). One inside one of my Mi7 (I have 3, I can do without it, for a while :slight_smile: ) and one in his box, in 15 days-1 month I will test the voltage.

(I do not use the electronic lock function, I prefer unscrew…I will try to test this in my next reviews)

One question for MKduffer, when you use the Mi7, you lock the light? seems yes. When you use T01 you lock…. ? I think is not possible…or perhpas you lock the T01 with mechanical lock (unscrew)?

Regards.

Maybe I’m missing something, but why won’t you just measure the standby drain current directly?

With my equipment, I can not give you a reliable measurement for this low currents.
But you’re right. Many people have this model. Can some owners give us their measurements…

I was pleasantly surprised to find out a lot of cheap basic DMM actually do have the ability to measure microA. More expensive DMM have like a 4000 or 6000 count ability. I personally think it’s worth getting a cheap DMM with this feature; it’s great being able to measure parasitic drain, especially after having experienced this phenomenon in an unpleasant way. Not to mention that if there is scatter, you will know for sure whether your specific light suffers too much from it.

Really is not a problem for me , I not use the electronic lock, I prefer unscrew a little the threads. (thanks for your interest:-)
Regards.

Hey Trevi_lux,
Thanks for doing the testing. Yes, I do use the electronic lock out on the Mi7. I haven’t needed to lock out the Manker as the button is recessed enough so that when it’s clipped into my pocket, it has never accidentally turned on.

BTW, I also have a Klarus AR-10 and Olight SR10 II. I use electronic lockout on both of them and have not had issues with parasitic drain. AR-10 had been in my backpack for several months and still has good battery life. The SR10 II’s been on e-lock for at least a month and still reading 4.04v in my charger (sorry, no DMM at work).

185 µA on my Mi7. So about 5 months to drain a 14500.

Thanks! Just wondering if it is plausible that you’re going to get a much different value when testing with NiMH. Obviously you will because the voltage is different, but perhaps the efficiency may be of a completely different order. With 14500 it’s 777 microW (=185 x 4.2), but is this the same with NiMH? Would you be so kind to test it with NiMH as well? Thanks!