I have a question about the specified runtimes of multi-level flashlights. The low level runtimes are often specified as being quite long, such as 36 hours for the Lumintop EDC01, which is a light that uses 1AAA. However, I’ve noticed that when used with a battery that is even at about 60% capacity, the light won’t work correctly. With mine, I can turn it on, but can’t change light levels. Sometimes I can change between medium and high levels, but can’t access the low level at all.
This doesn’t just happen with the EDC01, but also the Lumintop 1AA. I have both, as of just a couple days ago when I received them in the mail.
So anyway, how can the low levels of lights be so long if they cease to function when the battery starts getting a little low? How can they possibly be 36 hours (or even 60 in the case of the 1AA) if the low level becomes no longer accessible?
> when used with a battery that is even at about 60% capacity, the light won’t work correctly
what is the voltage of the battery when the light stops working?
how did you determine the battery is at 60% capacity?
> how can the low levels of lights be so long if they cease to function when the battery starts getting a little low?
a little low, as in, what voltage?
if you want to verify the runtime, you should install a fully charged battery, and leave it on until it turns off. Then measure the voltage, and note how long it ran.
I don’t have an actual volt meter, so I couldn’t tell you the voltage. I have an older battery tester with an analog needle. I estimate about 60% of charge because the needle moves up about 60% of what it does when a fresh battery is tested.
As for verifying runtime as you suggested, lights aren’t normally used that way. They’re turned on for a period of time when it’s in use, and then turned off. So if it’s turned off at around 60% of battery remaining and then the light is used again afterwards, it wouldn’t run at all as intended since the desired levels are no longer usable.
Either your unit is defective or nobody bothered to do extensive testing of the lower levels on that model.
Being unable to access the higher modes when the battery is depleted is normal behavior for many flashlights. If the lower modes are inaccessible sounds like a bug.
Your battery might actually be pretty empty! If your analog battery tester reads voltage close to linear, 60% from full (ca. 1.5V) could mean your batteries test at around 0.9V, which is pretty much dead for an alkaleak.
Does your battery tester has any information on how to interpret its measurements? I know mine does…
Anyway, it would be weird behavior for the light to work in medium and high but not low.
And if you’re using rechargeable NiMH batteries you can’t use the voltage reliably to estimate the state of charge because the discharge curve is rather flat. When the voltage starts to drop noticeably, the battery is more or less empty.
It runs perfectly fine on a fresh battery.
The question I had is what good low levels are (being so long, as advertised) if they no longer work when they’re needed most, which is over a long period of time.
I can confirm this behaviour with alkaline batteries ,my kids have some of my lights (only with AA, no Lithium for them!) But i also have to agree with John.
You cant say anything about it when you don’t have exact numbers.!
(Usually the batteries are fairly empty when this behaviour starts)
Faulty assumption - 60% charge on a NiMh. There is no accurate way to tell WHAT the actual level of charge is on NiMh. You can to some extent on alkaline.
More light means more draw. On an attempted higher discharge level, with a partially discharged battery, the light circuit may not allow it to go into a higher level.
You really don’t have any reliable or decent way to figure out the answer to your question.
I keep some older, low capacity, and hopefully not dangerous batteries around. They are good for doing low voltage cut-off or finding out there is none. This works better with lithium batteries where there is a rough correlation of voltage with capacity.
It’s more challenging to do some of that kind of investigation with NiMh.
As suggested, you put in a fully charged good battery, then stare at it for hours as it winds down and shifts levels. Pretty tedious, so much so that I often miss when it happens anyway.
Exactly where it shifts can be time measured, but it’s harder to tell the capacity remaining from the voltage at that point. Manufacturers……may……give you some guidance, but it’s usually pretty rough. Some of the best we get is from reviews in BLF.
Would the draw be dependent on what kind of LED emitter I have? When I ordered it, the website said it has a Cree XP-G3 in it. But when I got it and looked at the instructions, it says it has an Osram LED.
I repeat, this behavior is not expected. What I could expect is that the high modes will stop working when the battery is depleting, so instead of low, medium and high you are left with only low and medium or only low.
Are you sure that the ‘not-low’ mode is actually brighter than the low mode?
