mini-Mag 2-AA LED - Concerned About Reliability?

The mini-Mag 2-AA LED is a great light just like all of the other Mag Lite products (in my opinion). However, runtime testing has uncovered the fact that the light abrubtly shuts down after about 4 hours (using alkalines). Apparently this is due to the fact that the batteries fall below the regulator's design voltage. This could be an issue if you expect diminished light output to be your indicator to change the batteries. There is no "moon" mode.

I buy LED lights for reliability and long run times. This is the only fault I can find with this light and perhaps I should stop my "whinning".

Am I out of line with this concern? I walk the dog at night (about 2 miles) and just don't want to have to carry a spare light just in case the mini-Mag shuts down without warning.

No, you're not out of line, but your conclusion may unfortunately have been influenced by postings on this site. Web forums do have a tendency to have members that are quick to second guess and criticize manufacturers when a product is not manufactured specifically to their exacting requirements. Such posts may often seem authoritative and may even appear to be knowledgeable. Every product is going to have some characteristic(s) that someone won't like, it goes back to that addage about not being able to "please all of the people all of the time."

Look at it from another perspective. If you had no exposure to this or any other flashlight site, and happened upon this issue of the light just shutting off when the batteries were diminished, would it still be as big an issue for you?

While all of my MiniMag LED purchases have been the 3 cell version, I still plan on picking up a couple of 2 cell versions to leave in a briefcase/laptop case, and I will most likely have alkaline batteries in those lights.

I agree, but at least a incad bulb will grow dimmer over time and you will know it's time to change the batteries. Of course, that incad bulb will stop abrubtly too if you drop the light, unlike an LED light. I guess there are trade offs for everything.

An incandescent light using rechargeable can be pretty abrupt about shutting down as well. That's more a characteristic of the power curve of the battery than the light itself. Generally with an incandescent like a SL20 or a Mag Charger, the light will dim and then just go out soon after it starts to dim. And it can be rather abrupt, especially if you're standing in the middle of a street directing traffic .

Ironically, the light just passed 4.5 hours with the 2500mah rechargeables (1.2v each).

If you're concerned about the loss of "moon mode", then stick a coin cell light in your pocket. It'll take care of you as well as "moon mode" would. Additional cells for backup, just in case, would handle your emergencie needs too. That's what flashaholics have been doing for years.

I've used rechargables in my black 2AA MMLED. The light like you said just shut down on reaching the voltage limit.

Perhaps someone will come up with a LED scale like the Incan. Rayovac 2D for the body or tail cap, to show the battery charge remaning level.

Quite amazing though no perceptible drop in output prior to complete failure.

Take a look at this:

http://candlepowerforums.com/vb/showthread.php?t=131898

Great info, I think there's been a few people looking for info like that.

Bmccue1964 said:

Ironically, the light just passed 4.5 hours with the 2500mah rechargeables (1.2v each).

Click to expand...

Take a look at posts 1 and 3 of this thread. MAY NOT ALWAYS WORK!
http://candlepowerforums.com/vb/showthread.php?t=132368

It is a good idea to always carry a backup light. Since I got caught with a dead battery in my Solitaire in the big blackout of Aug 2003, I carry backups on my kechains in addition to my goto EDC.

Panasonic sells 2-pak replacement batteries for their CD players with a nice plastic battery holder. Unfortunately the batteries are NiCD. I use the plastic case to carry spare batteries for my walkman but will also work for 2AA mags.

I use my Mag-Led at work.

I've been running nimh batteries.

I always have another pair of batteries with me. So if the light suddenly dies I will switch the batteries.

If I could only get a tailcap switch with an LED that could harvest the remaining juice in the batteries (for backup light), that would make the light trustworthy. Of course, in order to make that work, there would have to be appropriate resistance at the head end.

Id be a little concerned running nimhs in mine due to the threat of battery reversal, especially since it drops off fairly quickly. Or does the circuit work in a way that protects against that?

I haven't seen it happen. Is it an abrupt wink off, or a quick fade over a couple of seconds? The former could be pretty dangerous if you're in the middle of something. The latter would at least give you a second or two to prepare.
I think the ideal thing would be for someone to mod a two stage tail cap with a bettery indicator. But realistically, you're going to have a keychain light or some other backup with you in case you need to change the batteries in the dark. And I wouldn't attempt anything that could be dangerous with just the Minimag LED as my only light source.(I'd be hesitant to attempt anything dangerous with only one light source anyway.)

I wouldn't worry about battery reversal. The LED shuts down at a cutoff voltage that will pretty well eliminate reversal, unless you've got terribly mismatched cells in the first place.

Bullseye00,

It shuts down all at once.

Thanks, Bmccue1964.
From Roy's 2AA alkaline and lithium runtime graphs, it looks like the light would dim perceptibly a few minutes before going out, giving you a decent amount of notice. Looking at the birghtness level of the light, can you tell that it's getting dim and the light may wink off at any time within the next couple of minutes, or is it really hard to judge. I know the best way for me to tell would be for me to do it myself, but I haven't had the time yet.

Since your eye adjusts to the dropping output level you essentially get nop warning.

I have ran through a set of cells and POOF it was gone!

re: Since your eye adjusts to the dropping output level you essentially get nop warning. - I was afraid that's how it would be, but the graphs gave me false hope.

"Hey, who turned out the lights?" is the phrase that comes to mind!