Flash light problems

I'm trying to find out if any can help me. I carry two lights for work as a firefighter/emt. My first light is a armytek predator x that is my primary light. I really don't have any issues with this light. My back up light is ether a Foursevens QT2L-X burst or an Eagletac D25LC2. The main batteries I use are Eagletac 16340 (the black ones). Last night I had to switch to my back up because I forgot to charge my primary. The Foursevens worked fine for about 2-3 minutes and then shut off I turned it back on and in about 1.5 minutes it did it again. I checked my other Eagletac light and it was doing the same thing. I'm not sure if I have a problem with the lights them selves or if it's the batteries. The only common variable between them is the batteries. They don't do this with regular primaries just the rechargeable batteries. I also have a total of six of he same 16340 and all of them do this. If any one knows something I don't or can help let me know. Thank you.

If the black batteries you have are protected (AW?) batteries, it could be that the current draw is increasing as the voltage drops and it's tripping the protection circuit. It seems crazy to me that either of those two lights are pulling that much current from the battery though.

Are you fully charging the batteries? What's the ending voltage when you take them off the charger?

Ya there fully charged when I take them off the charger. I use the nitecore digicharger D2. I'm not sure if this helps or not but I don't use this light very much it's just a back up. I check the batteries when I get off of work if I use it at all and make sure there topped off at a full charge. The battery states on the wrapper that they are IC protected 3.7 volt 750 mah li-ion rechargeable.

It sounds like the rechargeables have a memory issue from being charged up and not discharged. You can "reset" the memory by fully discharging the batteries for several cycles to "wipe" the memory

smokinbasser said:

It sounds like the rechargeables have a memory issue from being charged up and not discharged. You can "reset" the memory by fully discharging the batteries for several cycles to "wipe" the memory

Click to expand...

That only applies to nicad batteries. Nimh, lithiums, etc don't suffer from that issue.

jamesEMT said:

Ya there fully charged when I take them off the charger. I use the nitecore digicharger D2. I'm not sure if this helps or not but I don't use this light very much it's just a back up. I check the batteries when I get off of work if I use it at all and make sure there topped off at a full charge. The battery states on the wrapper that they are IC protected 3.7 volt 750 mah li-ion rechargeable.

Click to expand...

If you're only using them as back up lights, it could be parasitic discharge. Are these clicky or electronic switches?

GeoBruin said:

If the black batteries you have are protected (AW?) batteries, it could be that the current draw is increasing as the voltage drops and it's tripping the protection circuit. It seems crazy to me that either of those two lights are pulling that much current from the battery though.

Are you fully charging the batteries? What's the ending voltage when you take them off the charger?

Click to expand...

I have the QB2L-X (original version, without burst), and the original D25LC2. I would not recommend using a pair of 16340 batteries in either of them. I like to use a 17650 battery (Eagletac) battery in the QB, and a 18650 battery in the D25LC2, for much better run times, and fewer headaches (fewer batteries to charge, at one time).

I'm pretty sure the OP is referring to the Eagletac 16340 protected battery in the picture (far left:


Not my greatest picture, but...

You may want to top off your 16340 batteries, every month or two, even if you don't use them regularly, so they're at their peak charge, when you do need them. They're good quality batteries, and they should easily be able to keep up with your lights, unless you've already charged them hundreds of times, and they're not holding a charge as well as they used to; but cut-off after only two or three minutes, should not be occurring, even if that were the case.

Eagletac lithium ion batteries were the first nice (high quality) batteries I ever purchased.

Both of those lights have mechanical switches, so I don't believe there should be any parasitic drain to worry about - but I could be wrong.

How long have you had your 16340 Eagletac batteries? How often do you check your battery voltages, in unused lights? I only ask this because, if you're exposing them to more extreme operating temperatures (severe cold, especially), they may not hold up/perform as well as primaries/disposables, when not used, for long periods. That's the lithium ion battery's one weakness.

The D2 is a pretty decent charger. I have a couple of D4s, and some other XTARs (VP2, VC4). They all work great. On my D4s (probably on the D2, as well), there's a setting (if you press and hold the Mode switch, while the battery's in it), that switches the charging circuit over, to accommodate a LiFePO4 battery, which charges at a lower termination voltage than regular lithium ion (ICR) batteries. If you managed to switch it over to that, your batteries wouldn't be getting the full charge they should be getting, but would look as if they're fully charged. That's the only other thing I can think of, with the charger, possibly being the issue.

this is a very interesting thread. Ive had the i4,d4 and now the excellent VC4. Sometimes Id get a 16340 that would only charge to 4.12 for some reason it became my problem cell. Add VC4 it charged all the way to 4.2 hmmmmm

Iv had these batteries for about a year and I'm kind of OCD when it comes to checking that there fully charged and topped off before every shift and while im at work. I think it might be that I'm charging them to much. I only use this light rarely when my main is dead or one of the guys with me dosent have a light I give it to them so it only uses maybe 5% of the battery between charges. Like I said earlier I use this for a back light for work. So it's exposed to temperature extremes. From structure fires to negative temps. When I get home tonight I will check the settings on my charger and check the voltage of the batteries.

Also my primary uses Eagletac 18650 3400 Mah batteries and I have no issues with them. Iv had them for about 2 years. These usually get fully discharged and then fully recharged on the same charger.

Have you tried using primary CR123 batteries? If the issue does not duplicate itself with primaries, then you've found the culprit.

If these are used as backup lights only, I'd put lithium primaries in them and call it good.

cland72 said:

Have you tried using primary CR123 batteries? If the issue does not duplicate itself with primaries, then you've found the culprit.

If these are used as backup lights only, I'd put lithium primaries in them and call it good.

Click to expand...

That it's the batteries, the charger or both?
OP does show he has no issue on primaries.

So Primaries are the answer?

WarRaven said:

That it's the batteries, the charger or both?
OP does show he has no issue on primaries.

So Primaries are the answer?

Click to expand...

My bad, I missed that he already tried the primaries and they don't exibit the same problem.

But yes, IMO the solution is primaries. No need in using rechargeables in lights you don't routinely use. As for his issue, I don't have enough know how to diagnose whether the issue is charger or batteries so I'll bow out of the thread.

If you use the lights rarely, you may be better off with lithium batteries (non-rechargeable).

1. They perform considerably well in harsh (hot and cold) environments.
2. They have a very long shelf life (10 years or more).

I keep primary batteries for back up to rechargeable in harsh weather. Canadian.
Though I think OP should investigate his root issue further.
Primaries have their place though, just I don't think is the answer here when op has already invested money to use his set up.

The Quark should work on voltage between 3.0v - 9.0v. So, it should be fine on both primaries and rechargeables. The fact that both lights are not working well with rechargeables, seems to indicate that it's weak batteries. Perhaps they've developed high internal resistance, and don't work well for very long at high drain.

Do the lights work properly at lower output settings? If so, that would certainly indicate high internal resistance.

Probably the elements (hot and cold) have caused the batteries to age quickly. Or, maybe they weren't very good batteries. (Fakes?)

Ditch the batteries and buy good quality replacements. Or, if you think the storage conditions are harsh, stick with primaries.

Throw the batteries?
You mean after he verifies with a DMM if,
they have power after being charged?

I just checked both lights. I let them run on high until it shuts off, turn it back on and it shuts off in about 3 seconds. When I switch it to low output they stay on and don't have any problems. It only happens on max output And i got the batteries from goinggear.Com (never hade any issues with anything i got from them). Idon't think it's the charger. I don't have the same problem with the 18650's I charge on it. The main reason I don't use primaries is that I tend to burn through 6-8 a week (that's with using my main light) so it's more cost effective to use rechargeable's. I think it might just be time for new batteries. I also checked the voltage on my charger and they read at 4.02 volts. The charger is set to the li-ion setting. If it is the batteries I think I might just get the AW 16340's and stop trying to keep a full charge on them as much.

Also I just tried them in a few older surefire's and the light flickers for about 20 second's then dies.

You didn't say how long they ran on high on your used carry lights, but if the older lights are dying fast,
Sounds about time as suggested, now, to replace them.. The cells.

I'm using some Olight RCRs and Nitecore, can't say a bad thing about them.
Olight might be slightly better outside wrapper, more durable.
Non of these cells in rechargeable format are higher then 650mah, don't be swayed by higher numbers. Though the AWs get a pass.
It's like the others but with known good builder behind them.

Let us know when new cells land and and you get to check them out. Have a great one.

Thanks every one for your help.

Sorry it's been a minute since I updated this. I had to order an emergancy dash light for my truck. I just got the new batteries yesterday (eagletac 16340). I charged them up last night and no issues with either light.
Thank you every one for all your help. I'll make sure not to charge these ones as much when I only use them for so little time. I'll wait until there closer to being almost dead from now on.