StreamLight 4AA 7 LED with NiMhs..Mine died

I had my streamlight 4AA 7 LED for about a week and had been running NiMh batteries in it. I was extremely impressed with the light output. I ran it once strait for around 10-15 minutes and noticed it was getting hot. I took a look at the LED's and a couple of them had made it to the angry blue stage. I promptly turned it off and let it cool down. I used it intermittently a few times and all seemed fine. The next day my wife and I went out to dinner, and upon leaving I heard a klunk. She had brought the flashlight with her and it had hit the concrete pretty hard. The next time I used it one of the LED's was flickering, I turned it on and off a few more times and a second one started to flicker.

Anyways, I'm getting the light replaced. I'm unsure as to whether or not the LED's flickering was caused by the drop or simply that the LED's were getting too much juice from the NiMh's. Normal alkaline batteries actually had seemed a little brighter to me than NiMh's when I had tested them initially. I wanted to use NiMh's because I had been planning to use the 4aa as a walking light.

Can anyone here attest to whether or not NiMh's work fine with their SL 4aa 7 LED? If so, how long have you left it on for etc. I really liked the light R.I.P. Also if somebody has any experience with the 10 LED 3C streamlight with NiMh's please let me know.

Thanks.

I have seen that flickering failure mode with overdriven LEDs. This particular flashlight drives the **** out of the LEDs. There was quite a bit of discussion of this light in the following the following thread:
http://www.candlepowerforums.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=3;t=002885#000007read:

Elektrolumens has a discussion on his 3 cell (AA or D) maybe brinkman legend direct drive luxeon flashlights he sells on his website (taken from buy/sell forum under brinkman 3AA with lambertian ls for sale):

" quote:
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Originally posted by ChrisM:

quote:
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These are direct drive. NiMh's will fry the emitter. Not sure about Lithium's. I can add a resitor, but it's more work, so I would charge a little more, $65.

Wayne J.
www.elekrolumens.com
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Huh? If NiMh's are only 1.2v and alkalines are 1.5, why would a lower voltage fry the emitter?
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The only LS modified flashlights I've ever had returned for burned out emitters were used with rechargables. It took me a while, but I finally figured out what was going on. Even at only 3.6 volts, the current is too much for the emitter. Three AA rechargables will pass more current than three fresh D cell alkalines. The proof is in the puddin', burned up emitters.

The Lambertian's are consistently slightly bluish, and provide a tighter beam than the low domes when used with optics. Lambertians will also work with the stock Brinkmann 3AA reflector quite well.

I've sold over 30 of the Brinkmann 3AA mod's in the past. No complaints so far.

Wayne J.
www.elektrolumens.com "

Just for your information. All direct drive luxeon flashlights with 2 or less batteries will be disappointingly dim so stay away. The good ones are 3 battery direct drive luxeon stars but all are unprotected and you can't run them with rechargeables unless you special order a resistor to be built into it.

However, flashlights like lambda's illuminator and arc's ls which both utilize a DCDC circuit board with 2 batteries are nearly as bright as anything else and are supposed to be safe with rechargeables. Arc's ls is having a sale on seconds for 49 dollars right now. I heard people have problems with the cr123 battery pack; they need to place a spring in it to help with battery contact. But I use the 2AA battery pack and don't mess with the other one and I have no problems with either duracells or the shorter kodak 1850 nimh AA batteries I bought from thomas industries.
I love the ARC flashlight, get it(Ihave nothing to do with the company, I just like their product)

Also, as far as nichia based flashlights are concerned, I believe you can use the above discussion. Here is my observations on the flashlights I own (it's my own opinion and I'm not sure and please don't get offended for everyone has their own favorite flashlights). First ledcorp's pro3 luxeon star drop in bulb for maglites is supposed to have a resistor in it and my 4 cell version seems to work well with nimh but this bulb is not as bright as the arc ls. Lightwave I heard is supposed to build a resistor into their larger flashlights. My excursion pro has a resistor on it's 19 led board but the instructions warn NEVER TO USE RECHARGEABLES IN THIS FLASHLIGHT which is scary since it cost me $200. The eternalight is run from a circuit board and can handle lithiums so maybe ok with nimh. I don't think my turtlelights have any protecton but I use them with rechargeables awaiting the worst. Also, if you like turtlelights I heard that CYAN or AQUA GREEN led bulbs are supposed to be twice as bright as white nichia 5600's. Ledtronics sells a 3 led drop in flange bulb with these aqua green led's. This bulb is rated 30,000 mcd while their 3 white led bulb is rated 18,000 mcd. And the stock turtlelight II only comes with a 2 led white bulb which shines about the same as the infinity ultra with one bulb. I am waiting for my new aqua bulb in the mail and I'm going to place it in my turtlelight and other flashlights to see if there is a difference.

Finally, let me say that Arc's AAA in white or turquoise has a DCDC circuit board which should?? protect it from rechargeables. I heard that unless you get a bum led that the turquois should be much brighter overall. It just wont have as bright of a hot spot since it's lens shoots the beam over a 30 degree arc versus the 20 degree for the white led. So I bought the turquoise and am waiting. Also, I own all the infinitys. I like them because they use the AA. But, they have a different circuit step up which I don't like. The infinity flashlights step up circuit will dim just like a direct drive flashlight over battery life (some people may like this, everyone has their own needs in a flashlight). However the Arc's circuit is supposed to force the battery to put out peak brightness for the entire 4.8 hour burn time before dropping to a dim state. Also, for some reason 2/3 of the inifinity ultra's I bought (yes I bought a lot this website has a bad influence on me) have very bad beam centerring. THe center hotspot of the beam is almost to the edge of the dim circle of the outer light ring. When I look at the bulb it's sticking out diagonally, not even visually straight. I wonder who's assembling these things. But, I haven't received my arc AAA yet so I can't vouch for them either. But I'm hoping that their quality of construction will be better.

I hope this helps you in your decision on what flashlights to buy for rechargeables. My final suggestions will be this. Stay with:
elektrolumens and order a special made flashlight for use with rechargeables from him not the stock ones he sells.

lambda illuminator or pill.

arc ls with 2AA battery pack on sale for 49$ without the pack.

arc AAA turquoise (supposedly turquoise is brighter) or le white.

The following are risky (I don't know because my tektite excursion pro scared me because it has a resistor but still is warning not to use nimh):
lilghtwave, ledcorp luxeon drop in, eternalight

I just read on the arc forum that gransee from arc is making this wednessday the final day of the $49 ARC Luxeon Star hybrid sale. Get it now before it's gone. Most of the time when I logon to websites with good priced flashlights they're all sold out or not offered at this time. So to with arc seconds until just recently. Here are the websites for the best for rechargeables just remember not to order an elektrolumens without having him special build it for $10 more.

http://www.elektrolumens.com/4_SALE/For_Sale.html

http://home.mchsi.com/~lambda/lambda3.htm

http://store.yahoo.com/flashlight/closandspeco.html

http://www.tannersstorefront.com/ledtronics.htm
http://www.safetyled.com/safetyled/ds/9&15mm_flashlight_&_task_light_led_lamps/112.htm

http://www.ledcorp.com/

http://www1.ecxmall.com/stores/texastacticalsupply/Detail.bok?no=95

This company has some neat products but I recommend staying away from the 2AA flashlghts since I don't like dim stuff. They have good bright lights however just not the 2AA. Get CYan for maximum brightness. Better to buy assembled than to do it yourself (no mismatch filings or slight bumps to overcome let them deal with the headaches). However I HAVE NO IDEA IF THEIR FLASHLIGHTS WILL FRY THE EMITTER WITH RECHARGEABLES OR NOT. MY GUESS BASED ON A DISCUSSION I REMEMBER ON CANDLEFORUMS ON THE SUBJECT IS THAT THERE IS A VERY GOOD CHANCE THAT RECHARGEABLES WILL FRY THESE FLASHLIGHTS. YOU'D HAVE TO HAVE THEM BUILD YOU A SPECIAL ONE LIKE ELEKTROLUMENS DOES. But these are the brightest flashlights available. Recommend the collimated trilight or helios (assembled only and in cyan or the dimmer white).
http://www.inretech.com/adapters.htm
http://www.inretech.com/helioswhite.htm

Also you like rechargeables how about lithium ion rechargeable flashlights:
This one uses sony's top lithium ion camcorder battery pack shown on left
http://www.onecall.com/PID_16712.htm

This one uses a cheaper lower capacity custom 2 dcell size I think battery. You can plop into your other 2 d flashlights that can contact a flat nipple less battery (I think lookingat picture):
http://www.aspencer1.com/showitem.asp?ItemID=11061.32

Thanks for the suggestions. However, I'm really interested in getting feedback from others with SL 4AA 7LED lights as I'm not sure if I should say that this light was indicative of all SL 4AA 7 LEDS or perhaps this one is just a fluke. I seriously like the light and I'm willing to give it another chance. At night it would light up my entire living room offering a very wide and usable beam. It sounded like quite a few people on the forum bought this light and I'm genuinely interested if their flashlights are still alive and kicking, especially if they used NiMh's. I really dont know if it was the hard drop on concrete that did the flashlight in, or if it was the NiMh's.

The electrolumens light sounds like it might be up to the task as a walking light, I just have no clue as to how wide of a beam you can make it go. If it could put the streamlight 4aa to shame, I'd be very interested.

I also have an LGI on order which is going to be my first luxeon..yay I dont want to risk using NiMh's in it though.

I've seen other posts in the LED forum that suggest that this light should be used ONLY with alkaline batteries (there's even a mention in the packaging about this).

One post on the LED forum said they fried their 4AA on lithiums.

I really like the idea of using NiMH as the routine battery source but I've only seen two LED lights where people are running NiMH routinely; the Opalec Newbeam and the PT Attitude.

I have the PT Attitude and use it with NiMH and it seems to be working just fine.

Moved to LED forum

I have this light, and have only used it with alkalines. For me, it's the light I keep in the glove box, specifically because I don't have to worry about a bulb burning out. For the same reason, I don't use NiMH's (2 week charge time is lousy.)

However, I've read the posts about lithiums, and it makes sense that NiMH's wouldn't work. The light is very high current, and non-regulated, so it's depending on the internal resistance of the AA's as part of the current limit. NiMH's have very, very low series resistance, so they probably are operating at a higher voltage under that load, and freaking out the LED's.

StreamLight has a lifetime warranty, though. I'd be interested to see what they say. (My bet is that they replace the light, and ask you not to use rechargables in it any more.)

If you're stuck with rechargables, I'd suggest the newbeam conversion in a mini-mag. I love mine. Not as bright as the Streamlight, but regulated, so it'll run fine on anything.

I'm probably a snob about it, but I don't want anything to do with Luxeons (spelling?) until they get their act together w/ production. Too many stories about bad colors, and "luck", and "you take what you can get". Well, I choose to vote with my wallet on that one.

Originally posted by Albany Tom:
...rechargables, I'd suggest the newbeam conversion in a mini-mag.

Click to expand...

<font size="2" face="Verdana, Arial">The Opalec/NiMH combo does get high marks.

Originally posted by Albany Tom:
...I don't want anything to do with Luxeons (spelling?) until they get their act together w/production. Too many stories about bad colors, and "luck", and "you take what you can get".

Click to expand...

<font size="2" face="Verdana, Arial">I feel the same way about the Luxeons...I'd like to have one, but don't want to buy 10 just to find a good one. I'll wait...

Then you should buy from Mr Bulk or Lambda when they offer their conversion which are usually based on select Luxeons.

- Vikas

I'm glad that I was tied up on testing different LS lately and delayed my plan on SL4AA LED w NiMH.

Alan

Well now I'm bummed out, as I was planning on buying either the 4aa or the 3c led streamlight, in the near future.

Raven

If you concerned about the durability of the SL 4AA LED, mine has survived a number of falls to pavement, concrete, and bare floor without mishap.

I run mine with alkalines. Its been my walking light for about a month with the same batteries. I have no problems with it. I was bored one night and started throwing it across my yard and my dog would get it for me. She never really bit it because it is not dented yet, but still works good as new.

Raven, dont take it the wrong way. The sl4aa 7 LED light is a great little light. Its nice and compact, its got a nice clickie on/off button and puts out a pretty phenomenal flood of light for its size. I think we just have to accept that its not NiMh friendly. We should look and see if there is room enough to insert a resistor so it can properly handle NiMh's. I will have to wait until I get my replacement before I can look into this.

If some electronics guru can help figure out what would be the optimal resistance to use it would be appreciated.

R=V/I

4x1.4v NiMh's (1.4 fully charged).
7xWhite LED's running at ? mA. I believe I had read in a previous thread that it was 65mA. However in the head of the unit there are resistors for each LED.

Here is my most likely incorrect attempt.

R=V/I
R=5.6/.455 (which is 7x65mA).
R=12.3 Ohms? But this does not take into account the existing resistors..

Originally posted by LoneRebel:
If some electronics guru can help figure out what would be the optimal resistance to use it would be appreciated.

Click to expand...

<font size="2" face="Verdana, Arial">For your initial voltage of 5.6, if you want to limit the current to each LED to 30 mA [this is the manufacturer's "absolute Maximum rating"] add about 7.5 ohms in series with the entire module. This value takes into account that each individual resistor is already limited by a 12 ohm resistor. Expect around 8 hours runtime from NiMhs in the range of 1600-1800 mAHr capacity.

I remember a similar discussion on a similar thread regarding 3 AA alkaline vx 3 AA NiMh to drive a well heat sinked (sank?) luxeon. With the alks, it was fine, but with the NiMh, although lower voltage, the current delivered is far more devastating. Remember the internal resistance of alks to be HIGHER than that of NiMh cells. Conducting similar experiments, I can definitely vouch for that as well. I have fried a good lux, well heat sinked (sounds weird, is it sank?) on just three AA NiMh cells. They get "angry blue" pretty much within the first 10 seconds of operation.

Ed.

Thanks Doug, I'm kind of baffled though by your numbers. Please put up with my beginner level of electrical knowledge but by plugging in your resistance of 7.5 added in series with an existing 12 ohm resistor that would give us a total of 19.5 ohms and when plugged into the formula to find current..

We get..

I=V/R or 5.6/19.5=287 mA
when divided by the number of LED's which is 7 we get 41mA per LED which is above your 30 mA maximum rating. If you can correct my logic or lack of logic I'd appreciate it

Originally posted by LoneRebel:
Thanks Doug, I'm kind of baffled though by your numbers. Please put up with my beginner level of electrical knowledge but by plugging in your resistance of 7.5 added in series with an existing 12 ohm resistor that would give us a total of 19.5 ohms and when plugged into the formula to find current..

We get..

I=V/R or 5.6/19.5=287 mA
when divided by the number of LED's which is 7 we get 41mA per LED which is above your 30 mA maximum rating. If you can correct my logic or lack of logic I'd appreciate it

Click to expand...

<font size="2" face="Verdana, Arial">Sure. The objective is 30 mA/LED and 210 mA total. The battery voltage is 4 X 1.4 = 5.6. Assume the drop across the LED is 3.6V. This is the "typical" value from the datasheet. This means that (5.6-3.6)=2.0V must be dropped across the resistors. The individual 12 ohm resistors will drop 0.030 X 12 = 0.36V. That leaves (2.0-0.36)=1.64V to be dropped across the resistor to be added. Since all 210 mA flows through this added resistor, its value is 1.64V/0.21A= 7.8 ohm. The nearest standard resistor values are 7.5 and 8.2. Take your pick.

Thanks Doug...You da man!