Dorcy 9 Volt LED

[xxo]

Picked up a couple of these from Dorcy:

snaps on to a 9 Volt battery and uses 6 LEDs

The switch on the side turns it on an off and allows 2 mode choices high, where all 6 LEDs are lit and Low with only 2 lit.

The Specs say it is 40 lumens on high and has a runtime of 100 hrs. (presumably on low).

All in all seems like a decent low cost LED that runs off of 9 Volt batteries - fairly bright and throws a bit father than I expected.


https://www.dorcy.com/flashlight-wi...MInPW4o8m23wIVEFqGCh1Q2AOMEAQYASABEgIm7_D_BwE

 

[JerryM]

After reading your post I ordered a couple also. The brightness on low is about what my Fenix E01 is. That makes me doubt that it will run 100 hours on low, but I am testing it now.
Thanks for the info. I think it will be usefus. I remember that a hiker was out for a month or longer using a Paklight (I think) on low and never changed the battery. That light, however had a single led mode. They are also expensive.

Pakiight makes one which uses lithium batteries. I wonder if the Dorcy will run off that?
I have a couple of NiMh batteries which I am charging to compare with alkalines.
Jerry

 

[Lynx_Arc]

It may run 100 hours on low (2 LEDs) but that doesn't say it will be at full output probably only 10% of the output after that long (if even that). I have a cheap 9v light running a single LED and it runs a long long time off 1 9v depleted battery but dims continuously over time.
I have a 2AAA nimh light using a single LED that runs for weeks till the light is unusable and it does so direct drive. LEDs can be useful putting out a few lumens and the power required is miniscule enough to run a long time off very little current.
I've seen those 6x5mm block LED 9v lights on ebay for years but never bought one as they were too expensive and cheap looking to me for what you are getting. 5mm LEDs cost nearly nothing such that a 9v adapter like that should cost about $1 to make and sell but they want about $6 from china for them.

 

[JerryM]

I always thought they were too expensive, but 2 for $3 is down my alley. That includes batteries.
Jerry

 

[Lynx_Arc]

I always thought they were too expensive, but 2 for $3 is down my alley. That includes batteries.
Jerry

Looks like $3 each with Free Shipping but remember you have to check the Free shipping option otherwise it wants you to pay $7.45 for shipping 2 day priority. $3 with shipping IMO is a good price as it is half the price they are on Ebay from China.

 

[xxo]

After reading your post I ordered a couple also. The brightness on low is about what my Fenix E01 is. That makes me doubt that it will run 100 hours on low, but I am testing it now.
Thanks for the info. I think it will be usefus. I remember that a hiker was out for a month or longer using a Paklight (I think) on low and never changed the battery. That light, however had a single led mode. They are also expensive.

Pakiight makes one which uses lithium batteries. I wonder if the Dorcy will run off that?
I have a couple of NiMh batteries which I am charging to compare with alkalines.
Jerry

I was thinking of trying some of the Energizer Ultimate Lithium 9V's, but they are kind of pricey compared to the cost of the light. Same thing with the rechargeable 9 Volts since I don't have any of the rechargeable cells or a 9V charger. I see that Soshine makes a Li-Ion rechargeable 9V that HJK reviewed that looks good, I wouldn't buy one and a charger just for these Dorcy lights, but I am thinking of maybe getting one to play around with the adapter that I 3D printed to run 9 Volt batteries in my Nite Ized LED Fulton angle head light.

A potential problem with NiMh and lithiums in the Dorcy is that they might cause the LEDs to burn out or go dim if these lights depend on the IR of the alkaline cells to limit current.

 

[xxo]

It looks like this light is sold under a bunch of different brands, such as bell and howe "microbrite", "Blocklite" and sinoR "mini compact" etc. but at a higher prices than the Dorcy brand.

 

[Hondo]

I don't think the cell internal resistance is used to limit current to the LED's, since the voltage is so high that it requires a "buck" circuit to use the 9 Volt cell. I would also say that the only justification for a lithium 9V, which should work just fine, like on the Pak-Lites, is for storage/usage in extreme hot and cold environments. I've used a Safelight daily for over 12 years, and I only feed it old 9V alkalines that came out of smoke detectors. I still only change the battery once or twice a year. Seriously, if you are going to buy batteries for these, I would just get the cheap carbon-zinc ones, they still run a long time, are lighter and probably give more lumen-hours/dollar.

There used to be an electronic click switch version on the 'bay that you could get for around two bucks in multi-packs and was pretty nice, my friend got a bunch as gifts 2-3 years ago, and I still have mine. No sign of them any more, but some of those "Blocklights" look like they have a click button instead of a slider switch.

Gonna have to snag a few of these too, I'm a sucker for 9V lights, especially since I always have a pile of free batteries to use in them. I'm assuming they never ran a BOGO at $3.00, and that was when they were at $5.99, so basically the same deal. Can't get an alkaline 9V battery for $1.50!

 

[Lynx_Arc]

I don't think the cell internal resistance is used to limit current to the LED's, since the voltage is so high that it requires a "buck" circuit to use the 9 Volt cell. I would also say that the only justification for a lithium 9V, which should work just fine, like on the Pak-Lites, is for storage/usage in extreme hot and cold environments. I've used a Safelight daily for over 12 years, and I only feed it old 9V alkalines that came out of smoke detectors. I still only change the battery once or twice a year. Seriously, if you are going to buy batteries for these, I would just get the cheap carbon-zinc ones, they still run a long time, are lighter and probably give more lumen-hours/dollar.

There used to be an electronic click switch version on the 'bay that you could get for around two bucks in multi-packs and was pretty nice, my friend got a bunch as gifts 2-3 years ago, and I still have mine. No sign of them any more, but some of those "Blocklights" look like they have a click button instead of a slider switch.

Gonna have to snag a few of these too, I'm a sucker for 9V lights, especially since I always have a pile of free batteries to use in them. I'm assuming they never ran a BOGO at $3.00, and that was when they were at $5.99, so basically the same deal. Can't get an alkaline 9V battery for $1.50!

Actually the LEDs are pairs wired in series and probably just have a small resistor and take 30ma or so for 2 and 100ma for all 6. If this is the way it is wired then a buck circuit would probably not work well to drop 2-3v or less and with all 6 LEDs lit the voltage would probably sad to around 7v or so when new.

 

[Hondo]

I guess at this price it makes sense that they just use resistors to throttle current, which would still work for the lithium and NiMH 9V batteries. I'm a bit spoiled in the 9V department with James' Safe-Light designs, which are quite sophisticated circuits. R.I.P. James Meyer, and the Safe-Light products.

 

[Lynx_Arc]

I guess at this price it makes sense that they just use resistors to throttle current, which would still work for the lithium and NiMH 9V batteries. I'm a bit spoiled in the 9V department with James' Safe-Light designs, which are quite sophisticated circuits. R.I.P. James Meyer, and the Safe-Light products.

They could also use a cheap linear regulator type circuit also that would probably add a little to the cost. I'm guessing the more expensive lights do have some sort of buck regulator and electronic switching circuit if they only use a single LED.
If these block lights don't have any sort of circuitry in them there is no reason they shouldn't cost but a dollar or two instead of $6 each.
Perhaps someone who receives one of these would be able to look and see what type of circuit they have etc.
An interesting experiment would be to get a 4AA battery holder with a 9v clip like attachment and see how it runs off 6v that would make for a lot longer solution. I have a 6AA holder that a 9v clip can attach to which would make for a lot longer runtime in a pinch.

 

[Hondo]

OK, got 'em already.

One had no stick on the glue holding the guts in the body, so checking out the board was easy. We won't count that as a defect, a little hot glue will put it into action.

They are slightly more complicated than I expected, but still seem to only use resistors to control current. But they have two different surface mount resistors, and three identical cylindrical ones. I can't follow just what they are all doing, but it works well. If I understood which does what, I would not mind adding resistance to the low, 2-LED mode, as it appears too close to the high 6-LED mode. It is brighter than my Gerber Sonic with a Nichia DS led, so the two LED's must be putting out about as much brightness, each, as the Sonic. High is mucho-plenty, and I would not touch it. Being shared by six LED's, I don't think each one is being driven too hard.

Another thing I anticipated was that it is just a little tricky to turn off, since off is in the middle of the switch, and you tend to sometimes go right past it to the other mode. I think it would be better to put OFF on the left, and low in the middle - but the switch contacts are soldered right into the PCB between the two banks of LED's.

So worth $3, since I'll put the new batteries in smoke detectors, and I would have paid almost that much for them anyway. And I'll run them on older, but usable 9V batteries, which I always have an over abundance of. Would be perfect if the low mode was about 1/4 of what it is, and the switch turned off at one end of its travel. But not really a great value for $6, IMO.

 

[xxo]

OK, got 'em already.

One had no stick on the glue holding the guts in the body, so checking out the board was easy. We won't count that as a defect, a little hot glue will put it into action.

They are slightly more complicated than I expected, but still seem to only use resistors to control current. But they have two different surface mount resistors, and three identical cylindrical ones. I can't follow just what they are all doing, but it works well. If I understood which does what, I would not mind adding resistance to the low, 2-LED mode, as it appears too close to the high 6-LED mode. It is brighter than my Gerber Sonic with a Nichia DS led, so the two LED's must be putting out about as much brightness, each, as the Sonic. High is mucho-plenty, and I would not touch it. Being shared by six LED's, I don't think each one is being driven too hard.

Another thing I anticipated was that it is just a little tricky to turn off, since off is in the middle of the switch, and you tend to sometimes go right past it to the other mode. I think it would be better to put OFF on the left, and low in the middle - but the switch contacts are soldered right into the PCB between the two banks of LED's.

So worth $3, since I'll put the new batteries in smoke detectors, and I would have paid almost that much for them anyway. And I'll run them on older, but usable 9V batteries, which I always have an over abundance of. Would be perfect if the low mode was about 1/4 of what it is, and the switch turned off at one end of its travel. But not really a great value for $6, IMO.

Thanks much for the information Hondo!

Any chance of a pic of the guts?

I thought the same about the switch, but it might not be bad to be able to select which mode you want it to turn on in from off. Also these don't look all that water resistant. One thing I would have liked is a way to attach a lanyard or a split ring to make it easier to carry.

 

[Hondo]

Oops, sorry, I already hot-glued it together. Something tells me after a good drop, the others may separate the same way - I think the hot glue treatment is a lot tougher than whatever clear liquid adhesive appears to have been used. Just don't let it get in the slot where the switch slides. For what they are, I was not going to invest much into modding one, but replacing a resistor would be within my skills and motivation.

Fun fact: After connecting a really sacked 9V, I found that low was brighter than high. When it tries to drive all six LED's from a weak battery, none of them are bright enough to let it match the brightness it can get from just two. So logically, at some point during the life of a battery, there will be a point where both settings are the same brightness. I kinda think though, that the 2-LED setting would be more efficient at that point.

The only way they are "water proof" is if the circuit still works when wet!

If I wanted a lanyard, I would wrap some light cord around the battery, leaving a loop or whatever you want, and squirt some Super Glue on the wrap to keep it from slipping. Batteries should last quite a while, but it would need to be done to each new one. Don't think that that head can't be knocked loose with a fair blow or a load from sitting down with it in your pocket. If it's loaded right, it comes off fairly easy, so I don't consider these the best type of light for EDC type use on your person. I see them more for nightstand, travel bag, by the computer, glovebox, kitchen drawer sort of duty. The Pak-Lite is only about half as tall as this thing, so it has a lot less tendency to get separated from the battery. The steel case of the battery will take a magnet, and then you can stick it on a fender or under hood for repairs. Of course, without any glue on the battery, the magnet will stay on the surface the light was attached to.

 

[xxo]

I was thinking or trying to drill a small hole on a angle through one of the corners on the back end for a small split ring, but you are right this would not make the best carry light.

 

[Lynx_Arc]

OK, got 'em already.

One had no stick on the glue holding the guts in the body, so checking out the board was easy. We won't count that as a defect, a little hot glue will put it into action.

They are slightly more complicated than I expected, but still seem to only use resistors to control current. But they have two different surface mount resistors, and three identical cylindrical ones. I can't follow just what they are all doing, but it works well. If I understood which does what, I would not mind adding resistance to the low, 2-LED mode, as it appears too close to the high 6-LED mode. It is brighter than my Gerber Sonic with a Nichia DS led, so the two LED's must be putting out about as much brightness, each, as the Sonic. High is mucho-plenty, and I would not touch it. Being shared by six LED's, I don't think each one is being driven too hard.

Another thing I anticipated was that it is just a little tricky to turn off, since off is in the middle of the switch, and you tend to sometimes go right past it to the other mode. I think it would be better to put OFF on the left, and low in the middle - but the switch contacts are soldered right into the PCB between the two banks of LED's.

So worth $3, since I'll put the new batteries in smoke detectors, and I would have paid almost that much for them anyway. And I'll run them on older, but usable 9V batteries, which I always have an over abundance of. Would be perfect if the low mode was about 1/4 of what it is, and the switch turned off at one end of its travel. But not really a great value for $6, IMO.

I'm guessing the 3 cylindrical resistors are all the same value and are for EACH set of 2 LEDs and the SMD resistors are differing with one for the pair of 2 LEDs and the other either for the other 4 or all combined. If you hadn't put it back together you could take a resistor and parallel it across the other resistors and find which one does what when it gets brighter or not.

 

[xxo]

I tried hooking this thing up to some NiMh cells at 1.36V each, 4 cells lights up the LEDs very dim on both the high and low modes, while 5 cells lit them up fairly bright, so they won't vampire down to super low Voltages with much output. I would think that even a partially depleted 9V battery that is starting to chirp in a smoke detector would run these for a while but would probably be well below full brightness.

BTW it almost seems that they designed these to not be able to hook up to a 9V wire connector - the connections on the block are all recessed preventing the wire connector from snapping on all the way.

 

[Lynx_Arc]

Not surprising it won't run well around 5v as at that voltage a 9v battery is pretty much dead from my experience around 6.5v a 9v will cave in voltage a lot under even the load of an LED.

 

[Stormdrane]

I bought a few of them as well. They look just like the Blocklite. Cheap but functional.

And shown with an older two LED Blocklite and a Pak-Lite. For added functionality I stick a small powerful magnet to the battery, and if I need the light to be waterproof, I put it in a small zip lock type bag.

 

[Tesla]

I ordered 5 for various family. Are you the Stormdrane from EDC Forums, also?