This may not be the " brightest" idea but....

[vgdvc]

Hello. Well the opening tag kind of describes it but has anybody used two 2016 batteries stacked in place of a single 2032 to increase the brightness intensity on there red dot? I have tried it on my Romeo 3 in an effort to increase the brightness on sunny days especially shooting steel. It does help somewhat but I suppose I'm running 6 volts in lieu of 3volts and don't want to cook the internals. If someone with more knowledge (and more sense)would like to chime in please do so ,thank you.

[moparnut88]

That would be 6 volts if they are 3v each. Idk about that particular sight but I have had a few long talks with streamlight about their led technology. And they said their electronics can safely live on 36vdc but only normally run 3.6vdc. Now that is max capability but I'd say most well built circuits can handle some over volts without problems. My only concern would be heat.

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[vgdvc]

Thanks for the input. I would call Sig and ask them but I'm sure the overwhelming response would be "do not"

[Powder Finger]

Used to double volts on pdp2 & aimpoint never had trouble 

[ChuckS]

We did this on Docter sights that were slide mounted on open guns. It did work but that was with some way old technology. I am pretty sure it was all discrete electronic components. If the new sights are using any sort of integrated circuits, it is probably a very bad idea.

 

[gianmarko]

it all depends on what sort of technology is used to set the brightness

in the DDP, for example, the fact that brightness doesnt change with the charge level of the battery tells me there is some smart circuitry involved, possibly a buck converter  or other constant current step down regulator. and as there is for sure a microcontroller on board, its pretty safe to assume it is used also to drive the LED. 

 

red leds typically have 1.8 volts forward voltage, so a 3V battery is plenty to power it at maximum brightness. leds must be powered at constant current, so adding more voltage will not work 

moreover, leds are current regulated so adding more voltage to the input power will not change how the electronics will set brightness, except for  possible small changes due to the circuitry design

 

the slideride is completely analog, i suspect there is a simple limiting resistor inside the led module, and an external pot for setting up brightness. inefficient, but very simple and reliable. 

 

personally i would not stack two cells. it might not fry the circuitry, but it might indeed fry it. most microcontrollers are designed for 3.3 or 5 V,  therefore is safe to assume the MC used in red dots is of the 3.3 volts sort.

 

and even if by some quirk of the circuitry stacking two cells will increase the power current and led brightness, that might shorten the life of the led of your expensive red dot. there is no reason to think that manufacturers underdrive the leds, in fact, they might already overdrive them.. 

 

 

99% chance the brightness is set by regulating current, therefore stacking two cells will not do anything. 

 

lastly, coin cell batteries have pretty high internal resistance. that means they are unable to output high currents. in fact, it is pretty common to use a coin cell to test LEDs, as the coin cell sorta self-limit the current supplied and LED will not fry even powered at voltage higher than FV.

two smaller cells in place of a bigger one might make things worse in this aspect.  

 

 

 

[Hi-Power Jack]

You might want to see if there's another brand that is brighter.       

[BoyGlock]

1 hour ago, gianmarko said:

it all depends on what sort of technology is used to set the brightness

in the DDP, for example, the fact that brightness doesnt change with the charge level of the battery tells me there is some smart circuitry involved, possibly a buck converter  or other constant current step down regulator. and as there is for sure a microcontroller on board, its pretty safe to assume it is used also to drive the LED. 

 

red leds typically have 1.8 volts forward voltage, so a 3V battery is plenty to power it at maximum brightness. leds must be powered at constant current, so adding more voltage will not work 

moreover, leds are current regulated so adding more voltage to the input power will not change how the electronics will set brightness, except for  possible small changes due to the circuitry design

 

the slideride is completely analog, i suspect there is a simple limiting resistor inside the led module, and an external pot for setting up brightness. inefficient, but very simple and reliable. 

 

personally i would not stack two cells. it might not fry the circuitry, but it might indeed fry it. most microcontrollers are designed for 3.3 or 5 V,  therefore is safe to assume the MC used in red dots is of the 3.3 volts sort.

 

and even if by some quirk of the circuitry stacking two cells will increase the power current and led brightness, that might shorten the life of the led of your expensive red dot. there is no reason to think that manufacturers underdrive the leds, in fact, they might already overdrive them.. 

 

 

99% chance the brightness is set by regulating current, therefore stacking two cells will not do anything. 

 

lastly, coin cell batteries have pretty high internal resistance. that means they are unable to output high currents. in fact, it is pretty common to use a coin cell to test LEDs, as the coin cell sorta self-limit the current supplied and LED will not fry even powered at voltage higher than FV.

two smaller cells in place of a bigger one might make things worse in this aspect.  

 

 

 

Lots of info

Thank you

[vgdvc]

I appreciate all the input. Basic consensus seems to be it might work but at the peril of a $300 optic. Hmmm,been trying to avoid it but maybe I should just ante up and get a new 5moa SRO....

[Shmella]

There’s a lot of speculation in this post but it intrigued me enough to buy some eBay 2016 batteries and give it a  whirl. It made a huge brightness improvement for me. 

 

Nerds, do you really think this will fry my dot? The improvement in brightness I think would make a big difference on a  Bright sunny day shooting steel. Enough so that I may just take my chances at frying this thing. At least in low light conditions it seems much brighter.  Like glaringly bright. 

( I say huge difference but in reality it’s like %15-%20 brighter. )

Edited September 10, 2019 by Shmella

[WhiteDingo]

2 hours ago, Shmella said:

There’s a lot of speculation in this post but it intrigued me enough to buy some eBay 2016 batteries and give it a  whirl. It made a huge brightness improvement for me. 

 

Nerds, do you really think this will fry my dot? The improvement in brightness I think would make a big difference on a  Bright sunny day shooting steel. Enough so that I may just take my chances at frying this thing. At least in low light conditions it seems much brighter.  Like glaringly bright. 

( I say huge difference but in reality it’s like %15-%20 brighter. )

 

What dot are you using? If it's one with a lifetime/vip warranty, then I'd say try it for a while and see how it goes

[Shmella]

Same as op. Romeo3 

[Shmella]

40 minutes ago, WhiteDingo said:

 

What dot are you using? If it's one with a lifetime/vip warranty, then I'd say try it for a while and see how it goes

Same as op. Romeo3 

[gianmarko]

11 hours ago, Shmella said:

There’s a lot of speculation in this post but it intrigued me enough to buy some eBay 2016 batteries and give it a  whirl. It made a huge brightness improvement for me. 

 

Nerds, do you really think this will fry my dot? The improvement in brightness I think would make a big difference on a  Bright sunny day shooting steel. Enough so that I may just take my chances at frying this thing. At least in low light conditions it seems much brighter.  Like glaringly bright. 

( I say huge difference but in reality it’s like %15-%20 brighter. )

 

it really all depends on the circuitry, and some red dots cant even be opened to see whats inside, and check on how the led is driven. leds are funny creatures and a slightly lower driving voltage will cause a large drop in luminous flux, but a slightly higher driving voltage will cause a very small flux increase, a much larger current flow, and a much shorter life.  thats why they should be driven regulating current and not voltage. 

also, leds have funny ways of dying. one of the ways is much lower flux...

 

be aware that a 20% increase in apparent brightness most likely means a 100% higher current flow, and unless the led was underdriven to start with (and i cant imagine why any manufacturer would want to do that) that is a lot more current. 

 

all i can say is that the led of the slideride, the only one i have bench tested, depending on module and battery runs a 40mA current, which is pretty high for small red leds. so thats already overdriven. 

 

 

[Shmella]

I have 3 of these dots. I'll be the guinea pig without a brain. Worst case I burn one out.

 

The Brightness increase in one I tested was probably more like 10-15% but that was indoors so it may have been exaggerated. Ill test it outside in the sunlight to see if it really makes a difference. One of my R3's seemed brighter than the other two to start...

[lstange]

LED brightness is a function of current rather than voltage. In old red dots current is limited by a resistor connected in series. Doubling the voltage will double the current. Actually more than double, because LED is nonlinear and forward voltage drop on it remains about the same throughout its operating range. So you will see a brighter dot, but probably also reduce its lifespan. LEDs are not as picky as incandescent bulbs, but do burn out faster when too much current is applied.

 

In modern red dots there's a circuit that scans the buttons, reads ambient light sensor, checks movement sensor, monitors voltage and does all kinds of other things. To reduce losses it probably turns the LED on and off quickly, too fast for the eye to see. Judging by power consumption it's probably CMOS so chances are it's not that sensitive to supply voltage and can survive. Besides it likely sits behind some kind of voltage stabilizer. But if it's doing its job of keeping the brightness constant regardless of battery level, you should not see much difference.

[gianmarko]

someone mentioned finding an attiny13 in a red dot. attiny13 is rated from 2.7 to 5.5 volts, two new 20xx coin cells  would reach 6.4

 

"it probably turns the LED on and off quickly"

 

pwm. mmhh, maybe ill try to see if thats what is used in my DPP

 

 

[Shmella]

9 hours ago, lstange said:

LED brightness is a function of current rather than voltage. In old red dots current is limited by a resistor connected in series. Doubling the voltage will double the current. Actually more than double, because LED is nonlinear and forward voltage drop on it remains about the same throughout its operating range. So you will see a brighter dot, but probably also reduce its lifespan. LEDs are not as picky as incandescent bulbs, but do burn out faster when too much current is applied.

 

In modern red dots there's a circuit that scans the buttons, reads ambient light sensor, checks movement sensor, monitors voltage and does all kinds of other things. To reduce losses it probably turns the LED on and off quickly, too fast for the eye to see. Judging by power consumption it's probably CMOS so chances are it's not that sensitive to supply voltage and can survive. Besides it likely sits behind some kind of voltage stabilizer. But if it's doing its job of keeping the brightness constant regardless of battery level, you should not see much difference.

Well I’ll say this. A romeo3 is brighter with two 2016’s. I’ll take a pic to see if it shows up on my phone. I’ve never replaced a battery because it dimmed out so I can’t comment on whether it maintains brightness toward the end of the battery life. 

[gianmarko]

yup, the DDP runs the led in PWM. 

[gianmarko]

10 hours ago, Shmella said:

Well I’ll say this. A romeo3 is brighter with two 2016’s. I’ll take a pic to see if it shows up on my phone. I’ve never replaced a battery because it dimmed out so I can’t comment on whether it maintains brightness toward the end of the battery life. 

if the romeo3 LED is driven in PWM, as it probably is, then it makes sense as the pulses have higher voltage

all the considerations re voltage vs current and the possibility to fry the led remain valid.