Tiny laser batteries

[ElectricPlasma]

I managed to buy these three 14250s off of eBay, they're li-ion 3.7v batteries.

These are half the size of an AA battery, and when I saw them I got ideas for tiny laser builds. Here's an idea of the size:

Top to bottom: 18650, 16340, 14250

14250 vs 30mm module

A custom pocket build with one of these batteries with a <1W blue is something I have in mind. Maybe even something like an M462

 

[Deleted member 50194]

That would be kind of interesting to see! i find it awesome being able to have maybe 500mw of focused coherent electromagnetic energy coming from something as small as something you can put on a keychain. hope you find something awesome like that to make with them batteries

 

[Benm]

Such small batteries certainly exist. There is an even smaller 'standard' size: 10180, same diameter as an AAA cell but 1/3rd its length. Two of those in series could power a blue laser with a good linear regulator.

They will not power anything powerful though, better suited to the single mode diodes. The capacity is only 90 mAh or so, ruling out running 500 mW lasers as these are not RC batteries that can deal with being discharged in 5 or 10 minutes.

 

[ElectricPlasma]

Yep definitely won't be powering any nubm44's any time soon. Looking good so far though, one's been powering my 130mW 532nm module for almost 10 minutes now

 

[HydroSean]

If you look at the pics it says its 280 mAh. Since the capacitance isnt listed for this battery I would estimate the rating to be either 1C or 2C which means the maximum current draw would be 280 mA to 560 mA respectively. If I were you I would test one of them out at a 560 mA current draw just to see if it melts or not.

 

[Cyparagon]

A few minor corrections:

500mw of focused coherent electromagnetic energy

Milliwatts are units of power, not energy.

the capacitance isnt listed for this battery

Lithium cells do not have a capacitance rating, as they are not capacitors. I believe you're looking for the "discharge rating" spec. They also have a capacity rating in mAh or mWh.

If I were you I would test one of them out at a 560 mA current draw just to see if it melts or not.

Whether it "melts or not" is not a reliable test of discharge rating. Even if the cell were able to sustain this current without... melting, it may very well damage itself, leading to latent failures and/or explosions.

Of course, all modern lithium ion cells I'm aware of are rated for at least 2C. The question here would be if the 280mAh is an accurate number, as this is directly related to the maximum discharge rating at 2C.

 

[ElectricPlasma]

I doubt they're 280mAh only because of how much distrust I have for chinese "measurements". But, I got two of them to power my NDG700 which it's driver is set at 1.6A, batteries didn't get hot. I had it on for about 45 seconds and stopped, afterwards the batteries were completely fine only difference is one had dropped by 0.1V.

 

[HydroSean]

Lithium cells do not have a capacitance rating, as they are not capacitors. I believe you're looking for the "discharge rating" spec. They also have a capacity rating in mAh or mWh.

Yes I meant capacity of the battery or whatever refers to the "C rating" of a battery. I know you multiply the mAh by the capacity rating to get the maximum current discharge rate for Li-ion batteries.

I think its different for these new lithium manganese batteries that a lot of people are using in vaporizers which can handle upwards of 40 Amps pulsed. I just purchased a new top of the line vape which runs at 150W and 0.16 Ohms which is 31 Amps. I was stunned when the guy at the store told me these 18650 Li-MnO2 batteries can handle that amount of current draw when pulsed.

I doubt they're 280mAh only because of how much distrust I have for chinese "measurements". But, I got two of them to power my NDG700 which it's driver is set at 1.6A, batteries didn't get hot. I had it on for about 45 seconds and stopped, afterwards the batteries were completely fine only difference is one had dropped by 0.1V.

You had them running at 1.6 Amps!!?? Umm that kinda sets off a red flag in my mind lol

 

[ElectricPlasma]

You had them running at 1.6 Amps!!?? Umm that kinda sets off a red flag in my mind lol

Seemed fine to me. Though I did the test again and this time took the batteries out and they were noticeably warm (definitely not hot though), still not much of a voltage change. I ran it for about 25 seconds.

 

[HydroSean]

Seemed fine to me. Though I did the test again and this time took the batteries out and they were noticeably warm (definitely not hot though), still not much of a voltage change. I ran it for about 25 seconds.

Hmm maybe they are better batteries than expected? Totally ironic though and still seems fishy to me.

 

[ElectricPlasma]

Yes, I know my multimeter is wired backwards. Too lazy to fix it but you get the idea

Looks like it's doing 1.2 amps just fine. I guess the driver is ~1.2A then, I had thought I read on the website that it came set at 1.6A. But there it is, in the flesh.

Same result with the temperature, after a while the batteries get noticeably warm I'd say no warmer than a cell phone gets. I'll have to find my temperature gun.

And I haven't even charged these damn things yet in this test they're 3.8v and 3.75v.

 

[diachi]

A few minor corrections:



Milliwatts are units of power, not energy.

Being a tad pedantic with that one... It is energy whether you measure it in Watts or Joules doesn't change that. "500mW of electromagnetic energy" makes sense just fine. It's the same as saying "500mJ/s of electromagnetic energy".

 

[HydroSean]

Being a tad pedantic with that one... It is energy whether you measure it in Watts or Joules doesn't change that. "500mW of electromagnetic energy" makes sense just fine. It's the same as saying "500mJ/s of electromagnetic energy".

All three of you are correct, power is energy per second just like velocity is speed per second, while power is energy, energy isn't power. You can derive energy from power but you have to integrate energy to get power. And oooo pedantic I like that word

 

[Cyparagon]

What's the voltage under load, though? I bet that drops substantially. It may also explain why the current draw is only 1.2A instead of the expected 1.6A.

It is energy whether you measure it in Watts or Joules doesn't change that.

Energy is NOT measured in watts. Pick up a physics book; this is basic knowledge.

while power is energy, energy isn't power.

I don't think you both realize how wrong you are. You're saying Joules/second is the same as joules? Why do I even need to tell you this is wrong?

Distance is measured in meters, velocity is measured in meters/second, and acceleration is measured in meters/second^2. Do you also think distance is the same as speed? Or you Mr Sean. Are you going to try and convince people "speed is distance, but distance isn't speed"?

Sorry. I love you, Diachi, but this is f:undecided:cking laughable and I expect better of you.

 

[HydroSean]

Allow me to clarify because this is one of those times where calculus and physics get a little fuzzy with each other, like centrifugal or centripetal forces. The speed vs. velocity analogy is facile because speed is a scalar function and velocity is a vector function so it doesn't really relate to energy and power, but my point still remains true about what the power and energy functions are. Energy is a state function and power is a path function which means you can calculate the value of energy from a state of power but you need multiple states of energy to calculate power which is what I worded poorly earlier.

 

[ElectricPlasma]

Thanks Cyp, diachi and Sean for all the input. Aside from the argument I can't help but wonder why Cyp had to edit his post just to add "I love you, Diachi" but that's probably none of my business :crackup:

What's the voltage under load, though? I bet that drops substantially. It may also explain why the current draw is only 1.2A instead of the expected 1.6A.

Good idea, I'll have another test going once the batteries are charged.