Tiny laser batteries

[RedCowboy]

Joules includes the factor of time, watts alone don't. This is why your power bill is charged based on kilowatt hours.

It's like when people mix up nanometers that are a measure of distance between waves while frequency in hertz is waves per second.

What would a 532nm beam's frequency be in hertz?

You take the distance light travels in 1 second and divide that by 532nm of distance to get the number of cycles per second.


299,792,458 meters divided by 532 billionths of a meter.....dam, that's a lot of hertz.

lol this is messing with me, is it

5.63519658E12 or 15948958765600000 waves per second




-----edit-----

You may want to shorten those jumpers, they may be introducing some resistance.

 

[Cyparagon]

vector function so it doesn't really relate to energy and power

How about speed? Speed is distance per unit time. Power is energy per unit time. This doesn't mean power and energy are the same, and it doesn't mean speed and distance are the same. You're still trying to say they're the same, and they're not. Saying "500mW of energy" makes as much sense as saying "a distance of mach 1.2" or "a speed of 4 meters". I think the fact we're even HAVING this discussion is embarrassing.

but my point still remains true about what the power and energy functions are.

You still stand by "power is energy but energy isn't power"? This is categorically ignorant and logically fallacious. I could reference definitions, but I think you'd just double down about how the dictionary is wrong or some bullshit.

I can't help but wonder why Cyp had to edit his post just to add "I love you, Diachi"

Because Diachi is great and I didn't want it to sound too harsh.

 

[ElectricPlasma]

-----edit-----

You may want to shorten those jumpers, they may be introducing some resistance.

They're the only length I've got and I don't feel like shortening them, though you might be right.

Cyparagon was correct there is a bit of a voltage sag, the combined battery voltage goes from 8.0v to 6.7v. That's a 1.3v difference, I'm not sure if that's stressing the batteries or if that's normal under load.

Edit: I just tested with two 18650s and the current from them is also 1.3A. With the charged 14250 batteries they are also providing the same current to the laser

Edit 2: I just tested the voltage with the two 18650s, they're only charged to a combined voltage of 7.1v and under the load of the laser it drops to 6.5v.

 

[RedCowboy]

From a RC hobby site.

Base voltage for a cell is 3.7v. Those that obtain the most cycles from their batteries do not go much below 3.4v-3.5v per cell and never use more than 80% of the milliamp capacity in a cycle. The cheaper the battery it seems the more prone to cell damage they are.

If your duty cycle is short and you don't care about the battery, but they seem a bit small.

Float voltage is around 4.17, so if you charge to 4.2 and drop to 3.35 under load I think you are stressing the heck out of them.

You will know if the smoke gets out LOL :na:

 

[Benm]

Hehe, there could be smoke fire or sparks, or they just stop taking a charge after a couple of runs under 1.2 amp discharge conditions, you never really know with these things.

I guess these cells have no protection circuit in them, so over-discharge is a real risk which usually does not result in fireworks, but can ruin lithium batteries to the point where they make paperweights (and very poor ones at that with these tiny things ).

 

[ElectricPlasma]

Lol I've had my fair share in battery explosions, if anyone remembers a thread long while ago that I made where I had a couple magnets short out an 18650 behind my back making it vent itself and fill the whole room up with damn battery gas. The batteries don't even get hot from the current draw I've been testing so I'm not concerned with anything like that happening with these little guys. I spent a dollar on each battery so I wouldn't mind playing around with them until they're dead

 

[HydroSean]

How about speed? Speed is distance per unit time. Power is energy per unit time. This doesn't mean power and energy are the same, and it doesn't mean speed and distance are the same. You're still trying to say they're the same, and they're not. Saying "500mW of energy" makes as much sense as saying "a distance of mach 1.2" or "a speed of 4 meters". I think the fact we're even HAVING this discussion is embarrassing.

You still stand by "power is energy but energy isn't power"? This is categorically ignorant and logically fallacious. I could reference definitions, but I think you'd just double down about how the dictionary is wrong or some ********.

My analogy wasn't with units like distance such as meters, it was of a relationship from speed or rather instantaneous velocity.

 

[Light superglue]

Hi ElectricPlasma,

Why do you think these batteries will not work with NUBM44?

One of my first builds with NUBM44 + SXD driver was just putting them into this micro toy:

https://www.amazon.es/Bosch-Atornillador-acumulador-juguete-pillas/dp/B0009U7LHG

Of course I had to cut 510 threaded heatsink a little to fit in and resolded Fwd/Rew switch to serve as safety switch. Also discarded all original wiring.
Then I replaced two AAA batteries by two 10440 Li-ion (they are even thinner than yours) and was even myself surprised to the output of 5+W despite of crappy toy trigger mechanism (only one steel wire touching steel plate).


Oh, Benm,
And this is the thing I burn ammonium dichromate cystals with.

Focused it puts white paper in flames, ignites magnesium turning - what else do you need from 44. I could even fit 4x cylindricals in (6x would need too long separation) but this host was not worth it.

I have also checked that with 3 Li cells (11V) only 2.5A or less current to SXD driver is needed in order that it feeds 4.5A to NUBM44 for output of 7W.

 

[Benm]

Putting several in serieus using a buck regulator obviously reduces the battery current required, if you put 6 in series it'd be half that (if the driver takes that input voltage at similar efficiency).

As for how much current you can draw: If it's not specified it's anyones guess. Normally something like 1 or 2 C is not a problem, though capacity may suffer a bit (you'd get 20 or 25 minutes at 2C rather than the expected 30).

That is assuming the capacity rating is for discharge with 1C to begin with, it could be at lower current for real world applications such as laptop batteries that generally last several hours under typical use.

Discharging them over 2C would generally unwise if the cells are not specified to handle it.

Batteries intended for high current use (for things like power tools, drones etc) usually come with a specified maximum discharge rating, and capacity derating curve though.