Battery amps and brand

[jpv434]

Hi guys. My name is Jacob. Nice to meet you. I have a question regarding battery amps. I'll get straight to it. I have a tested 3.8w (3800mw) 450nm gatling laser pointer, the short one that takes 2x16340 or 2x18350. What would be the correct and the best amount of amps that this laser would need? I am looking at either shockli 1000mah 10a or vappower 1200mah 10a. Thanks guys.

 

[Unown (WILD)]

10a discharge is more than enough

 

[jpv434]

Thank you

 

[Unown (WILD)]

Oh also welcome Jacob!

 

[LEDbeam]

How is the "continuous amps" known if it is not listed on the battery? Here's what I have:

Sofirn 14500 (which came in a Sofirn flashlight).
Voltage: 3.7 volts
Mah: 900

Nothing about continuous amps.
I'm considering a purchase of a laser that takes a 14500 battery and is said to require 3 continuous amps. Would this one do it?

 

[Gryphon]

For high drain applications stay away from off brands like Sofirn, I'm sure they will be fine in pointers and low power flashlights but if you need power go with a name brand cell like Molicel, Efest or Vapcell to name a few. Check out these tests results I found.

By draining the batteries at know currents and measuring the voltage drop you can determine the cell's internal resistance. The lower the better as you will get less voltage drop, better capacity in a high drain application and less wasted energy being used to heat the battery. At the bottom of the table you'll notice the Sofirn has 0.68ohms while the Efest an Vapcell only clock in 0.09ohms and 0.07ohms respectively

Next, check out the drain tests. As the drain current is increased the measured capacity of the Sofirn drops dramatically (losses from high internal resistance) while the Efest and Vapcell graphs all terminate in mostly the same spot at the bottom of the graph.

All data courtesy of Budget light forum (I didn't make these graphs, just found them on the web)

 

[LEDbeam]

Those graphs look very informative, but I'm unfortunately not familiar with all the technical terms. I don't see where it shows the Sofirn's continuous amp output. Is that there? If it's not at least 3, I'd be curious as to how close it comes to it.

 

[Gryphon]

Sofirn most likely wont list that, they aren't a high drain cell so it wouldn't be necessary to have it stated. Based off of the discharge curves I wouldn't pull more than 0.5-0.75A continuously from that cell, any more than that and you'll see excessive voltage sag and large hit to capacity (runtime).

 

[LEDbeam]

Sofirn most likely wont list that, they aren't a high drain cell so it wouldn't be necessary to have it stated. Based off of the discharge curves I wouldn't pull more than 0.5-0.75A continuously from that cell, any more than that and you'll see excessive voltage sag and large hit to capacity (runtime).

I guess I'd need to get something else then. I never see them at local stores, so it would have to be online, plus shipping.

I just checked https://liionwholesale.com/
The battery was $4.24, but the shipping was $4.69. Good grief!

 

[Enchilada]

You can find the most common cells here. https://lygte-info.dk/info/indexBatteriesAndChargers UK.html
Its a Danish site but all test for the last decade are in English.
You choose the battery segment on top, and then you can go to a given review of that cell or use the comparator to stack battery vs battery in a graph with the corresponding load you are interested in.
it's the native picture-source for test reports posted at #6, the sysop on Lygte-info.dk (Henrik) is also a member on Budget light forum & EEVblog.

 

[LEDbeam]

You can find the most common cells here. https://lygte-info.dk/info/indexBatteriesAndChargers UK.html
Its a Danish site but all test for the last decade are in English.
You choose the battery segment on top, and then you can go to a given review of that cell or use the comparator to stack battery vs battery in a graph with the corresponding load you are interested in.
it's the native picture-source for test reports posted at #6, the sysop on Lygte-info.dk (Henrik) is also a member on Budget light forum & EEVblog.

I ended up getting a couple 14500 cells from Liionwholesale. They arrived on Monday.

 

[paul1598419]

Welcome to the LPF. Enjoy your say and stay safe.