If a lithium ion battery exploded in a flashlight would it blow the light apart?

I did research on 21700s, and I like these the most:

https://liionwholesale.com/collections/batteries/products/molicel-npe-inr-21700-p42a-45a-4200mah-flat-top-21700-battery-authorized-distributor

They're very nice, and fairly cheap, but the wrappers on the cells break easily so you have to be careful not to damage the wrappers.

Good to know
How can you tell if a flashlight is tested and they are not just claiming its certified?

I’m all about capacity so i would want some 5000mAh cells.

You have to ask them for the CE certs or whatever it is you need.

I’ve never seen a certification document for a flashlight. I sold some 8 year old Convoys, i wonder if they had been tested/certified.
How did you figure out that Astrolux/Mateminco refuse to test?

I was a dealer for them and asked for the certs of their new models. Ben, who handles all customer service, said they no longer carry out any testing.

This is slightly concerning that they simply don’t care anymore to make sure their products are safe. Banggood is really their only buyer for the Astrolux brand, so there’s no need in their eyes. If they had a large number of dealers worldwide it would be different.

Every single Convoy model has the CE testing done. They do things properly :slight_smile:

Make sure your light doesn't require high drain cells then.

Impressive honesty :smiley:
Ridiculous business decision :person_facepalming:

Nice! I am curious what is tested, are there any publicly available certificates?

This cell puts out 9.8A.
https://liionwholesale.com/collections/batteries/products/samsung-50e-21700?variant=12667804450910
So 3.6V x 9.8A means 35W. This is good enough for the lights that i’m looking at. As the Convoy M21B i am looking at puts put 1500 lumen i don’t expect any problems. If it takes over 35W to do that then there is a bigger problem at hand.

That said you have inspired me to look up its wattage vs output graph :slight_smile:

That’s not how you choose a battery though. You need to understand that most drivers rely on a battery’s voltage for outputting the highest possible lumens. When you apply 9.8A on the Samsung 50E the voltage will sag on load thus reducing the lumens.

In my opinion, if a torch requires up to 10A I’ll recommend a 15A+ battery. For my Osram 5A builds I’ll bundle a 10A battery, for 10A I’ll bundle a 20A etc. You’ll get longer runtime off a battery if it’s not pushed to its max rating

It seems its run at 6A and is likely a linear driver as its likely a 3V chip
So no problems :slight_smile:
https://www.mouser.ca/new/luminus-devices/luminus-sst-40-w-white-leds/

Since i don’t know much about Luminous LED chips and didn’t think look at the one i was considering i appreciate the unintentional nudge :slight_smile:

A battery’s capacity rating is measured at 0.2C (0.2 X capacity) discharge current. You’ll get less capacity the higher amp load you run the battery at

A Molicel P42A and Samsung 40T may achieve longer runtime than a 50E

Fair enough, i just replied to RC that it needs 6A out so 9.8A should be reasonable.

Nevermind, I missed that it’s only for the Convoy M21B

Interesting.
I hope you don’t mind if i ask you about that in the future if i do end up buying that light.

Which lights do you recommend those cells for?

I meant if the 50E is driven hard, but that doesn’t really happen in a flashlight I think, it only delivers what it’s capable of. Someone else might know a bit more about that.

Looks like the 50E would still provide higher capacity anyway, so the above does apply in this case.

At 10A the 50E still gets 4,750mAh and the Molicel 3,900mAh ish. At 20A+ is where you’d see the Molicel shine.

Best place to compare models cells is here

Which Chinese battery brands do you consider high quality?

A pressure buildup inside of a flashlight is entirely different than a battery explosion. Unless I’m missing something I don’t think we have evidence of batteries exploding in flashlights. Yes there is evidence of flashlights “exploding” from internal pressure. Mostly out of the ends not the barrel itself. Always point your flashlight down range. Just say no to 123s.

Bort… try these Tesla 21700’s from Tech-Direct

chops728 posted about these a while back. I got several & they are great cells.

$11.99 for 3 of them.
No tax & FREE shipping.

You will not be sorry. :white_check_mark:

You are in the USA aren’t you??