How hard it is to kill an unprotected cell?

[Skylumen]

Led still lit

 

[lampeDépêche]

Over on the General Flashlight forum there's a thread looking for a light for "Self defense, and uses an 18650"

http://www.candlepowerforums.com/vb/showthread.php?426555-Self-defense-and-uses-a-18650

Seems like we could combine these threads to do a comparison:

How hard it is to kill an unprotected 18650, vs. how hard is it to kill an 18650 that has learned how to protect itself by taking self-defense courses?

"Stay back! I was manufactured in Japan, and I know karate!"

 

[Skylumen]

LED still lit

 

[degarb]

The newish 3500mAH batteries die pretty easy. I had 4 of them in my TMo4vn (which has a constant, blue LED power available light) and have killed 3 of them dead dead dead. These are the first batteries I have ever run across that simply die from overdischarging.... They were NEW too, so I'm not very impressed with them.

Are you sure they weren't protected 3500s. . If the protection trips it will read 0V. A good smart charger will not charge it. So, jump it or buy a Cheap not so smart charger that will pump anything.

Also, Panasonic 3400s are made to go to 2.5V, while other brands are 3V. On a single cell or parallel amc7135 based controller lights it is impossible to go much below 2.9 volts, as the FWV at 300 is 2.7 and the controller dies at just below .2V above FWV.

About the only time one can safely take advantage of the extra runtime is in a buck controller, like the buckpuck, with a 2.5 v cut off and 2plus cells in series. You might get much significant time in a 4s18650, or small significant in a 2s. If your electric socks or work light or bike light dies, even half hour or hour shy of full daily service time, over 300 days a year, it means double cycles, plus, upwards and into, thousands of dollars lost, from a business point of view. . So, 45 minutes of lost runtime, is a big deal. . Even for recreational usage, multiply number of users of your product times how much inconvenience time. .

 

[Thom2022]

This thread went a bit topic wobbly so I'm just gunna chime in with something that may or may not be relevant. Mooch from ECF tests A LOT of batteries hard for vaping purposes. He tests ALL down to 2.5v through numerous cycles therefore I am happy to discharge to 2.5v on any battery as battery safety is that mans job. When a battery over discharges it develops shunts which causes the danger when recharged. Some chargers can recover the battery from very low states. Just google metallic shunts in li ion batteries and you should find some useful info.

 

[aginthelaw]

Get a webcam so you can live stream it

 

[wimmer21]

Just popping in to see if anyone's talking about me.

Carry on

 

[Bdm82]

Just popping in to see if anyone's talking about me.

Carry on

I was, but in a different thread. Though now, I reckon, I am.

 

[eekazum]

if yer real quiet, maybe you can hear energizer bunny pounding inside.

 

[eekazum]

Just popping in to see if anyone's talking about me.

Carry on

Aight everyone! coast is clear!!

 

[lampeDépêche]

I don't mind it when they say, "and speaking of killing batteries, do you remember that time that LampeDépêche toasted a set of 18650s?"

What I mind is when they say, "speaking of dim bulbs, where's LampeDépêche?"

 

[Skylumen]

LED is still glowing

 

[eekazum]

daaang. whats the voltage on the battery?

 

[richbuff]

An era has ended, another whole new era has begun, and...



...



...LED is still glowing

 

[Skylumen]

LED still glowing

 

[vudoo]

Wow....

 

[vadimax]

LED still glowing

Do you have a Geiger counter? Perhaps, it has a nuclear reactor inside

 

[Skylumen]

So it has been 5 months already and the LED is still glowing. At the start of the test the battery was deleted enough that the LED glow dimly. Battery still reads 2.5V today ... for what its worth

 

[richbuff]

As we sail into the mystic, is the led still glowing?

 

[Illum]

I think you should swap out the LED for one with a lower forward voltage.... like a red LED... [Vf: 2.1 or so]