Are Li-Ion Batteries That Dangerous?

[mrmakochan]

Hello, I'm a noob on this forum and recently stared reading about Li-Ion batteries.

I have a 6P with a CREE drop-in and wanted to buy the AW RCR123A batteries, but I hesitate since I've read some of the dangers involved.

http://www.candlepowerforums.com/vb/showthread.php?t=183467
http://candlepowerforums.com/vb/showthread.php?t=161536

But then I realized that I've been using Li-Ion batteries for a number of years on cellphones, cameras, laptops without any issues. I've never experienced any venting, burning, melting, etc. Am I just lucky or is there something about RCR123A that make them more dangerous? Maybe its the high discharge rate?

I sometimes leave my laptop plugged into the outlet for days. Is that bad? Or maybe there's a cut-off circuitry so I don't need to worry about.

I also read about people measuring the voltage across batteries to make sure that they are not over-charged or over-discharged. Should I buy a multimeter to start doing this with all my Li-Ion batteries?

Thanks for the help. This is a great forum! :thumbsup:

 

[SilverFox]

Hello Mrmakochan,

Welcome to CPF, it appears that you don't post very often...

Li-Ion batteries are dangerous because of their high energy density.

Your cell phone, camera, and laptop are designed around the use if their specific batteries and have design limits and circuit protection built into them. Most flashlights do not offer this.

If you took a bunch of cell phone batteries and hooked them up to power, and be charged by, your laptop, you may run into some of the same dangers.

If you have a light that is designed to use R-CR123 cells, and have a charger that is designed to charge R-CR123 cells, and use cells that have an integral protection circuit built into them, you should not have problems using them.

Tom

 

[LiteShow]

But then I realized that I've been using Li-Ion batteries for a number of years on cellphones, cameras, laptops without any issues. I've never experienced any venting, burning, melting, etc.

Here's my take on this issue:

Just as SilverFox mentioned, Cellphones, cameras and laptops are generally safer because of the way the batteries are specifically designed for the electronics and behavior of the appliance, and backed up by the built-in protection circuits. Also, the batteries of these consumer devices are NOT usually contained in an air-tight container.

In contrast, Li-ion use in flashlights is more risky because
(1) the batteries may not be designed for usage with the current draw and flashlight type usage and may be more proned to failure as a result
(2) should any venting of gases occur because of malfunction, these gases can't easily escape. Pressure builds up in the air-tight container and the result is - just like a pipe bomb.

That's why I only use LiFEPO4 safe chemistry type Li-ions in my CR123A flashlight (Fenix P1D Q5). The chemical properties ensure that there are no gases released under deep charge or discharge, unlike regular Li-ions. They are available in CR123A, 18650 and maybe some other formats.

 

[LEDninja]

AW sells protected/unprotected & LiFePo4 RCR123A cells. Buy the protected or LiFePo4 ones.
Also make sure your smart charger will shut off at the right voltage. The max voltage of Li-on and LiFePo4 are different and require different chargers.

Here is a review of the dangers of lithium batteries and how to handle them safely.
http://flashlightreviews.com/features/123burst.htm

Most of the cases I've read of exploding lithium batteries are a result of user carelessness or abuse and use of cheap batteries of unknown origin. Also most of the exploding batteries are primary rather than rechargeable though this could be because there are more primary cells out there.

Your 2nd link has guideline on the safe operation of Li-on batteries.
Follow them and you should be safe.
do not charge above 4.200V
-If you have a smart charger and protected batteries you have double protection.
-"I closely monitor and always pull cells as soon as the light goes green."
do not discharge below ~3.5V rested open-circuit (3.5V is basically dead on a li-ion cell)
-AW protected batteries have low voltage protection.
-Some chargers also have low voltage protection. They assume cells with a voltage below 2V are damaged and refuse to charge. Check charger specs.
-"Ideally speaking, even though you are using protected cells, You should mentally keep track of how much runtime you have used on the light, and watch for dimming. When the light starts to seem noticeably dimmer you should plan on recharging as soon as possible." (Most of the exploding battery threads I read, the operator kept running the light after this point or was doing a runtime test or otherwise running the light unmonitored. Or forgot to turn the light off & take the batteries out after the torch stopped working)
-"The nice thing about Li-Ion is that it does not develop memory issues, just put em on the charger when ever you want to top them off."
do not discharge faster than 2C (some cells as low as 1C), which means in less than 30 minutes. Some cells out there are rated for no faster than a 1 hour discharge rate.
-A drop in with a single Cree should be within 2C of most Li-ons. Check the drop in max draw against battery rating.
-Some LiFePO4 have very low discharge rates. For example the Fenix P2D turbo mode (~700mA) exceeds the max discharge rate of Tenergy LiFePO4 cells (~550mA).
do not charge faster than 1C (in 1 hour).
-If you use dedicated RCR123A chargers you should have no problem. If you use a hobby charger you need to set the current correctly.

Working through this post has been a good refresher course for me as I got my 1st dedicated 14500 torch yesterday (won't run on AA).