On the KX3 mailing list, somone wrote:
For anyone who would like to know why Lithium batteries can be so dangerous I ran across this interesting video from PBS Nova. If you have not seen it yet take a look. It should be worth you time.
Another guy replied:
None would think lithium batteries were “so dangerous” were it not for what I call internet reporting. No one will much remember a story about a cell phone where the battery got hot and had to be discarded. If it blows up now that’s another story.
I’ve never understood how a cell phone can catch fire in someone’s pocket. Lithium batteries don’t get “hot and blow” up under a light load. And they don’t all of a sudden blow up. Hot pocket? Take it out.
The batteries in the hoverboards caught fire because of poor design. The battery not having the capacity to deliver the current required or the charger being faulty. Why would you keep both feet on the hoverboard if you noticed something wrong. Like getting hot, smells funny, hoverboard slows down or stops.
Lithium batteries are very tough and reliable if used according to specs and charged correctly.
In any case the flat packs seem to cause the most trouble. I see them sort of like a small dog vs. a big dog. Both can have aggressive and hostile tendencies. Small dogs don’t scare me. Big hostile and aggressive dogs do. Lithium batteries are little dogs.
I’m not a battery expert, but from what I’ve read, it seems like they can be dangerous, so handling and charging them with care seems appropriate. What do you think?
Charles says
I guess it all has to do with energy density… the higher the energy density you can pack into a little cell the more dangerous a rapid discharge can be. Just like these Super Caps these days. they can melt a screwdriver if you short it. hey when is the next Technician Ham Radio class at the A2 Hands on museum, I am trying to talk my dad into getting his Tech License.
W4RAX says
There are several lithium chemistries used in batteries. The lithium ion and lithium polymer batteries tend to be more volatile than lithium iron phosphate. NT8B gave an interesting talk on the subject to the Vienna Wireless Society in VA last fall: https://www.youtube.com/watch?v=Fp6YHQWyHco
Thom W8TAM says
I have and use lithium primary cells (18650) in my day to day life. In fact, I have one in my pocket right now. The battery in my EDC flashlight is a 3400mAh protected cell. I use both protected and unprotected cells in my flashlights, to power my CPAP machine when I hike, my QRP radio, and other 12v power needs. I use my flashlight all the time, and charge it only a few times a year.
The potential energy these batteries can hold is what makes them worthy of care when using them. Simple Alkaline or lead acid batteries can’t output the large currents that lithium batteries can. When using them in high amp draw situations (fast charge or discharge), part of the process is monitoring the temperature of the cells.
If you use the batteries for high amp draw/charge, and don’t monitor the temp, that’s when problems can occur. Laptop manufacturers learned that lesson a while back, and Samsung learned it too. You can also run into trouble if you over charge, or discharge a lithium cell too far.
I think a lack of education is the issue here. You can use a AA or D battery as hard as you like with no real danger. Run it until it’s empty and throw it away. Doing the same thing to a lithium cell will have unintended consequences.
Lithium Iron Phosphate (LiFePo4, or LFP) batteries are another story. They aren’t quite as energy dense as Lithium Ion, but similar… They don’t have the same fire potential Lithium Ion does.
I have a LFP battery in my Hardened Power Systems Juicebox. It’s a 40aH battery, with about 80% of the capacity usable. With a 450w inverter, 10amp charger, and 30amp capable solar charger installed in a ammo can, it weighs about 30lbs.
Lithium batteries also present much lower internal resistance to lead acid batteries. This allows even a small charge current to effectively charge a Lithium pack over time. It’s not ideal, but it does work.
I’m cautious about what manufacturers batteries I buy. I’m also cautious about where the batteries are manufactured. There are some crazy labels on batteries out there, that when tested, don’t live up to their labels. I avoid Lithium Ion batteries with the word ‘fire’ in the brand name. Seems like a bad omen. :D