Lithium Ion Batteries for lights

[cool_hardware52]

I still have some more testing to do, I can't tell if the voltage is dropping out, or if the charging circuit is limiting the charge because it has more batteries then it is expecting to have. I'm getting about 1/3 the time that I expect, and i have 2.5 times as many batteries as the circuit is expecting.

Tell me what cells your using, how many, the configuration, i.e. series or parallel or both, the nominal voltage of the pack, what your using to control charge, what charger etc and I'll see if I can help.


Tobin

 

[midwest_matt]

Explode in saltwater? I'm no chemist but that doesn't sound accurate at all. L-Ion batteries are completely sealed like any other battery are they not? Submerging it in any liquid with conductive materials in the solution would cause the battery to short. Putting a sealed battery in a high state of discharge like that is definately not healthy for the battery, but it's no grenade.

Someone correct me if I'm wrong.

 

[cool_hardware52]

Explode in saltwater? I'm no chemist but that doesn't sound accurate at all. L-Ion batteries are completely sealed like any other battery are they not? Submerging it in any liquid with conductive materials in the solution would cause the battery to short. Putting a sealed battery in a high state of discharge like that is definately not healthy for the battery, but it's no grenade.

Someone correct me if I'm wrong.

Matt,


Lithium batteries, and Lith-Ion and some others, can explode if shorted. Best way to have excitement with Lithium is to overcharge at a high rate, but over discharge can also be entertaining.

The risks of a "saltwater" short for a lowvoltage pack is not too great however.


The true benefit of Lith-Ion batts is no metallic lithium. Lithium primary batteries with Lithium metal could be dangerous in wet environs, Lithium metal + H20 = Kaboom!


Regards,


Tobin

 

[midwest_matt]

Matt,


Lithium batteries, and Lith-Ion and some others, can explode if shorted. Best way to have excitement with Lithium is to overcharge at a high rate, but over discharge can also be entertaining.

The risks of a "saltwater" short for a lowvoltage pack is not too great however.


The true benefit of Lith-Ion batts is no metallic lithium. Lithium primary batteries with Lithium metal could be dangerous in wet environs, Lithium metal + H20 = Kaboom!


Regards,


Tobin

Thanks for the info

I guess we should define explosion. Are we talking about the battery merely splitting, something like an m80 or bigger?

 

[cool_hardware52]

Thanks for the info

I guess we should define explosion. Are we talking about the battery merely splitting, something like an m80 or bigger?

Matt, One mans "lady finger" might equal anothers M80

What I can say is this: One of the battery pack builders that I have used in the past ( I've build High end Bike Lights for years) uses a floor safe to test his new designs. The safe is not installed in the floor, but it is .25" thick welded mild steel. He puts it out in the parking lot when testing.


He's needed to buy more than one.....................


Regards,



Tobin

 

[midwest_matt]

Hmm I guess with a lithium battery once it's split and the lithium is exposed to the air the reaction is catastrophic.

What about lithium ion batteries?

 

[cool_hardware52]

Hmm I guess with a lithium battery once it's split and the lithium is exposed to the air the reaction is catastrophic.

What about lithium ion batteries?

Lithium - Ion = no metallic lithium, hence no reaction.

Lithium Ion batteries due represent very high energy density however and misuse can be entertaining.



Tobin

 

[lairdb]

Lithium - Ion = no metallic lithium, hence no reaction.

Lithium Ion batteries due represent very high energy density however and misuse can be entertaining.

I suppose that depends on your definitions of "no reaction", "misuse", and "explode".

Valence Technology (a maker of Lithium-ion phosphate type (as opposed to the more common Lithium-ion oxide type) batteries) put out a fairly entertaining video (links at the bottom of the above-linked page; beware of really bad background music) comparing the results of three fairly standard safety tests with a competitor's 4v cell vs. theirs.

As they put it, "...an event occurs...". (The third segment, showing the JBSC nail penetration test, beginning about 1minute 20seconds in is the most fun, um, "event".)

 

[cool_hardware52]

I suppose that depends on your definitions of "no reaction", "misuse", and "explode".

Valence Technology (a maker of Lithium-ion phosphate type (as opposed to the more common Lithium-ion oxide type) batteries) put out a fairly entertaining video (links at the bottom of the above-linked page; beware of really bad background music) comparing the results of three fairly standard safety tests with a competitor's 4v cell vs. theirs.

As they put it, "...an event occurs...". (The third segment, showing the JBSC nail penetration test, beginning about 1minute 20seconds in is the most fun, um, "event".)

My response concerning reaction was with respect to Lithium and seawater.

Crushing or driving a nail through will result in a short circuit, something I cautioned about.

I did not intend to imply that all Lithium - Ion batteries were inherently safe becasue of the lack of metallic lithium.


Regards,



Tobin George

 

[Burner]

I don't think a flood would discharge current as fast as a direct short with a nail.
I'm using this battery:
ICR-18650.H
3 sets of 5 wrapped around a dowel.
The batteries are from laptops, I am using the circuit in the laptop battery, and charging it with a laptop.
I'll be on vacation for a while so I won't work on it for another couple weeks.