What happens to a battery when...

[Gitum]

So lets consider two of the most popular batteries the LG HE2 and the Samsung 25R. Both batteries have a 20 amp maximum continuous discharge rating and are 4.2v batteries when fully charged. How are people building 0.1ohm coils?

4.2v (full charge) divided by 0.1 ohm resistance is trying to draw 42 amps from a battery that can only discharge 20 amps.. So what is happening to the battery at this point and how many watts are actually being applied since the battery obviously can't draw 42 amps.

+=?

 

[T4T3Z0R]

well two of those batteries in series would allow 20 amps from each if im not mistaken. that gets it closer

 

[ReigntheGamer]

Some people build to the pulse rating. Is it safe? Not willing to risk my face on it.

 

[Gitum]

well two of those batteries in series would allow 20 amps from each if im not mistaken. that gets it closer

No I mean running one of them in a mech. It doesn't matter which one. People are building these coils and firing them on a mech not in a series.

 

[Gitum]

Some people build to the pulse rating. Is it safe? Not willing to risk my face on it.

But how exactly does pulse rating even apply to vaping when we are obviously using them on a continuous discharge.

 

[ReigntheGamer]

But how exactly does pulse rating even apply to vaping when we are obviously using them on a continuous discharge.

They figure is they fire it for less than the length of the pulse it is "safe". I just don't buy into that theory, though many swear by it. I would rather err on the side of caution.

 

[Gitum]

They figure is they fire it for less than the length of the pulse it is "safe". I just don't buy into that theory, though many swear by it. I would rather err on the side of caution.

Okay thanks for that. Even considering this, 42 amps will be (attempted to be) drawn from the battery and even the HE2 only has a pulse rating of 35A which means you are exceeding that the second you hit the fire switch. So what happens at this point?

 

[ReigntheGamer]

Okay thanks for that. Even considering this, 42 amps will be (attempted to be) drawn from the battery and even the HE2 only has a pulse rating of 35A which means you are exceeding that the second you hit the fire switch. So what happens at this point?

The battery heats up and starts heading towards venting, and this is where you get people holding their mods with towels just to vape them. And eventually throwing the battery across the room before it vents. Just o get a bigger cloud.

 

[T4T3Z0R]

MNKE 26650 IMR have a 60 amp pulse rating. they may just not be using the "most popular" batteries http://www.avidvaper.com/products/MNKE-IMR26650--3.7v-High-Drain-Li%2dMN-Battery.html

 

[invisiblehand13]

Okay thanks for that. Even considering this, 42 amps will be (attempted to be) drawn from the battery and even the HE2 only has a pulse rating of 35A which means you are exceeding that the second you hit the fire switch. So what happens at this point?

Ugh...people WILL NOT agree with me but pulse ratings are generally a "moderate" limit, meaning that the more reputable companies will not release a battery that vents at something close to their pulse rating...in other words (and this is JUST ME) I have pushed these batteries to their "limits" and I have NOT had one vent until I built done to .04 ohms on it (yes, in a mech mod) now, bear in mind I did this to test it's limits to see what happened and how far I could push it but I rocked a .07 build the entire battery lifespan on a LG HE2 without ANY venting...yes, this is NOT recommended but it can be done and especially with how far IMR batteries have come venting is much less severe than it was with ICR batteries and the lifespan of this battery at that low of a resistance is SEVERELY reduced but it pushes it and also keep in mind that in EVERY battery batch no matter the manufacturer there can be a bad battery so gentle testing before building something like my builds is STRONGLY recommended so just bear all of what I said in mind and happy vaping!!!!!!!!!!!

 

[jwbnyc]

The battery heats up and starts heading towards venting, and this is where you get people holding their mods with towels just to vape them. And eventually throwing the battery across the room before it vents. Just o get a bigger cloud.

Classic video that.

 

[invisiblehand13]

Classic video that.

You know, people thought I was CRAZY the way I tested my batteries but you should SEE what teenagers are willing to risk in their builds...IMO compared to them I am MORE than safe lol

 

[dgm76513]

So yeah, basically what happens is, the battery is pushed so far its internal resistance becomes a factor. Resistance in a circuit generates heat.

So heat builds up inside the battery, which can lead to thermal runaway, which is a cascading effect until the point of combustion.

When people talk about batteries exploding, well, they're probably referring to the guy in Florida who stacked two batteries in an unvented mod, where something happened that caused one or both of the batteries to vent, and build up a ton of pressure in there and it failed in an unfortunate place which led to him being disfigured and/or partially or fully blind. A quick google search would probably render a result or two for that particular instance.

It really isn't something to play around with if you don't know what you're doing, but IMHO the dangers are a bit overplayed. Better safe than sorry I suppose.

ETA: I'm not trying to downplay the safety issue here. I am stating my OPINION that it seems to be a tad over-dramatized.

 

[Gitum]

So yeah, basically what happens is, the battery is pushed so far its internal resistance becomes a factor. Resistance in a circuit generates heat.

So heat builds up inside the battery, which can lead to thermal runaway, which is a cascading effect until the point of combustion.

When people talk about batteries exploding, well, they're probably referring to the guy in Florida who stacked two batteries in an unvented mod, where something happened that caused one or both of the batteries to vent, and build up a ton of pressure in there and it failed in an unfortunate place which led to him being disfigured and/or partially or fully blind. A quick google search would probably render a result or two for that particular instance.

It really isn't something to play around with if you don't know what you're doing, but IMHO the dangers are a bit overplayed. Better safe than sorry I suppose.

ETA: I'm not trying to downplay the safety issue here. I am stating my OPINION that it seems to be a tad over-dramatized.

Thanks a lot for this. So in essence, is this a somewhat fair way of putting it:
Continuous discharge limit is the maximum amperage you can (relatively) safely draw from the battery consistently.
Maximum discharge (pulse rating) is the absolute highest the battery should ever be pushed and is generally recognized as (relatively) unstable.

Feel free to alter or correct my definitions to make them more accurate or so that I can get a complete understanding.

Ultimately, this is all about education for me as I really am not a super low sub ohm kind of vaper, but I have friends who are, and some of them, I feel may be less educated than they need to be. So I am taking it upon myself to understand this information so I can pass it on to friends and other vapers.

 

[dgm76513]

Thanks a lot for this. So in essence, is this a somewhat fair way of putting it:
Continuous discharge limit is the maximum amperage you can (relatively) safely draw from the battery consistently.
Maximum discharge (pulse rating) is the absolute highest the battery should ever be pushed and is generally recognized as (relatively) unstable.

Feel free to alter or correct my definitions to make them more accurate or so that I can get a complete understanding.

Ultimately, this is all about education for me as I really am not a super low sub ohm kind of vaper, but I have friends who are, and some of them, I feel may be less educated than they need to be. So I am taking it upon myself to understand this information so I can pass it on to friends and other vapers.

That would be the majority consensus around here, and that's a good thing. Continuous discharge is what the battery is designed to handle continuously.

Now, this is a smidge dated, but still very relevant. Pass this along to your friends, if anything. It's badditude's blog about battery safety. He goes in depth about it all, and to be honest, should probably have been the first reply to this thread. - Badditude's blog post regarding battery safety (my own wording on that link)

Have fun and stay safe!

 

[invisiblehand13]

Thanks a lot for this. So in essence, is this a somewhat fair way of putting it:
Continuous discharge limit is the maximum amperage you can (relatively) safely draw from the battery consistently.
Maximum discharge (pulse rating) is the absolute highest the battery should ever be pushed and is generally recognized as (relatively) unstable.

Feel free to alter or correct my definitions to make them more accurate or so that I can get a complete understanding.

Ultimately, this is all about education for me as I really am not a super low sub ohm kind of vaper, but I have friends who are, and some of them, I feel may be less educated than they need to be. So I am taking it upon myself to understand this information so I can pass it on to friends and other vapers.

To start out with EXACTLY what you are saying is smart and "safe" although theoretically there may be a bad battery in any batch of batteries that somehow get through a QC but it is rare, I have around seventy batteries and have only encountered one "bad" battery but I still check all of them to be safe, now just because you are starting out and this is what you SHOULD stick to if you ever get into it with a sub ohmer their views on "safe" limits of batteries are definitely different than what the general consensus is on this forum

 

[Bunnykiller]

well two of those batteries in series would allow 20 amps from each if im not mistaken. that gets it closer

batteries in parallel increase amp capacity, when in series, the amp capacity remains the same but voltage increases by a multiplier of the number of batteries

example: 3 @ 4.2V/20A = 4.2V/60A in parallel... in series, 3@ 4.2/20A = 12.6V/20A