Sub-Ohm Newbie Question

[Mooch]

Thrasher" data-source="post: 15829467" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch">

Less then 1 second..............

That should never ever ever have anything to do with a conversation around vaping.

The Samsung inr is used in cordless tool powerpacks and this is a trigger buffer so the cell is not damaged in the time it takes for the power pack overload switch to activate in a situation like the tool is jammed or overheating.

That is just for an unavoidable spike. There is no way it can continually sustain that type of abuse.

Verrry good points! I don't want to even think about the temperature that cell would reach, even if the draws were taken many seconds apart.

LOL...and we're back to pulse ratings again Thrasher!

 

[yuseffuhler]

I have a question for ya Speedy. I was looking at charts earlier today for the max wattage/voltage certain resistance atomizers can take before they "burn out". For my istick with the nautilus mini 1.8 ohm atomizer it was saying my max voltage is 3.9V (AKA 8.45 Watts). This means id be pulling 2.1 amps from the battery. The battery has a CDR of 4.87. Seems like theres a lot of wiggle room for the battery there. So should i go by the amount of Amps the battery can safely take to determine where i can safely maximize how much im vaping? Or should i be looking at how much the atomizer can handle according to these charts?

Please keep in mind that those charts are based on older tanks and atomizers. almost all tanks have much better airflow than the previous tanks we had, which means you can push more wattage through a coil (more airflpw means more cooling the coil so it doesn't cook the juice)

 

[Thrasher]

Probably should have read the whole post.....

Panic meter when off when I saw 100 amp lol

 

[Mden89]

This is a very tricky question and I will try to make it simple.

The 2.1 would be at a set voltage of 3.9.
When the battery is full this is fine.

As the battery gets weaker the mod still wants 3.9 but the battery is 3.7 now so the chip actually pulls more amperage from the battery and turns it into voltage .

Depending on how efficient ( or not) the chip is it could end up asking for more then that battery can deliver.



The other question- I usually go to 75 -80% of a cells rating, some people say 50%

Thank you very much for the explanation Thrasher. So my new question would be; at what point does the battery life begin to compromise the performance output? In other words... do i want to keep the batteries as close to a full charge as possible at all times to allow them to run at what i set them to? Also, how do you know how much voltage/wattage you are losing at certain battery percentages?

I know im asking a few questions at once but i want to get the most information out of each post so we dont have to go back and forth a million times... I hope you dont mind.

If im trying to run my eleaf stick at 3.8V and it is at 50% battery life, are you saying that will change the amount of amps the battery can handle?

I sincerely thank everyone for their contributions to my education here LOL!

 

[speedy_r6]

I have a question for ya Speedy. I was looking at charts earlier today for the max wattage/voltage certain resistance atomizers can take before they "burn out". For my istick with the nautilus mini 1.8 ohm atomizer it was saying my max voltage is 3.9V (AKA 8.45 Watts). This means id be pulling 2.1 amps from the battery. The battery has a CDR of 4.87. Seems like theres a lot of wiggle room for the battery there. So should i go by the amount of Amps the battery can safely take to determine where i can safely maximize how much im vaping? Or should i be looking at how much the atomizer can handle according to these charts?

Worry about the amp rating of the battery. Most of those charts are outdated, and you can go to a MUCH higher wattage. Theoretically, if you were running that 1.8 ohm setup all day, you could probably get away with that lower performance battery. Here is the problem. You are going to pay nearly as much for that one as a high discharge battery. If you ever want to go lower ohm, you will NEED that high discharge battery. At that point, you have basically made that first purchase of the low end battery pointless.

Long story short, buy the best battery you can. You can never be too safe when it comes to batteries.

 

[justincase]

Don't mind me.
Just passing through to place a bookmark!

 

[speedy_r6]

Thank you very much for the explanation Thrasher. So my new question would be; at what point does the battery life begin to compromise the performance output? In other words... do i want to keep the batteries as close to a full charge as possible at all times to allow them to run at what i set them to? Also, how do you know how much voltage/wattage you are losing at certain battery percentages?

In a regulated mod, the battery getting lower on voltage doesn't have an impact on the performance, so long as the battery can put out enough amps. If you are running at 3.8 volts and your battery is fully charged(4.2 volts), it will draw 4.2 volts from the battery, but at lower amps and then just step the voltage down via the internal circuitry. If you are trying to run 3.8 volts and your battery is at 3.6 volts, it will draw the 3.6 volts at a higher amp draw to be able to step it up to 3.8 volts via the internal circuitry.

I know im asking a few questions at once but i want to get the most information out of each post so we dont have to go back and forth a million times... I hope you dont mind.

Don't feel bad. There is nothing wrong with people trying to learn.

If im trying to run my eleaf stick at 3.8V and it is at 50% battery life, are you saying that will change the amount of amps the battery can handle?

The battery's chemistry can handle a specific amount of amps. The voltage doesn't matter. The battery can only safely supply the certain amount of amps. With a regulated mod, it revolves more around wattage. If you are drawing 40 watts, you are drawing 40 watts. If the battery is at 4.0 volts when you are drawing that 40 watts, the battery is pushing 10 amps. If the battery is at 3.3 volts, you are drawing 12.2 amps.

I sincerely thank everyone for their contributions to my education here LOL!

See the parts in bold and italics.

 

[Thrasher]

First off keep asking, only way to learn.

With a regulated mod just run it till it says they are dead.

No it won't change the amount the mod can handle. That is set in stone.

The amount of amps being pulled from the battery gets higher as the battery dies,

The battery can't stay at 4v forever, but the mod says no I want 4 volts, so the battery can only do one thing, increase amps and the mod turns that into the voltage it needs.

The battery dies a little more, the amps go up a little more.

So your tank is only using 2 amps but the battery is now at 4 to keep it there

The chip inside the mod is doing 2 different things controlling the power pulled from the battery and controlling the power going to the tank

What's happening to the battery doesn't get noticed on the tank side, that will always stay 3.9 v at 2.1 amp

 

[Mden89]

First off keep asking, only way to learn.

With a regulated mod just run it till it says they are dead.

No it won't change the amount the mod can handle. That is set in stone.

The amount of amps being pulled from the battery gets higher as the battery dies,

The battery can't stay at 4v forever, but the mod says no I want 4 volts, so the battery can only do one thing, increase amps and the mod turns that into the voltage it needs.

The battery dies a little more, the amps go up a little more.

So your tank is only using 2 amps but the battery is now at 4 to keep it there

I guess what's getting me a little confused is the differences between amps,watts, and volts. Particularly why/how the battery will run at higher amps when it is no longer at full battery life to be able to put out the same amount of voltage or wattage.

How does more amps translate into more volts when the battery is no longer full enough to provide the volts? Maybe I just need to google the 3 words? Lol

 

[Mden89]

See the parts in bold and italics.

So does this mean that the lower the battery life, the more strain (in amps) that will be applied? Is this why I've heard some people say draining the batteries is not good for them?

 

[speedy_r6]

I guess what's getting me a little confused is the differences between amps,watts, and volts. Particularly why/how the battery will run at higher amps when it is no longer at full battery life to be able to put out the same amount of voltage or wattage.

How does more amps translate into more volts when the battery is no longer full enough to provide the volts? Maybe I just need to google the 3 words? Lol

If you are running at 3.8v on a 1.8ohm coil, you are running at about 8 watts(8.0222 to be exact, but let's just use 8 for easy math). That means your battery has to be supplying 8 watts of power. Watts are volts*amps. If your battery is at 4 volts, that means the battery is running at 2 amps to provide those 8 watts. The internal circuitry in the mod is going to step those 4 volts at 2 amps down to the desired 3.8 volts, but it will be providing 2.111 amps to the atomizer.

Now, as the battery goes down in charge, it still has to provide those 8 watts. If it is down at 3.5 volts, it will be running at 2.285 amps to provide the 8 watts needed. From there, the internal circuitry will step the voltage up to the 3.8 volts you are wanting to run to the atomizer, and the 3.8 volts will be at 2.111 amps.

 

[speedy_r6]

So does this mean that the lower the battery life, the more strain (in amps) that will be applied? Is this why I've heard some people say draining the batteries is not good for them?

Yes. As the battery gets drained in a regulated mod, it is forced to run at a higher amperage to keep up. A quality mod will always cut the battery off before it gets anywhere close to its point of failure.

 

[Mden89]

If you are running at 3.8v on a 1.8ohm coil, you are running at about 8 watts(8.0222 to be exact, but let's just use 8 for easy math). That means your battery has to be supplying 8 watts of power. Watts are volts*amps. If your battery is at 4 volts, that means the battery is running at 2 amps to provide those 8 watts. The internal circuitry in the mod is going to step those 4 volts at 2 amps down to the desired 3.8 volts, but it will be providing 2.111 amps to the atomizer.

Now, as the battery goes down in charge, it still has to provide those 8 watts. If it is down at 3.5 volts, it will be running at 2.285 amps to provide the 8 watts needed. From there, the internal circuitry will step the voltage up to the 3.8 volts you are wanting to run to the atomizer, and the 3.8 volts will be at 2.111 amps.

Excellent I had that "ah hah" moment... Finally lol.

So the lower battery percentage my device has, the more amps it will need to use to achieve the desired volts.

Now that I know this, does it ever raise concern that your battery is potentially getting close to its maximal amp load when it's running on very low battery life?

Say for example I am using the eleaf stick we have been discussing with the 1.8 atty. I think we established it can get up to 5amps max? Either way let's use that just as a number for now. If I'm firing up at 3.8v, that's 8watts like you said. Which is 2 amps for the battery. If the battery is at 25% battery life how do you know how many volts are remaining to calculate the amount of amps that will be stressed on the battery? Does each battery have a max voltage?

 

[Mden89]

Yes. As the battery gets drained in a regulated mod, it is forced to run at a higher amperage to keep up. A quality mod will always cut the battery off before it gets anywhere close to its point of failure.

THANK YOU LOL. This is what I was inevitably getting at here. I didn't want to have to worry about the battery being damaged at low life. As long as I know the damn thing won't get stressed to the point of failure as the battery life drains to nothing I am content with what I know lol.

 

[Martnargh]

Get vtc4s from lightningvapes. Best batteries for vaping hands down.

 

[RandyF]

The XTAR VC2 charger is a very good choice. Charging from drained (3.0V) to full (4.2V) the charger will tell you the mAh (capacity) of your battery, important information as the batteries age. It has a couple other nice features as well, for $20 it is a good investment.

Kidney Puncher is sold out, but RTD has them.

Also, be VERY careful, if not completely avoid, buying batteries, or anything related to batteries, off EBAY. When it comes to batteries or chargers, it is worth spending a few more dollars to buy from a well known supplier.

 

[speedy_r6]

Excellent I had that "ah hah" moment... Finally lol.

So the lower battery percentage my device has, the more amps it will need to use to achieve the desired volts.

Correct

Now that I know this, does it ever raise concern that your battery is potentially getting close to its maximal amp load when it's running on very low battery life?

In a sealed mod, it doesn't, so long as the mod is of decent quality. Now, if it is a mod where you put your own batteries, that is all on me. The mod SHOULD have a low voltage cutoff somewhere around 3 to 3.3 volts. Now, if you are trying to run 70 watts on a battery rated for 20 amps, there becomes a danger after the battery hits about 3.5 volts. This is when it comes down to the person using it knowing the limits of their hardware.

Say for example I am using the eleaf stick we have been discussing with the 1.8 atty. I think we established it can get up to 5amps max? Either way let's use that just as a number for now. If I'm firing up at 3.8v, that's 8watts like you said. Which is 2 amps for the battery. If the battery is at 25% battery life how do you know how many volts are remaining to calculate the amount of amps that will be stressed on the battery? Does each battery have a max voltage?

A drained battery is typically cut off between 3 volts and 3.3 volts(normally closer to 3.3), depending on who makes the mod. A fully charged battery is 4.2 volts. My Innokin MVP 2.0 cuts off at 3.3 volts. My iStick 50w cuts off at the same voltage. The 20w and 30w models of the iStick all cut off at 3.3 volts. At 25% battery left, it means your battery is probably putting out 3.5 or 3.6 volts. Assuming you have the 30w version, if you are running the full 30 watts, you are drawing about 9 amps. At the 8 watts you are using, you are only drawing about 2.3 amps. At 2.3 amps, you should have absolutely nothing to worry about. I imagine they are probably running a battery that is rated for 15 or 20 amps, so it would be safe to run it to the cutoff point.

See bold and italics

 

[ElConquistador]

Your regulated mod takes out all the guessing. Set it and forget it.

 

[Thrasher]

Excellent I had that "ah hah" moment... Finally lol.

So the lower battery percentage my device has, the more amps it will need to use to achieve the desired volts.

Now that I know this, does it ever raise concern that your battery is potentially getting close to its maximal amp load when it's running on very low battery life?

Say for example I am using the eleaf stick we have been discussing with the 1.8 atty. I think we established it can get up to 5amps max? Either way let's use that just as a number for now. If I'm firing up at 3.8v, that's 8watts like you said. Which is 2 amps for the battery. If the battery is at 25% battery life how do you know how many volts are remaining to calculate the amount of amps that will be stressed on the battery? Does each battery have a max voltage?

This is the exact reason we say only use high drain batteries, low drain cells "may" reach their limits

 

[Mden89]

The XTAR VC2 charger is a very good choice. Charging from drained (3.0V) to full (4.2V) the charger will tell you the mAh (capacity) of your battery, important information as the batteries age. It has a couple other nice features as well, for $20 it is a good investment.

Kidney Puncher is sold out, but RTD has them.

Also, be VERY careful, if not completely avoid, buying batteries, or anything related to batteries, off EBAY. When it comes to batteries or chargers, it is worth spending a few more dollars to buy from a well known supplier.

I purchased the NITECORE i2 charger. I read in another post that this was a good charger as well. Will this also tell me the mAh capacity of my battery? Volts?