# Shaun's Guide to Battery Safety



## shaunnadan

Shaun’s Guide to Battery Safety

There is an incredible amount of information available for those who intend to vape at sub ohm resistances. However, there seems to be a lot of misconceptions going around about how to sub ohm safely due to some gaps in our knowledge. As a fellow sub ohm vaper I wanted to clarify a few things that seem to be frequently misunderstood about how to vape safely.

This post is geared toward those who already understand the basics of sub ohm vaping.

*Minimum safe resistance*

It seems to be very common for people to seek out batteries specifically for their high current ratings. 

However, for the majority of sub ohm vapers, this high of an amp rating is unnecessary, and can even be misleading. In fact, there is a very narrow window between vaping at 20 amps (A) and vaping at 30A, and unless your coil build happens to fall within this tiny window, 30A batteries aren’t going to be much more useful to you.

Let me illustrate my point. We are all familiar with Ohm’s law: voltage equals current times resistance, or V = I*R. With a little algebra we can find out what resistance we have at a certain voltage and current, R = V/I. Using this equation we can find the minimum resistance we can build to given the current rating of the battery.

For all 18650 and 26650 batteries, the maximum voltage when charged is 4.2 volts (V). Plugging this into the equation along with the max continuous current rating of the battery will give you the absolute minimum resistance you can build to without overstressing your battery.

For a battery rated at 20A continuous, we have R = 4.2V / 20A = 0.21 ohms (Ω).

At 30A, we have R = 4.2V / 30A = 0.14Ω.


*bottom line is there is a point where your build resistance needs to stop before you create a risk on your batteries even though your mod will still fire them.

*Amp ratings – continuous versus pulse*

Many people say that they can build to very low resistances because they go by the battery’s pulse rating rather than the continuous rating. It is rumoured that batteries can handle a much higher current output because of the pulse rating.

this is false.

Continuous amp ratings are the maximum current that the battery can handle discharging over a very long period of time. Pulse ratings, on the other hand, are the maximum amount of current the battery can discharge in a very short period of time.

The problem with pulse ratings is that there is no universally accepted standard for battery companies to test pulse ratings. A pulse is simply defined as a discharge in a brief time window, but there is no way to know exactly how long that pulse lasted in testing. A pulse time can be anywhere from a couple seconds all the way down to a fraction of a second – in theoretical mathematics, the time of a pulse is considered “infinitely” short.

How long do you hold the button down when vaping? Try timing it – I’m willing to bet it’s somewhere between 2 and 10 seconds. Did the battery factory time their pulse testing to accommodate that? Probably not.

Since we have no way of knowing how pulse ratings are determined, it’s safe to assume they don’t apply to vaping. It’s better to stick to the continuous amp rating.

*Batteries in pairs*

There are now many mods available that accommodate two, or more, batteries at once. There is a significant difference in performance capabilities between whether they are connected in series or parallel.

It is important that you always buy the pair of batteries used in the mod together, and always use them together and charge them together. Any difference between them can lead to one battery pumping out more voltage than the other and becoming strained. This is often referred to as “married batteries”

Batteries connected in series will retain the same current but double the voltage. For instance, if you use two 20A batteries, you will still have a max current discharge of 20A, but you will have a max voltage output of 8.4V. This is helpful if your goal is to maximize power, or wattage (W), without decreasing the resistance of your build.

In fact, this will increase your power by a lot. Power is equal to the voltage times the current, or P = V*I. If you use 20A batteries and build to the lowest resistance possible, your power from one battery at max voltage is 4.2V * 20A = 84W. If you stack two of these batteries, however, your power is now 8.4V * 20A = 168W! 

Many people who stack batteries find that they prefer building their coils to a higher resistance because of this.

Batteries wired in parallel will retain the voltage but double the current. So now if you use two 20A batteries, you will retain a voltage of 4.2 but have a max continuous current of 40A. This allows you to lower the resistance of your build.

If you pair two 20A batteries, your minimum resistance is now 4.2V / 40A = 0.11Ω. If you pair two 30A batteries, your minimum resistance becomes 4.2V / 60A = 0.07Ω!

That’s about as low as it gets. If you plan to build to extremely low resistances, I highly recommend buying a box mod that runs batteries in parallel.

*Regulated Mods Internal Safety Mechanism*

A lot of people would say they don’t worry about what they build because their mod will protect them. It will give you an error when you going wrong. I fully agree that this will happen for errors like short-circuits, reversed polarity, and when exceeding the chipsets lowest resistance.

But not all mods are created equally and I have seen me far share of mods DIE a slow and painful dealt because of incorrect batteries and unsafe builds.

My intern is a very dumb person. He got himself an IPV3 li and then instead of buying a pair of decent batteries he went to the china mall and got himself a pair of ultrafire 18650’s because it’s the same thing as his father’s torch and only cost R20.00 each! He then built a Clapton build and pushed his to 100W. After a few min he started to feel his mod vibrate in his hand, smoke started to pour out of the batteries as it leaked and then bang! His mod had melted.

My personal legendary sigelei 150w however had a different story. I had built a super sub ohm coil. 0.12 ohm resistance and was firing it at 150w. Once the battery got to 80% it refused to fire and had the check battery message. So I took the batteries out and placed them into the snowwolf with the same atty and it fired. So I kept vaping for another 5min and then the front panel of the snowwolf started to get very hot especially where the buttons were. There was a feeling of a relay clicking inside the mod each time I fired it and I then decided to stop playing around and packed it all away.

There was something in the chipset of the segelei that refused to fire the mod when the batteries got too low to power that coil but not in the snowwolf.

The most important thing is to check what mod you have, then consider what batteries your using and look at the ohms law chart and see what’s your lowest available resistance. I very often choose to build lower than what is recommended for me and push higher power than I should but I do it with full knowledge of the risks and have only myself to blame if something goes wrong.

Reactions: Like 4 | Winner 1 | Thanks 3 | Informative 6 | Useful 1


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## Rossouw

I see your name pop up everywhere and thought you would be the perfect person to ask this. When I check the voltage of my batteries on my RX200 the readings between the batteries always differ (at the moment it reads 3.69v, 3.78 and 3.95) is this a problem or safety hazard? Im using Tesiyi's. 
Also I am picking up a Nitecore I4 charger tomorrow, will it help in this regard?


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## Christos

Rossouw said:


> I see your name pop up everywhere and thought you would be the perfect person to ask this. When I check the voltage of my batteries on my RX200 the readings between the batteries always differ (at the moment it reads 3.69v, 3.78 and 3.95) is this a problem or safety hazard? Im using Tesiyi's.
> Also I am picking up a Nitecore I4 charger tomorrow, will it help in this regard?


The voltage difference is too high for my liking. 

Yes the nitecore should charge them all to 4.2v and then monitor their discharge. 

Those values indicate that 2 of the batteries are doing more work or rather have a greater load than 1 of them. 

Were the batteries purchased together? 

The problem comes in when you are running your mod at 10% battery life.
Let's say the one battery is at 2.7 volts and the one goes below 2.2v. The 2.2v might vent because it has dropped below it's threshold and thermal runaway is very real and dangerous.

Firstly, charge them fully on a charger. 
Secondly, rotate their position regularly. 
Thirdly, monitor them closely checking voltage regularly. 

I use a dna 200 rolo and although the batteries are charged and monitored independence I never see them vary more than 0.01v. Eg one battery will be 4.11v the other 2 will be 4.10v.

Lastly, make sure the batteries are the same brand and roughly the same age. I'm sure you probably used new batteries.

Reactions: Thanks 1 | Informative 2


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## Rossouw

Christos said:


> The voltage difference is too high for my liking.
> 
> Yes the nitecore should charge them all to 4.2v and then monitor their discharge.
> 
> Those values indicate that 2 of the batteries are doing more work or rather have a greater load than 1 of them.
> 
> Were the batteries purchased together?
> 
> The problem comes in when you are running your mod at 10% battery life.
> Let's say the one battery is at 2.7 volts and the one goes below 2.2v. The 2.2v might vent because it has dropped below it's threshold and thermal runaway is very real and dangerous.
> 
> Firstly, charge them fully on a charger.
> Secondly, rotate their position regularly.
> Thirdly, monitor them closely checking voltage regularly.
> 
> I use a dna 200 rolo and although the batteries are charged and monitored independence I never see them vary more than 0.01v. Eg one battery will be 4.11v the other 2 will be 4.10v.
> 
> Lastly, make sure the batteries are the same brand and roughly the same age. I'm sure you probably used new batteries.


Yes I bought all three together. I usually charge the batteries when they are just below 50%. I was beginning to worry about that difference and finally decided to get an external charger. A few weeks ago I noticed I never get a full charge anymore, always one battery sitting at 4.21 and the other two lower. Thank you! Appreciate the help. 

If the batteries still show different discharge rates what should I do? Can this be a problem with the mod or the batteries?


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## shaunnadan

Christos said:


> The voltage difference is too high for my liking.
> 
> Yes the nitecore should charge them all to 4.2v and then monitor their discharge.
> 
> Those values indicate that 2 of the batteries are doing more work or rather have a greater load than 1 of them.
> 
> Were the batteries purchased together?
> 
> The problem comes in when you are running your mod at 10% battery life.
> Let's say the one battery is at 2.7 volts and the one goes below 2.2v. The 2.2v might vent because it has dropped below it's threshold and thermal runaway is very real and dangerous.
> 
> Firstly, charge them fully on a charger.
> Secondly, rotate their position regularly.
> Thirdly, monitor them closely checking voltage regularly.
> 
> I use a dna 200 rolo and although the batteries are charged and monitored independence I never see them vary more than 0.01v. Eg one battery will be 4.11v the other 2 will be 4.10v.
> 
> Lastly, make sure the batteries are the same brand and roughly the same age. I'm sure you probably used new batteries.



100% correct - I couldn't have said it better myself

Reactions: Thanks 1


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## shaunnadan

Rossouw said:


> Yes I bought all three together. I usually charge the batteries when they are just below 50%. I was beginning to worry about that difference and finally decided to get an external charger. A few weeks ago I noticed I never get a full charge anymore, always one battery sitting at 4.21 and the other two lower. Thank you! Appreciate the help.
> 
> If the batteries still show different discharge rates what should I do? Can this be a problem with the mod or the batteries?



Check the contacts and rotate the batteries. Charge all at the same time in a dedicated charger.

Reactions: Agree 1


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## Rossouw

Will do! The advice is much appreciated!

Reactions: Thanks 1


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## Christos

Rossouw said:


> Yes I bought all three together. I usually charge the batteries when they are just below 50%. I was beginning to worry about that difference and finally decided to get an external charger. A few weeks ago I noticed I never get a full charge anymore, always one battery sitting at 4.21 and the other two lower. Thank you! Appreciate the help.
> 
> If the batteries still show different discharge rates what should I do? Can this be a problem with the mod or the batteries?


That is a difficult question. 
I think you should have a good idea of the problem once you can charge them externally and see if they wear evenly. 
Perhaps label them 1,2 and 3 with a permanent marker so that you can also rotate them after a full charge I.E if 1 usually goes into the first bay put 2 into the first bay and 3 into bay two etc.


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## Rossouw

Okay will do that, can cause a bit of confusion if they are not labeled


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## Christos

Rossouw said:


> Okay will do that, can cause a bit of confusion if they are not labeled


I have tiny dot stickers. 1 sticker is 1, 2 stickers 2 etc and I have stickers inside the mod to remember position 1 and 2


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## Rossouw

Christos said:


> I have tiny dot stickers. 1 sticker is 1, 2 stickers 2 etc and I have stickers inside the mod to remember position 1 and 2


I might just steal that idea

Reactions: Like 1


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## huffnpuff

Or Use a permanent marker. As recently discovered on my cuboid, stickers make batteries wider and can cause them to get stuck in mods with low tolerances.

Reactions: Agree 1 | Informative 1


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## BubiSparks

@Rossouw - Where are you getting these readings from? If it's from the mod iteself, be aware that the RX200 is known to read these voltages incorrectly. A better bet would be is to use a multimeter or a charger that can read to 2 decimals like the Xtars or similar...


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## Silver

BubiSparks said:


> @Rossouw - Where are you getting these readings from? If it's from the mod iteself, be aware that the RX200 is known to read these voltages incorrectly. A better bet would be is to use a multimeter or a charger that can read to 2 decimals...



Funny you should say that @BubiSparks 

I noticed my RX200 readings (pressing all buttons for a few secs when off) was different to my multimeter readings when removing the batteries. Not out by much but it was different. On my RX200 readings one battery is always a bit higher even though they are nearly identical on the multimeter. 

Will note down the readings next time I take them


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## BubiSparks

@Silver. I've seen quite a difference between what the RX200 reads and when using a multimeter. There a lots of posts regarding this on international forums also.

Reactions: Thanks 1


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## Silver

BubiSparks said:


> @Silver. I've seen quite a difference between what the RX200 reads and when using a multimeter. There a lots of posts regarding this on international forums also.



Thanks @BubiSparks 
I wonder if that has any impact on the vape or the functioning of the device?
Also wonder if upgrading the firmware helps. I have not done so myself.


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## BubiSparks

Silver said:


> Thanks @BubiSparks
> I wonder if that has any impact on the vape or the functioning of the device?
> Also wonder if upgrading the firmware helps. I have not done so myself.


Yes I haven't checked since upgrading to V3.0 either. The DNA200 Rolo is spot on (+/- 0.02V) btw.

Reactions: Thanks 1


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## Silver

Will say that I wasnt overly impressed with the battery life in the RX200 on my first cycle of each set of three "brown turds" (LG HG2 I think)

First cycle I got about 13-14ml of juice - vaping at relatively lowish power of about 20-25 watts on a Crius tame build. Batts were about 3.2 volts if i remember correctly when I took them out - when it started flashing with the low batt signal.

By comparison I get 12-14 ml like clockwork on the Sig100 with two Samsung 25r batts (blue smurfs). For the Lemo1 - granted its lower power at about 15 Watts. I take the batts out when the sig reads batt at about 45% and the batts measure about 3.6 or 3.7 volts.

Hope the RX200 battery life improves with more cycles. Am on the second cycle now of the first set of three.


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## Nimatek

Not sure if v3 changes anything on the usage, will check on my next cycle.

The most important thing is rotation of batteries, the last battery sitting on the outside of the triangle is almost always never as discharged as the other two. So you need to ensure that you move them around so that one of the other two gets to that slot as well. 

If you use higher power outputs , the difference in voltage is closer. but sub 80w it seems that the last battery is not used as much.

Reactions: Agree 1 | Thanks 1


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## Silver

Nimatek said:


> Not sure if v3 changes anything on the usage, will check on my next cycle.
> 
> The most important thing is rotation of batteries, the last battery sitting on the outside of the triangle is almost always never as discharged as the other two. So you need to ensure that you move them around so that one of the other two gets to that slot as well.
> 
> If you use higher power outputs , the difference in voltage is closer. but sub 80w it seems that the last battery is not used as much.



Thanks for that @Nimatek 
Maybe at low power, it operates more like a dual battery mod - haha


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## shaunnadan

@Silver 

Just following your battery vs juice consumption comparison and was wondering if you had your 20w-25w build but ran the battery down till it gave you a check battery error and gotten as much as possible out of that batteries, do you think it would give you more ml/mah


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## shaunnadan

Silver said:


> Thanks for that @Nimatek
> Maybe at low power, it operates more like a dual battery mod - haha



Calling @Rowan Francis 

Series mod , for low power do you think it could be using the 7v circuit and once you hit a high wattage then it swaps over to the 11.1 circuit ?

Reactions: Like 1


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## 6ghost9

I just checked my batteries and I have updated to the V3 firmware. My batteries are currently reading 4.07, 4.05, 4.09. These are the green Samsung 25r batteries. They were a brand new married set and have stayed together since day 1. I run my device at a constant 50w all day and they have not died yet in a day but they wouldn't last a second so I charge them every night. While they charge I run my trusty Sig 150w. I have noticed in the past even on the Sig that my Luc v4 charger reads them sometimes at .1 difference. I hope this helps


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## Nimatek

I tend to run my RX200 till I get one line on the battery meter, then swap to my spare set. Not until the unit says "batt low". 

I get about a day and half out of a set running at 45w - 0.4ohm.

Not sure how many refills that is, I must check

Reactions: Like 1


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## BubiSparks

@Nimatek - Makes no sense electrically. If they are truly in series they should all discharge at almost exaclty the same rate.

@Silver - I too am not impressed by the battery life on the RX200. If I chain vape even at very low power (Like 15 Watts MTL), the front panel gets quite hot. The mod reports up to 65 degrees C on 10 clicks of the power button from off. Any heat that is dissipated by a component on the board is wasted energy. Lots of reports of the front panel getting warm on other forums as well. The DNA200 on the other hand is a cool customer and battery life is noticably longer on similar builds...

Reactions: Thanks 1


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## Christos

Silver said:


> Will say that I wasnt overly impressed with the battery life in the RX200 on my first cycle of each set of three "brown turds" (LG HG2 I think)
> 
> First cycle I got about 13-14ml of juice - vaping at relatively lowish power of about 20-25 watts on a Crius tame build. Batts were about 3.2 volts if i remember correctly when I took them out - when it started flashing with the low batt signal.
> 
> By comparison I get 12-14 ml like clockwork on the Sig100 with two Samsung 25r batts (blue smurfs). For the Lemo1 - granted its lower power at about 15 Watts. I take the batts out when the sig reads batt at about 45% and the batts measure about 3.6 or 3.7 volts.
> 
> Hope the RX200 battery life improves with more cycles. Am on the second cycle now of the first set of three.


The LG turds are meant give the full 3000 mah I think when they have reached 2.7v.
I read this somewhere regarding the battery. Take it with a pinch of salt because the final voltage may be incorrect due to my memory.

That being said I never discharge them below 3.5v and I get 45 to 50ml out of them at 55W.
Edit: on a dna 200.

Reactions: Thanks 1


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## Silver

shaunnadan said:


> @Silver
> 
> Just following your battery vs juice consumption comparison and was wondering if you had your 20w-25w build but ran the battery down till it gave you a check battery error and gotten as much as possible out of that batteries, do you think it would give you more ml/mah



@shaunnadan , i run the RX200 until the battery indicator starts flashing
When i take out the batts they were about 3.2V on the multimeter
Just comparing against the Sig100 2batt device, which gets me about the same millilitres of juice on only two batts and those batts are down to 3.6V. So I can tell that there is quite a difference.

This is just what i am noticing - not a major problem for me - but just reporting on it

Am hoping my two sets of "LG turds" will improve as they get more cycles. Have noticed this before with new batteries on other mods. (My turd sets have each only had their first cycle - so i need more to give them a fair chance I hope)


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## Silver

Thanks for all the feedback guys

Am starting to think the DNA200 Rolo has better battery usage/capacity than the RX200 version - just based on some of the comments

Thanks @BubiSparks - glad to know I am not alone in my findings. I do not get a hot front plate though.

Will monitor more as I go and report back on millilitre consumption per cycle - with voltage readings when taking out. My vape notes black book is getting quite crowded 

now where is that Crius, let me take a vape


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## Nimatek

BubiSparks said:


> @Nimatek - Makes no sense electrically. If they are truly in series they should all discharge at almost exaclty the same rate.



I agree completely. I have no idea how it discharges or if I am just not letting it run down enough. But the 3 cells doesn't run down the same , 2 are usually lower than the back one. I will see how it goes now. Take some photos and compare a couple of days.


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## Cave Johnson

Shoutout to @shaunnadan who answered all my battery queries via PM. Very helpful guy right here!

Reactions: Like 1 | Winner 1


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## shaunnadan

Cave Johnson said:


> Shoutout to @shaunnadan who answered all my battery queries via PM. Very helpful guy right here!



cool stuff


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## Christos

@Silver 
http://batterybro.com/blogs/18650-wholesale-battery-reviews/57179459-lg-hg2-review-20a-3000mah

Reactions: Thanks 1 | Informative 1


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## VapingSquid

Just wanted to add in regarding temperature of the unit and/or faceplate of the RX200. "Hand hot" is around 45 degrees (48+ degrees in a perfect world and tissue damage could occur) - which for components that the mod consist of (PCB, metal etc) is really not that hot. Think about your GPU (load baring maybe 70-80) CPU etc, and how those components handle the heat. Yet when we touch the heatsink - wowzers - scalding, yet little more than 45 degrees can feel too hot to touch.


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## BubiSparks

@jl10101 - While I agree that processors do run hot these days, I make sure that none of my PC components go much over 60 degrees. If they do, I buy appropriate cooling. As for mods, I own about 20 and none get noticeably warm in use. The RX200 does and it won't be the processor as it will be a very basic microcontroller. I suspect it's on the power side of things where the heat is coming from and that's not ideal in my book, especially if i'm running only 15W.

Note that I wasn't saying that the faceplate was 65 degrees. That was the temp shown by the board monitoring sensor...

Reactions: Like 1


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## Rossouw

BubiSparks said:


> @Rossouw - Where are you getting these readings from? If it's from the mod iteself, be aware that the RX200 is known to read these voltages incorrectly. A better bet would be is to use a multimeter or a charger that can read to 2 decimals like the Xtars or similar...


I got the readings from the mod itself, wil check on a multimeter when I am back home. Thanks!


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## Rossouw

I got the external charger and it is much better now, reading 4.21, 4.20 and 4.17 on the mod itself. Will check on a multimeter when I am back home, for now I am enjoying Ballito for a bit
Thanks for the help everyone!


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## shaunnadan

Rossouw said:


> I got the external charger and it is much better now, reading 4.21, 4.20 and 4.17 on the mod itself. Will check on a multimeter when I am back home, for now I am enjoying Ballito for a bit
> Thanks for the help everyone!



Cool stuff


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## Sterling Vape

On batter safety, is it OK to change the battery in my device over night?


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## Christos

Sterling Vape said:


> On batter safety, is it OK to change the battery in my device over night?


Depends on the charger. I do. My charger cuts power at 4.2v and doesn't trickle charge. 
I also set the charge to .25 A when charging overnight. 
I use a xtar vp4.


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## Christos

Rossouw said:


> I got the external charger and it is much better now, reading 4.21, 4.20 and 4.17 on the mod itself. Will check on a multimeter when I am back home, for now I am enjoying Ballito for a bit
> Thanks for the help everyone!


I'm still concerned about your batteries. 
Are they fully charged? 
My older batteries that need to be retired soon charge to 4.18v.
The fact that there is still a variation gets my spider sense tingling. 
Is that the reading on the mod or on the charger?


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## Christos

Sterling Vape said:


> On batter safety, is it OK to change the battery in my device over night?


Sorry I missed the in my device part. 
I don't see any issues with doing that just don't leave it next to your bed. There was a case of a istick that blew up and burnt the guy. 

That being said it depends if you trust your mod.
I prefer an actual charger but I do charge next to my face on my nightstand.
I do however trust my mod.

Reactions: Like 1


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## Sterling Vape

Christos said:


> Depends on the charger. I do. My charger cuts power at 4.2v and doesn't trickle charge.
> I also set the charge to .25 A when charging overnight.
> I use a xtar vp4.


Well I'm charging on through my evic vtc mini. Been doing so for the past week or so and seems OK. Just unsure if it's a good thing.


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## Christos

Sterling Vape said:


> Well I'm charging on through my evic vtc mini. Been doing so for the past week or so and seems OK. Just unsure if it's a good thing.


I honestly don't think it's a bad thing. 
I would just not discharge my battery below 3.5v.
I have used the built in charges for many a device with no problems. 
I do however still use a charger at least twice a week as I like to keep tabs so to speak on my batteries.


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## Rossouw

Christos said:


> I'm still concerned about your batteries.
> Are they fully charged?
> My older batteries that need to be retired soon charge to 4.18v.
> The fact that there is still a variation gets my spider sense tingling.
> Is that the reading on the mod or on the charger?


Yes they are fully charged, but those readings are from the mod itself and like @BubiSparks said the RX200 isnt very accurate with these things. So I will check on that when I am back home, hopefully I get a full charge.

Reactions: Like 1 | Optimistic 1


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## PrenessaM

shaunnadan said:


> Shaun’s Guide to Battery Safety
> 
> There is an incredible amount of information available for those who intend to vape at sub ohm resistances. However, there seems to be a lot of misconceptions going around about how to sub ohm safely due to some gaps in our knowledge. As a fellow sub ohm vaper I wanted to clarify a few things that seem to be frequently misunderstood about how to vape safely.
> 
> This post is geared toward those who already understand the basics of sub ohm vaping.
> 
> *Minimum safe resistance*
> 
> It seems to be very common for people to seek out batteries specifically for their high current ratings.
> 
> However, for the majority of sub ohm vapers, this high of an amp rating is unnecessary, and can even be misleading. In fact, there is a very narrow window between vaping at 20 amps (A) and vaping at 30A, and unless your coil build happens to fall within this tiny window, 30A batteries aren’t going to be much more useful to you.
> 
> Let me illustrate my point. We are all familiar with Ohm’s law: voltage equals current times resistance, or V = I*R. With a little algebra we can find out what resistance we have at a certain voltage and current, R = V/I. Using this equation we can find the minimum resistance we can build to given the current rating of the battery.
> 
> For all 18650 and 26650 batteries, the maximum voltage when charged is 4.2 volts (V). Plugging this into the equation along with the max continuous current rating of the battery will give you the absolute minimum resistance you can build to without overstressing your battery.
> 
> For a battery rated at 20A continuous, we have R = 4.2V / 20A = 0.21 ohms (Ω).
> 
> At 30A, we have R = 4.2V / 30A = 0.14Ω.
> 
> 
> *bottom line is there is a point where your build resistance needs to stop before you create a risk on your batteries even though your mod will still fire them.
> 
> *Amp ratings – continuous versus pulse*
> 
> Many people say that they can build to very low resistances because they go by the battery’s pulse rating rather than the continuous rating. It is rumoured that batteries can handle a much higher current output because of the pulse rating.
> 
> this is false.
> 
> Continuous amp ratings are the maximum current that the battery can handle discharging over a very long period of time. Pulse ratings, on the other hand, are the maximum amount of current the battery can discharge in a very short period of time.
> 
> The problem with pulse ratings is that there is no universally accepted standard for battery companies to test pulse ratings. A pulse is simply defined as a discharge in a brief time window, but there is no way to know exactly how long that pulse lasted in testing. A pulse time can be anywhere from a couple seconds all the way down to a fraction of a second – in theoretical mathematics, the time of a pulse is considered “infinitely” short.
> 
> How long do you hold the button down when vaping? Try timing it – I’m willing to bet it’s somewhere between 2 and 10 seconds. Did the battery factory time their pulse testing to accommodate that? Probably not.
> 
> Since we have no way of knowing how pulse ratings are determined, it’s safe to assume they don’t apply to vaping. It’s better to stick to the continuous amp rating.
> 
> *Batteries in pairs*
> 
> There are now many mods available that accommodate two, or more, batteries at once. There is a significant difference in performance capabilities between whether they are connected in series or parallel.
> 
> It is important that you always buy the pair of batteries used in the mod together, and always use them together and charge them together. Any difference between them can lead to one battery pumping out more voltage than the other and becoming strained. This is often referred to as “married batteries”
> 
> Batteries connected in series will retain the same current but double the voltage. For instance, if you use two 20A batteries, you will still have a max current discharge of 20A, but you will have a max voltage output of 8.4V. This is helpful if your goal is to maximize power, or wattage (W), without decreasing the resistance of your build.
> 
> In fact, this will increase your power by a lot. Power is equal to the voltage times the current, or P = V*I. If you use 20A batteries and build to the lowest resistance possible, your power from one battery at max voltage is 4.2V * 20A = 84W. If you stack two of these batteries, however, your power is now 8.4V * 20A = 168W!
> 
> Many people who stack batteries find that they prefer building their coils to a higher resistance because of this.
> 
> Batteries wired in parallel will retain the voltage but double the current. So now if you use two 20A batteries, you will retain a voltage of 4.2 but have a max continuous current of 40A. This allows you to lower the resistance of your build.
> 
> If you pair two 20A batteries, your minimum resistance is now 4.2V / 40A = 0.11Ω. If you pair two 30A batteries, your minimum resistance becomes 4.2V / 60A = 0.07Ω!
> 
> That’s about as low as it gets. If you plan to build to extremely low resistances, I highly recommend buying a box mod that runs batteries in parallel.
> 
> *Regulated Mods Internal Safety Mechanism*
> 
> A lot of people would say they don’t worry about what they build because their mod will protect them. It will give you an error when you going wrong. I fully agree that this will happen for errors like short-circuits, reversed polarity, and when exceeding the chipsets lowest resistance.
> 
> But not all mods are created equally and I have seen me far share of mods DIE a slow and painful dealt because of incorrect batteries and unsafe builds.
> 
> My intern is a very dumb person. He got himself an IPV3 li and then instead of buying a pair of decent batteries he went to the china mall and got himself a pair of ultrafire 18650’s because it’s the same thing as his father’s torch and only cost R20.00 each! He then built a Clapton build and pushed his to 100W. After a few min he started to feel his mod vibrate in his hand, smoke started to pour out of the batteries as it leaked and then bang! His mod had melted.
> 
> My personal legendary sigelei 150w however had a different story. I had built a super sub ohm coil. 0.12 ohm resistance and was firing it at 150w. Once the battery got to 80% it refused to fire and had the check battery message. So I took the batteries out and placed them into the snowwolf with the same atty and it fired. So I kept vaping for another 5min and then the front panel of the snowwolf started to get very hot especially where the buttons were. There was a feeling of a relay clicking inside the mod each time I fired it and I then decided to stop playing around and packed it all away.
> 
> There was something in the chipset of the segelei that refused to fire the mod when the batteries got too low to power that coil but not in the snowwolf.
> 
> The most important thing is to check what mod you have, then consider what batteries your using and look at the ohms law chart and see what’s your lowest available resistance. I very often choose to build lower than what is recommended for me and push higher power than I should but I do it with full knowledge of the risks and have only myself to blame if something goes wrong.




I have a question.... did you type this entire thing on your phone? cause that would explain so much, and also quite impressive.

Reactions: Winner 1


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## Kuhlkatz

PrenessaM said:


> I have a question.... did you type this entire thing on your phone? cause that would explain so much, and also quite impressive.



Lol, @shaunnadan , she's onto you... Better hide that phone when HRH is present

Reactions: Funny 1


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## shaunnadan

PrenessaM said:


> I have a question.... did you type this entire thing on your phone? cause that would explain so much, and also quite impressive.



ipad

Reactions: Like 1


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## korn1

Hey guys,still wondering if this is safe (sorry) 2.5V - O.6 OHMS -10 Watts on a Samsung INR18650-25R 2500mAh


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## Kuhlkatz

Safe.. Yes, ample. The 25R is rated at 20A continuous discharge rate (CDR).

Assuming a single battery mech mod: When calculating, always use the max voltage of a fully charged battery , which is 4.2 V :
I = Current in Amps
E = Voltage
R = Resistance
P = Power in Watts

Ohms Law (some of the calcs)
I = E / R and 
P = E * I once I is known

So using 4.2V & 0.6ohms :
4.2 / 0.6 = 7 A
4.2 * 7 = 29.4 W

Or just plug in any 2 values in an online Ohms Law calc :
http://www.ohmslawcalculator.com/ohms-law-calculator
http://www.onlineconversion.com/ohms_law.htm

and then check the current draw against max rated battery specs using Mooch's list in the PDF :
https://www.e-cigarette-forum.com/forum/attachments/moochs-battery-safety-grades-pdf.514437/

Reactions: Like 5


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## Neal

Hey @shaunnadan, thanks for excellent post. Mate, please excuse my ignorance here, but you seem to be the best guy to turn to with queries on batteries. I got myself a 4 bay charger yesterday, can charge at 0.25, 0.5, 1.0 and 2.0. Am running 3 x HG 2 and a 25R. Am I correct in thinking 1.0 is best charge on these batteries? Thank you


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## Christos

Neal said:


> Hey @shaunnadan, thanks for excellent post. Mate, please excuse my ignorance here, but you seem to be the best guy to turn to with queries on batteries. I got myself a 4 bay charger yesterday, can charge at 0.25, 0.5, 1.0 and 2.0. Am running 3 x HG 2 and a 25R. Am I correct in thinking 1.0 is best charge on these batteries? Thank you



Quick and short is that the slower the batteries charge, the longer they will last. In theory. 
The faster you charge the batteries the less their lifespan will be. 

That being said, I still charge at 1 amp.
I drop too 500mA when I charge overnight. 

I would suggest you try not use the 1 amp unless you are in a hurry.

Reactions: Agree 3 | Thanks 1


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## Raks92

I have vaping at 120w on my Rx200s with the LG chocolates. Is this safe?


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## Feliks Karp

Raks92 said:


> I have vaping at 120w on my Rx200s with the LG chocolates. Is this safe?



For a regulated mod, you take the wattage and it divide it by the batteries voltage to get the amp draw. For this you use the minimum voltage you expect to get to on the battery, so that you know that you are safe from using that battery when its fully charged down to when it's "empty". 

I like to stop using my batteries when they hit the 3.4 v mark, so ((120 watts / 3)/3.4 v) = 11. 76 amp draw on each battery, LGs are rated for a CDR of 20 a, you're fine (assuming that the batteries are 100% healthy). Even if you used the batteries down to 3.2 v you'll be ok with a 12 a CDR. I used 3 here because the rolo has 3 in series, if the mod was a 2 bat mod you'd just substitute the 3 with 2, so ((120 watts/2)/3.4 v) = 17 a, still a safe draw for LG's but approaching the red line.

Reactions: Agree 1


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## Raks92

Feliks Karp said:


> For a regulated mod, you take the wattage and it divide it by the batteries voltage to get the amp draw. For this you use the minimum voltage you expect to get to on the battery, so that you know that you are safe from using that battery when its fully charged down to when it's "empty".
> 
> I like to stop using my batteries when they hit the 3.4 v mark, so ((120 watts / 3)/3.4 v) = 11. 76 amp draw on each battery, LGs are rated for a CDR of 20 a, you're fine (assuming that the batteries are 100% healthy). Even if you used the batteries down to 3.2 v you'll be ok with a 12 a CDR. I used 3 here because the rolo has 3 in series, if the mod was a 2 bat mod you'd just substitute the 3 with 2, so ((120 watts/2)/3.4 v) = 17 a, still a safe draw for LG's but approaching the red line.


Thanks buddy


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## Umar Osman

Hi Bro 
Just a quick question what will be good batteries to use on a twisted messes 150w mod?? 
And how long lifespan would you get off batteries. I own a rx200 n twisted messes mod. Very very seldom would I ramp up to around 100-180 watts whilst dripping. I run most of the time at 50- 60 watts


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