Single vs. Multi Battery Mods

[Dela Rey Steyn]

In an UNREGULATED mod, the battery life would be the same between a series cell configuration and a single cell configuration and increase with a parallel cell configuration.

In a REGULATED mod, Dual Batteries, whether Parallel or Series, WILL give you more battery life than a single cell mod, WHEN using the same Coil and Power/Wattage on either mod.

 

[Stranger]

This is so confusing..
The question begs then...
If dual battery mods in series (literally 99% of mods on the market) gives same battery life as a single battery mod then have we as consumers been taken for ride and exploited.

Why would manufactorers then even realise a dual battery mod in series other than for financial gain, and, why would we as consumers even purchase them given their price compared to single battery mods

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After further investigation, I concede that you are right and I am wrong on the point of battery boxes being mostly series wired. There must indeed be some seriously dark magic going on for the chips to convert the energy flow the way they are doing. Every thing I know points to the basics, yet these mods are doing the opposite.

The below even contradicts what we have been discussing

BATTERIES IN SERIES

Essentially this means your battery terminals connect positive to negative.

The combined voltage of the two vape batteries in this configuration is the sum of the individual batteries. This basically means you’re increasing the voltage of your battery supply when using batteries in series.

However, the current (mAh) and Continuous Discharge Rate (CDR) is that of the single battery.

The advantage of this setup is that it provides additional voltage and greater power to the coil, increasing vapor production!

BATTERIES IN PARALLEL

The opposite of batteries in series, your battery terminals connect positive to positive and negative to negative.

The combined voltage of the two batteries in this configuration is that of the single battery. The current (mAh) and Continuous Discharge Rate (CDR) is the sum of the two batteries.


The advantage of this configuration is to enable increased (twice the capacity) current. This will result in the combined battery current lasting twice as long as that of a single battery. In layman’s terms, your vape mod will run for double the time before you need to re-charge the batteries.

Furthermore, the CDR of each battery is doubled. This can have two possible advantages:

1. With two batteries, each having a CDR of 20 Amps, the overall CDR will be 40 amps. This will allow for a lower resistance coil build, enabling higher current to be drawn from the combined batteries.
2. If your coil build and battery voltage is such that the current drawn from the combined batteries is 20 Amps, you can use two 15 Amp batteries. This means you can use two lower spec batteries to achieve your required CDR value for your vape build.

 

[Stranger]

So based on the above research, we are right when it comes to unregulated mods but wrong when it comes to regulated.

 

[Intuthu Kagesi]

So based on the above research, we are right when it comes to unregulated mods but wrong when it comes to regulated.

Spot on

I'm grateful for the info ... Thanks everyone
I posted the statement "I'm curious as to why the proliferation of Series Dual and Triple Battery Mods, and not Parallel Dual and Triple Battery Mods in the market", as I'm busy with an Arduino Nano powered TRIPLE parallel build, that's now about to change to a series triple mod, as that also resolves my need for a separate buck/boost circuit for the processor, (5V required for the processor).

 

[DougP]

Okay now that we have sorted this little debate out can we now tell @Dela Rey Steyn to stop chain vaping himself to death to get us a practical demonstration of battery life in his single and dual mods.

The poor guy is gonna get a nic overload.


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[Intuthu Kagesi]

Okay now that we have sorted this little debate out can we now tell @Dela Rey Steyn to stop chain vaping himself to death to get us a practical demonstration of battery life in his single and dual mods.

The poor guy is gonna get a nic overload.


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Say what you may ... This man is dedicated to a cause!

 

[Dela Rey Steyn]

Say what you may ... This woman is dedicated to a cause!

Woman? I better tell SWAMBO she is a lesbian now....

 

[Intuthu Kagesi]

Woman? I better tell SWAMBO she is a lesbian now....

Ooooooops ... Sowwie

 

[DougP]

Say what you may ... This man is dedicated to a cause!

For the love of Gawd then let's not start a thread about how sensitive vibrators can get... Given this mans dedication to the cause I can just imagine what will happen

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[Intuthu Kagesi]

For the love of Gawd then let's not start a thread about how sensitive vibrators can get... Given this mans dedication to the cause I can just imagine what will happen

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We can move the debate to parallel vs. series cell vibrators ... speed vs. longevity

 

[DougP]

Woman? I better tell SWAMBO she is a lesbian now....

OLala has Dela Rey Steyn finally come out of the closit. I would have never guessed that transgender operation was very well done
So you gonna change nick to
Dela Liscious Samantha


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[DougP]

We can move the debate to parallel vs. series cell vibrators ... speed vs. longevity

Yes yes great idea
Oh Mr Steyn you care to test for us

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[Dela Rey Steyn]

Yes yes great idea
Oh Mr Steyn you care to test for us

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No need for new tests... there is past data....

 

[Stranger]

Okay now that we have sorted this little debate out

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This debate is far from over, this is ELECTRICKERY ............... we need answers dammit.

 

[Resistance]

According to me an unregulated series mod wil convert energy from volts instead of Amps
And vise versa for an unregulated parallel mod.
But that's according to me.

 

[Silver]

We are talking regulated mod theory only I take it.
In your example you assume that the PWM output is 'always on'. For PWM this is not true as the duty cycle is a series of swithed on full and switched off full cycles where the 'ON' cycle determines how much power is effectively delivered. A 50% duty cycle should equate to roughly 50% of what the battery can provide. It would also mean that max current is not drawn from the battery all of the time, as the coil does not see 'all the power' all the time. It is switched on and off for short periods of time and an 'average' amount of power is spread out based on the duty cycle.
PWM circuits typically supply a lower voltage than the input voltage, so for mods, typically below 4.2v. Using multiple batteries in series means that the total effective voltage at the output can be stepped up as well - 4.2v, 8.4v. 12.6v etc.

Using your example with Ohm's Law to calculate a few things in reverse, we have :
Power = 15w
Resistance = 0.5 ohm
So current through the coil should be 5.477A - check.
Voltage across the coil should be 2.738V - check.

Battery = 3.65V
Resistance = 0.5 ohm
So current should be at 7.3A ? - not check.
Power should be 26.645W ? - not check.

Is the PWM circuit just dissipating 11.645W into heat energy and drawing an extra 1.8A just for switching stuff off and on?
This is likely not the case, or if it was, nobody would use PWM in any application as it does not seem to be very efficient.

The snag here is that it is not just a simple series circuit. Using your example, and a perfect world scenario, let's check it again but at 65 Watts, which we all know a single 18650 mod should be capable of.
To produce 65 Watts across a 0.5 ohm coil, the Ohm's Law calculations would have the voltage across the coil at 5.7v and the current at around 11.4A. But yet we only have a fully charged single battery of 4.2v.

Now we know the battery is definitely at 4.2v and that we are producing 65W of power across the coil. Using Ohm's Law again, this now calculates that the current should be at around 15.476A. Huh?
This suddenly does not equate, as either Ohm's Law has been totally stuffed since inception, or we have some serious Devil's magic happening here.
View attachment 209013
You cannot measure it as simple as you have, as the input (battery side) and the output (coil side) are not directly connected. There are other discrete components that switch on and off for simple PWM so the current across the coil is an average of the full on / full off duty cycles.
For Buck and Boost circuits there are also discrete components that switch on and off but also store and provide either reduced or increased power to the output in the place of the battery. The switching rate and power gained or lost is just governed by some clever monitoring done on top of the buck or boost to retain the output within the parameters you set via the interface, be it Volts, Watts, or a specific temperature.

For regulated mods, if you assume that the circuitry is 100% efficient, do the calcs for the COIL side separate to that of the BATTERY.
Using what we know of the OUTPUT or coil side:
Power = 15W
Resistance = 0.5 ohm
Current is then 5.477A through the coil
Voltage should be 2.739V across the coil.

Using what we know on the INPUT or battery side:
Power = 15W
Voltage = 3.65V
Current drawn from battery = 4.11A

Obviously this is in a perfect world, so depending on efficiency of anything between 90-95%, you can add the additional 5-10% to the current drawn and actual Power dissipated on the INPUT side of the equation to determine safe limits.

If you can calculate the current drawn from the batteries based on their capacity and the input voltage you can easily prove that dual batteries in a series or parallel configuration will effectively last twice as long as a single battery counterpart. Taking your battery at 3.65v (or 2 at 3.65V) , 0.5ohm coil and 15W as an example:
View attachment 209030

The actual time may not be 100% accurate as time remaining at 3.3V is still theoretically 33 minutes, which means that from 4.2 volts, you should get around 9-10 minutes of continous vaping till the batteries reach the 3.3V cut-off.
The reduced current draw from using 2 series batteries with a higher input voltage or using 2 parallel batteries providing double the mAH capacity, does support the increased vaping time if you look at the figures.

9-10 Minutes of ~ 2 second puffs = 270 puffs, which seems about right. 540 for a dual battery.
9-10 minutes of ~ 3 second puffs should be around 180. 360 for a dual battery.

So, who's counting puffs that can back this up?

For a 2500 mAH battery, you can theoretically provide 10.5 Watt of power one full hour before the battery goes to 0v. But then we don't use them down that low do we.

thanks for the detailed response and explanation @Kuhlkatz !!

 

[Puff the Magic Dragon]

The poor guy is gonna get a nic overload.

Just a slight correction.

We don't recognise descriptions like nic overload.

It is called doing a Silver.

For those of you who don't know about this @Silver became infamous for doing this when he was a noob.

 

[Dela Rey Steyn]

After reevaluating my experiment parameters. I started a fresh with a lower build on my Rebirth RTA and 3mg Taviro, which from experience I know I can vape on the WHOLE day.
Drag X:
Started with a fully charged Molicel Battery and reset the puff counter.
It picked up the atomizer resistance as 0.2ohm



Reached 174 puffs before the battery indicator turned red.

Argus GT:
Started with a fully charged married set of Molicel Batteries and reset the puff counter.
It picked up the atomizer resistance as 0.21ohm



Got to a total of 332 puffs before the battery indicators turned red.

 

[Stranger]

I think I know how they are doing it.

In the same way that the chip will allow for balanced charging through the USB, I think that they chip is also compensating for a balanced discharge from each cell. This would not work if they were simply stacked like a boom stick, but now makes sense.

I have seen a few comments on mods where the battery indicators on a dual are not discharging at the same rate and when the one is empty, the mod will not fire even if the other one reports full. This then explains that if that function is not working correctly, you will not get the balanced discharge. In effect it separates the batteries then reconnects them drawing only what is needed in terms of W and amps. Push the Volt demand over what the battery is capable of, for example you can't get 5 V from a 3.7 V battery, 4.2 at the most and then the dual batteries will combine to supply the required Volts.

It is just a theory, came to me in a dream last night, just before the two Japanese models.

 

[X-Calibre786]

This thread reminded me of something sort of related that I've wanted to discuss. Should probably start a separate thread though.

 

[Puff the Magic Dragon]

I better tell SWAMBO she is a lesbian now....

Do you intend to stop vaping if you get pregnant? IMO this would be essential.

 

[Intuthu Kagesi]

I think I know how they are doing it.

In the same way that the chip will allow for balanced charging through the USB, I think that they chip is also compensating for a balanced discharge from each cell. This would not work if they were simply stacked like a boom stick, but now makes sense.

I have seen a few comments on mods where the battery indicators on a dual are not discharging at the same rate and when the one is empty, the mod will not fire even if the other one reports full. This then explains that if that function is not working correctly, you will not get the balanced discharge. In effect it separates the batteries then reconnects them drawing only what is needed in terms of W and amps. Push the Volt demand over what the battery is capable of, for example you can't get 5 V from a 3.7 V battery, 4.2 at the most and then the dual batteries will combine to supply the required Volts.

It is just a theory, came to me in a dream last night, just before the two Japanese models.

Were said Japanese models battery powered? ... and if so ... Were they Parallel or Series?


What I have seen on an oscilloscope is that the full battery voltage, (minus the miniscule voltage drop over the mosfet and a low value resistor that is used for current measurement/ feedback to the processor), is available on the 510 connector ...
It seems the processor measures the current via voltage drop over the aforementioned resistor, and then adjusts the pulse width. So technically you have much higher voltages and currents at the 510 connector, albeit for short pulses, giving an average voltage / power much lower than the instantaneous values.

 

[Stranger]

Nah, they were either petrol or diesel but they did win a shitload of Paris/Dakar