Question on calculating amps drawn on batteries

[johnnyyjung]

Hi guys. I've been browsing this forum for over a year or so and have learned much here. Haven't had any questions until now, so I'm coming to you guys for help.

I understand how Ohm's law works and how it applies to mech mods (what I started on), but I am interested in getting a regulated device such as an IPV3 or a sigelei 100W. I'm planning on using the regulated device with 2 new Sony VTC4's.

Right now I am confused with how the adjustable wattage and dual batteries comes into play when calculating amperage. Do I just divide the voltage by the resistance (V/R) to get the amps, or do I divide the wattage displayed on the screen by the resistance (Watts/Resistance)^(1/2)?

Any help would be appreciated greatly because I'd prefer to vape safely.

 

[invisiblehand13]

If you get either a sigelei 100 or a ipv3 they both will do the work for you as long as you build within 0.15-3.0 ohms, the chips do all the work for you and all you have to do is set it to whatever watts you wish to vape at but if you would like a vape calculator I really like this one... vapecalc.com

 

[invisiblehand13]

I rock my sigelei 100 with a .15 build at 91 watts all day...never a problem, ipv3 is also good but IMO I like the sig better...

 

[invisiblehand13]

Oh but for either of these aforementioned boxes you will need good batteries, this is my trusted list I use, some will disagree but I have used and do use all of these with no problems...

VTC line (of course, duh lol)
LG HE2
LG HE4
MXJO yellow 35 amp
Purple efest 35 amp
Samsung 25r

All good enough for this application IMO, but with these boxes you will need "married sets" which charge together, go in together, and come out together to return to charge together...I am OCD on the rotation of insertion side as well but I have been hearing that is not as important as was once thought...oh well, I already do it

 

[readeuler]

rusirius has been taking the lead with info on the electronics of regulated mods.

But from what I recall, you want to be using the wattage. I wish I could recall how it all works out, but I know that as long as you're pushing a certain wattage, the resistance is irrelevant to the amperage.

I dare say you use battery (not mod) voltage and mod wattage to calculate the amperage. Possibly nominal battery voltage, but don't quote me on that

ETA: here's a link to rusirius dropping some knowledge, although it's really in reference to battery life on a regulated device, not exactly amp draw (although the two are clearly related)

http://www.e-cigarette-forum.com/forum/showpost.php?p=14646087

Unfortunately, it's too late for me to say exactly how this answers your question, but I have a feeling it explains something relevant, somehow

 

[johnnyyjung]

So I caved and finally bought an IPV3 as well as 2 VTC4's as an early Christmas present to myself. 2 more Samsung 25r's are on the way from Illumination supply as I write this out.

I do plan on marrying the sets and rotating them with every charge cycle so that I can vape as safely as possible.

I'll continue looking for the answer, and when I find it I'll get back to this thread.

Thanks for all the help guys!

 

[Rwb1500]

So I caved and finally bought an IPV3 as well as 2 VTC4's as an early Christmas present to myself. 2 more Samsung 25r's are on the way from Illumination supply as I write this out.

I do plan on marrying the sets and rotating them with every charge cycle so that I can vape as safely as possible.

I'll continue looking for the answer, and when I find it I'll get back to this thread.

Thanks for all the help guys!

Sounds like a good plan, congrats on the new toy!

Where in the world did you find VTC4s?

 

[The Ocelot]

Perhaps you might find this useful. I know there are Ohm's Law calculators around, but I learned using a power wheel (which depicts Ohm's Law and Watt's Law).

P (Power) = Watts
V = Volts
I (Intensité/Intensity) = Amps/Current
R (Resistance) = Ohms

Since I have used a VV device for so long this is how I have it memorized:
Voltage x Voltage ÷ Resistance = P (Wattage)
Then, Wattage ÷ Voltage = I (amps)

ETA: I'm looking through my files for the info on dual batteries.

A parallel connection is made by connecting like terminals of two or more batteries together (i.e. positive to positive and negative to negative). This increases the amperage of the circuit (the AH capacities of the batteries, or strings of batteries, are simply added together) while keeping the total voltage the same as one of the batteries, or paralleled strings of batteries, in that bank.
The diagram shows two 12V batteries that are paralleled together. The total voltage of this battery bank is 12V. If each battery is rated at 250AH, the AH capacity of the battery bank is 500AH, since amperages, not voltages, add together in parallel wiring.¹

In short:

• Connecting batteries in parallel increases total current capacity by decreasing total resistance, and it also increases overall amp-hour capacity.
• All batteries in a parallel bank must have the same voltage rating.²

1) http://www.solarray.com]Colorado Solar Energy Systems. Solar Power for Residential Homes.
2) http://www.allaboutcircuits.com/]All About Circuits : Free Electric Circuits & Electronics Textbooks

 

[AndriaD]

There's also Steam Engine | free vaping calculators for those like me who go cross-eyed with all that math.

Andria

 

[JeepyG]

I like to use the calculator at the link below.
Simple and straight forward... no fuss.
http://www.sengpielaudio.com/calculator-ohm.htm

 

[The Ocelot]

I'm not sure the online calculators would answer the OP's question, since he was asking about 2 batteries. My Power Wheel doesn't take 2 batteries into account and I don't think the calculators do either - I could be wrong though, I use single batteries.

I may have been incorrect in assuming the batteries are wired in parallel. If they are wired in series, I have that info too.

 

[johnnyyjung]

Ocelot - From what I've read, the IPV3 batteries are in series.

 

[The Ocelot]

Ocelot - From what I've read, the IPV3 batteries are in series.

Ok - give me a minute.

 

[The Ocelot]

Ok - give me a minute.

A series connection is made by connecting one pair of opposite terminals of different batteries together (i.e. positive to negative). This increases the total voltage (the voltages of the two or more batteries are simply added together), while keeping the amperage capacity the same as just one of the batteries that are wired in series. Chances are you've been making series connections all your life -- flashlight batteries are put end to end, nose (+) to .... (-).

The diagram below, shows 2 batteries connected together in series. This is one "string." Since these are 6V batteries, the nominal voltage of this string is 12V. If each battery is rated at 220AH, the AH capacity of the entire string is still just 220AH, since voltages, not amperages, add together in series wiring.¹

In short:

• Connecting batteries in series increases voltage, but does not increase overall amp-hour capacity.
• All batteries in a series bank must have the same amp-hour rating.²

1) http://www.solarray.com]Colorado Solar Energy Systems. Solar Power for Residential Homes.
2) http://www.allaboutcircuits.com/]All About Circuits : Free Electric Circuits & Electronics Textbooks

 

[invisiblehand13]

If the OP goes with a regulated device than the math really doesn't matter IMO, the chip does all the work for you and you just have to build within the resistance limits of the chip, if you build too low or too high the chip simply says..."no" and will not do anything until you fix the issue, the extra math is good if you wanna be OCD about it but in all reality that is why the chip is there for you...to take all the math and guesswork out of the equation. Plus they run these china made box mods (regulated ones at least) in series because it is more efficient for the chip to step down the voltage from it's stacked 8.4 volts down to whatever is required to run the set/requested watt setting. I used to be all about my single battery mech mods, then I found my parallel wired dual batt mech mod boxes and now I have my dual batt regulated boxes so I have less and less to worry about with my sub ohm builds...In short I love my sig and my ipv3 lol

 

[edyle]

Hi guys. I've been browsing this forum for over a year or so and have learned much here. Haven't had any questions until now, so I'm coming to you guys for help.

I understand how Ohm's law works and how it applies to mech mods (what I started on), but I am interested in getting a regulated device such as an IPV3 or a Sigelei 100W. I'm planning on using the regulated device with 2 new Sony VTC4's.

Right now I am confused with how the adjustable wattage and dual batteries comes into play when calculating amperage. Do I just divide the voltage by the resistance (V/R) to get the amps, or do I divide the wattage displayed on the screen by the resistance (Watts/Resistance)^(1/2)?

Any help would be appreciated greatly because I'd prefer to vape safely.

2 batteries, in a 100 watt mod.
That means each battery has to supply 50 watts;
I'll use 60 watts conservatively

minimum battery voltage: I'll use 3 volts conservatively.

watts = volts x amps

amps = watts/volts = 60/3 = 20 amps

So the batteries have to supply at most 20 amps to the input of the mod electronics.

The output side is a different story but I assume its the input side you're interested in for battery reasons.

 

[edyle]

Ocelot - From what I've read, the IPV3 batteries are in series.

All the current high powered mods that I have found use series (stacked) battery configuration.

The only parallel configurations I've seen are mechanical box mods.

 

[johnnyyjung]

So, since the chip does all the work, why does Pioneer4you recommended that we use only 30amp continuous batteries?

Is it so we can use the full wattage range? Or is it for safety reasons? Up to now, I've been under the impression that it was due to safety only.

 

[edyle]

So, since the chip does all the work, why does Pioneer4you recommended that we use only 30amp continuous batteries?

Is it so we can use the full wattage range? Or is it for safety reasons? Up to now, I've been under the impression that it was due to safety only.

The mod doesn't know if you put in a battery that might vent on you; if you use the wrong kind of batteries, and try to run high wattage, the mod will try to draw high wattage from the battery, and if the battery gets hot and runs into thermal runaway you get some excitement you could do without.

 

[invisiblehand13]

So, since the chip does all the work, why does Pioneer4you recommended that we use only 30amp continuous batteries?

Is it so we can use the full wattage range? Or is it for safety reasons? Up to now, I've been under the impression that it was due to safety only.

Good question, you are using stacked batteries, that first of all is dangerous and unadvised in anything other than a regulated device, and they still need to be high drain and high amp batteries due to the sheer amount of power being requested from them. True, the chip does all the work (and I think some of them detect when you are not using the correct batteries and simply will not work above a certain wattage until you replace them with 30 amp batteries) if you have the correct batteries, this is why I provided my list of trusted batteries for these devices first and foremost so there would be no confusion with this topic. They recommend 30 amp batteries to run these things but they know that everyone will be using their china rewrapped 20 amp continuous batteries lol, anyways, just to try this out I got some of my old ten amp batteries and tried them out and they just kind of petered out and stopped firing around I think it was 60 watts on my sig but it just stopped firing or firing sparodically due to the chip kicking in and saying "no" just like if I keep it at 91 watts on my good batts once they get down to like 40% battery they do the same thing unless I turn down the watts. So yes, the chip does all the work but if you want to be COMPLETELY safe and use the mod in its full functionality then you can only use VTC's if you want to get technical but I have used all on my list in my IPV3 all the way up to 150 (no firmware update on mine yet, new limit is 165 I think) with no issues other than decreased battery life/run time...