Watts/Volts/Amps Maximizing Battery Life

[junkman]

OK, so I have a new Spinner 1300mah battery. I am running a DID clone on it at about 1.7ohms. The battery is not lasting as long as I hoped.

So, reading a bit, I got tangled in watts/amps/volts/ohms and such.

So, I have been running my Spinner at about 4 volts. My coil is about 1.7 ohms. The ohm calculator tells me I am running about 9.4 watts. Also, it tells me I am running 2.35 amps. This is giving me about 6-7 hours on a charge.

My question is, if I increase the resistance of my coil to 2ohms and increase my volts to 4.7 (and thereby maintaining 9.4 watts and reducing the amps to 1.53) has this improved my battery life while providing the same experience?

Is amps the thing that determines battery life or is volts? They are moving in opposite directions when I increase resistance.

Hope this makes sense. Just really would like to get the spinner to make it through the work day!

 

[Hoosier]

Sorry, the power has to come from somewhere and the battery is the only place it can come from.

While the voltage going up and the current going down at the output would seem to make for a longer lasting battery, that extra voltage is not produced by the battery. It is produced by a circuit that "tricks" some of the current into more voltage. (Tricks is the quickest non-technical thing I could come up with at the moment for what is actually happening.) There are inefficiencies associated with this "trick" so it actually takes a bit more power from the battery than can be used at the output/coil.

Basically your battery has so much power. It is rated at mAh for a certain current drain at the battery voltage as should be a reference to the amount of power it can contain. Power is power, there is no way to trick it higher.

 

[junkman]

Ah, damn the laws .

So, really, boosting to 4.7 volts may actually hurt as the trick to get the volts may consume more than the volts produced?

 

[Hoosier]

Ah, damn the laws .

So, really, boosting to 4.7 volts may actually hurt as the trick to get the volts may consume more than the volts produced?

I cringe, but I think you have the general idea. There are a number of basic buck / boost circuits and each one has advantages and drawbacks, but all of them have some inefficiencies. (Which means heat and sinking calculations for the designer, but is meaningless to the end user.)

 

[Black Strat]

Sorry, the power has to come from somewhere and the battery is the only place it can come from.

While the voltage going up and the current going down at the output would seem to make for a longer lasting battery, that extra voltage is not produced by the battery. It is produced by a circuit that "tricks" some of the current into more voltage. (Tricks is the quickest non-technical thing I could come up with at the moment for what is actually happening.) There are inefficiencies associated with this "trick" so it actually takes a bit more power from the battery than can be used at the output/coil.

Basically your battery has so much power. It is rated at mAh for a certain current drain at the battery voltage as should be a reference to the amount of power it can contain. Power is power, there is no way to trick it higher.

Good explanation. Whether or not you are an electrical engineer or understand the theory, just remember nothing is for free!

 

[MorpheusPA]

Really, it's easier to think of as:

watts = volts * amps

Raise the volts, lower the amps to keep the wattage the same. Raise the amps, lower the volts to keep the wattage the same.

(Sidenote: We already know that V = IR, or voltage = amps * resistance, so that's where your coil resistance comes in and that's already taken care of above if you work out the volts and amps, and also where the P = I^2*R equation comes from).

Off the cuff, figuring the battery's natively an average of 3.5 volt or so (give or take over the whole battery life, it doesn't really matter as long as I'm close), you have 3.5 * 1.3 = 4.55 watt-hours in that battery. Or, you could draw 4.5 watts for 1 hour, 9 watts for a half an hour, and so on. I'm probably a bit low on that but it keeps the math easy.

Very roughly. How fast you drain a battery and the pattern of draining it does change when the battery says its empty. Our patterns are intermittent so we tend to get good battery life compared to a constant heavy drain.

Ignoring the conversion in the boost-buck controller (efficiencies range from about 65% right on up, and 65% these days would be pretty poor conversion), 4.5 watt-hours in the battery divided by your 9.4 watt sweet spot means you'll get a bit less than half an hour of constant usage from the battery.

 

[junkman]

So it basically comes down to the vaping experience is driven by watts more so than volts and ohms, and also battery depletion is driven by watts more so than volts and ohms

 

[LucentShadow]

So it basically comes down to the vaping experience is driven by watts more so than volts and ohms, and also battery depletion is driven by watts more so than volts and ohms

Well, Watts are the product of your involved voltage and resistance (P = E * E / R), so the two sides of that equation are necessarily equal.

The main confusion is that battery makers use the incorrect unit to rate the batteries. Watt-hours would be more appropriate than amp-hours.

 

[junkman]

Yeah, I just meant that saying how many volts your running or what your ohms are doesn't tell you what you need to know, and, within reason at least, just saying the watts you are running does tell you all you need to know, regardless of the volts/ohms.....within reason anyway. And now I understand that goes for not only the vapor coming off your coil, but also the energy coming off your battery.

 

[MorpheusPA]

Yeah, I just meant that saying how many volts your running or what your ohms are doesn't tell you what you need to know, and, within reason at least, just saying the watts you are running does tell you all you need to know, regardless of the volts/ohms.....within reason anyway. And now I understand that goes for not only the vapor coming off your coil, but also the energy coming off your battery.

Within reason. They couldn't sell an atty at a given number of watts since it depends on your voltage. So, accurately, they tell you the resistance. The combination of your battery's and e-cig's resulting voltage and your atty's resistance equals the wattage at which you vape.

Watts = heat production = vapor, and within any reasonable range that will be a pretty linear relationship. Double the watts, double the vapor--roughly. Outside of reasonable range you'd either get no or very little vapor (cold, low wattage end) or a burned taste as the atty dries out (hot, high wattage end). Half a dozen people out there are cringing because there will be a perfect point where liquid feed is exactly correct and vapor production maximized, but it's close enough for most of us.

 

[AttyPops]

Vape at lower watts. Different atomizers may have a bit different coil surface area too, and that might help you lower the heat a bit.

Also, it MAY be that the device is more efficient when bucking (reducing voltage) that boosting (upping it past 3.6 ish). So.... the LR coil you have at, say 3.5v to allow for losses, may last longer.

I say this because many of us gear heads have been kicking this around various ways, but experiential results from eGo Twist users seem to indicate that reducing the voltage extends battery life more than any theoretical gains from boosting voltage all the way up (Higher voltage is more efficient in it's work...not accounting for other losses, like from boosters.)

IDK if your device behaves like a twist...as has been explained above...there are different design options. But....may be worth a try.

 

[junkman]

Vape at lower watts. Different atomizers may have a bit different coil surface area too, and that might help you lower the heat a bit.

I find 9-10 watts works best for me so I probably won't lower the watts. I got a VV device to be able to dial this in, so if I find that my battery life sucks, well, I will just need more batteries.

My concern was I felt like 1300mah should be lasting longer, but if not, then nothing I can do about that.

 

[Boden]

Junkman,

I keep seeing people using 9+ Watts. Every time I try that it's too hot. What are you using that allows that? (atty, cart, etc)

Anyone else doing this please advise.

Thanks,
Boden

 

[steved5600]

Here is a spread sheet that will figure watts for you and a useful chart.
View attachment 144463View attachment electronic calcs.xlsx

 

[junkman]

Junkman,

I keep seeing people using 9+ Watts. Every time I try that it's too hot. What are you using that allows that? (atty, cart, etc)

Anyone else doing this please advise.

Thanks,
Boden

I am using a DID clone on a Vision Spinner. My current coil started at about 1.7ohm and was vaping at about 4 volts, but the resistance is creeping up. I just checked and it is about 2.0 ohms now, which is why I suppose that I have been bumping the volts up a bit. 1.7ohms at 4volts works out to 9.4 watts. 2.0ohm at 4.2volts which is 8.8 watts.

Of course, my Spinner may not be performing to what it is saying volt wise, so YMMV. I do know that on my non-vv mod, a fresh battery tastes and vapes a lot better and as the volts drop as the battery drains, the vape is less than ideal.

What set up are you using and what watts do you find best?

 

[junkman]

And i am not using sweet juices, and I have heard sweet juices burn at lower temps.......

 

[LucidAce]

I am using a DID clone on a Vision Spinner. My current coil started at about 1.7ohm and was vaping at about 4 volts, but the resistance is creeping up. I just checked and it is about 2.0 ohms now, which is why I suppose that I have been bumping the volts up a bit. 1.7ohms at 4volts works out to 9.4 watts. 2.0ohm at 4.2volts which is 8.8 watts.

Of course, my Spinner may not be performing to what it is saying volt wise, so YMMV. I do know that on my non-vv mod, a fresh battery tastes and vapes a lot better and as the volts drop as the battery drains, the vape is less than ideal.

What set up are you using and what watts do you find best?

And i am not using sweet juices, and I have heard sweet juices burn at lower temps.......

The fact that you're using a genesis atomizer also makes that higher wattage understandable. It's pretty common to run genesis atomizers at 10+ watts; I'm vaping somewhere in the 11-12 neighborhood right now with mine.

 

[Boden]

And i am not using sweet juices, and I have heard sweet juices burn at lower temps.......

That would explain it. I like my fruits.

 

[Boden]

I am using a DID clone on a Vision Spinner. My current coil started at about 1.7ohm and was vaping at about 4 volts, but the resistance is creeping up. I just checked and it is about 2.0 ohms now, which is why I suppose that I have been bumping the volts up a bit. 1.7ohms at 4volts works out to 9.4 watts. 2.0ohm at 4.2volts which is 8.8 watts.

Of course, my Spinner may not be performing to what it is saying volt wise, so YMMV. I do know that on my non-vv mod, a fresh battery tastes and vapes a lot better and as the volts drop as the battery drains, the vape is less than ideal.

What set up are you using and what watts do you find best?

I'm using a DuD on a Provari. Anything above 7.5W is blech. Tastes like burnt sugar.

 

[junkman]

Boden, could be that the provari is really providing the watts and my cheap spinner isn't? But I don't think so, cause I love the 1.7ohms on a fresh battery in a mechanical mod too.

Maybe just juice differences, mainly I vape a mix of 18-24mg french vanilla tobacco and kona creme from mad vapes.