Does this make sense?

[Smellybelly]

So I was reading about how to figure out the watt hours of a battery and it was pretty straight forward but got me thinking. If you can figure the watt hours (Wh) then you can figure how many hits per charge you can get from a battery before needing to recharge.

Bear with me as I am no math wiz and only passed high-school by cheating but if you know the watts your going to be vaping at, for example 55.5 and you know how long your average puff will be (3 sec hits from pressing fire to releasing fire). Then you will get an average of 240 three second hits from a 3000mAh rated bartery or 480 if it's a dual 18650 series battery at the same voltage.

My math goes as follows for a 3000 mAh 18650 or a brown lg.
Volts x Ah= Watt hours.
Example: 3.7x3=11.1
Meaning you could vape at 11.1 watts for a continuous hour
Then take how many watts your going to use (I tend to stay around 50w but for the sake of easy math I decided to use 55.5 in the example) and divide that by Watt hours.
So that looks like:
55.5/11.1=5 or 1/5 of an hour
Then divide 60 minutes by the answer from the previous equation to get the total minutes of vape time Our example is 5 so that would look like:
60/5=12.
Then multiply your total minutes of vape time by 60 to get your total seconds of vape time:
12x60=720 seconds of vape time.
Then divide your total seconds of vape time by how many seconds your average hit is from press fire button to release fire button to figure how many hits per charge you should get in perfect scenarios. I used 3 second hits for even numbers so:
720/3=240 total hits per charge.
If you have a box mod running multiple batteries in series then just multiply total hits per charge x number of batteries.

I am not saying this equation is correct I'm asking if it seems correct. The math seems right to me but a lot of things that are wrong seem right to me.

If there's any of you guys out there that actually know math would be able to see if this makes sense and seems right or if it's not point me into the right direction or if it can be simplified that would be great too.

 

[Tagi]

Not quite as involved as yours but take a look.

http://www.steam-engine.org/batt.asp

Edit - I have no clue about doing the calculation manually

 

[Sm0keydaBear]

The math is as simple as knowing the best amp rating for your battery and how many mAh it can do at that amount of amperage. This is how people would normally calculate how many puffs per battery they can obtain.

 

[Smellybelly]

So steam engines math is exactly the same as mine only there's one problem with mine. I didn't think about and factor in APV efficiency. Of course all you have to do is subtract the percentage that your device is from being 100% efficient. So If I was to say my device is 90% efficient, then I would take 144 (steam engine doesn't allow you to change puff length so we have to do with 5 sec. puffs) and subtract 10% for a total of 129.6.

@Sm0keydaBear
Could you show me an example of that. Say a lg hg2. So that's a battery rated at 20 amps and 3000 mAh so do you mean at full continuous 20 amps this would mean that it could run for 9-ish minutes. If that's what your saying it's the same math just not the conversion to turn amps into watts at the beginning. And then of course you have to factor in your APV efficiency.

 

[93gc40]

I am glad there are still people out there capable and willing to do the math..

You can only get close to your target answer, with all the math it's still an approximation. Many of the factors are variable. SteamE uses 5 second average puff length, I bet you couldn't take 3 puffs in row of the same length or pressure, without a timer or pressure gauge. Actual battery strength will be different with every use and puff. Steam only accounts for mod efficiency, because I don't think we can really account for efficiency of the build or battery or the puff itself.

I don't count my puffs, heck I can't remember the count long enough to count puffs per Drip, much less worry about puffs per battery. I just go by, demonstrated, hours on the clock per battery or bottle. Which while being wildly variable.. Is close enough to tell me how much juice and how many batteries, I need to carry. And rarely requires more than simple kindergarten math.

 

[Smellybelly]

Oh of course. I mean I really rarely even take three second hits. I more or less stick to 1 or 2 second puffs. And it's so variable because like you said who's actually cpunting. Plus then you have to factor in ambient temperature. My Florida summers are going to make the battery not last as long as someone's Michigan winters. Then you have the coils as you said. And I like to mess around with the watts. So I never stay at 50 watts. But it is kinda cool to be able to figure out how many minutes you can get from a battery. A bettery will last me almost a full day at 50ish watts and yet really it's only supplying me with 12 total minutes of vape time which kinda puts it into a weird perspective. I spend a little over 12 minutes a day breathing in vapor.

 

[Sm0keydaBear]

So steam engines math is exactly the same as mine only there's one problem with mine. I didn't think about and factor in APV efficiency. Of course all you have to do is subtract the percentage that your device is from being 100% efficient. So If I was to say my device is 90% efficient, then I would take 144 (steam engine doesn't allow you to change puff length so we have to do with 5 sec. puffs) and subtract 10% for a total of 129.6.

@Sm0keydaBear
Could you show me an example of that. Say a lg hg2. So that's a battery rated at 20 amps and 3000 mAh so do you mean at full continuous 20 amps this would mean that it could run for 9-ish minutes. If that's what your saying it's the same math just not the conversion to turn amps into watts at the beginning. And then of course you have to factor in your APV efficiency.

The mAh rating goes down usually when a battery passes 10A. The usual mAh (I think, I don't know this for sure) is 1-10A and is where they get the mAh rating. Once you go above that, the mAh goes down.

 

[edyle]

So I was reading about how to figure out the watt hours of a battery and it was pretty straight forward but got me thinking. If you can figure the watt hours (Wh) then you can figure how many hits per charge you can get from a battery before needing to recharge.

Yes you can.

And if you know the specific latent heat of vaporization of your liquid (using the value for water is close enough) you can estimate how many millilitres 1 battery can vape.