Volts, Amps, Ohms, Battery Life Oh my!

[Sev00]

Hi All,



Well there are a lot of good post explaining Volts, Amps, Ohms and Battery Life. But I will add a new revelation at the end. So here just a quick refresher.


Wattage – P, Volts – V, Ohms – R, Amps – I


(volts * volts) / Ohms = watts [or P = IV]
volts / ohms = Amps [or V / R = I]
.
-> don't hurt your brain, download an ohm's Law calculator. PC, MAC or smart phone. Many free to choose from.


Watts is the measure of power used, so therefore the measure of power taken from your batterie(s). And given a certain power usage the resulting vape will be pretty constant no matter how you juggle the values to reach the same watts. This is why the Darwin is so popular albeit out of reach for most of us. Also if you ever bought a hair dryer or microwave, you compared models on wattage.



So the new part, what extends battery life more?



Do I choose low volts and low ohms (res) to reach say 10 watts?

Do I choose high volts and high ohms (res) to reach the same 10 watts?



The answer is either will work and since its the same wattage, it will drain the battery at the same rate. So which should I choose? Well high volts and high ohms produce less amps. Now in an ecig mod built with proper size and length wire, good solder points you most likely will not get into bleeding off heat and wattage. (This is why stoves, ovens and clothes dryers are 220AC, not 110AC). But a lower amp load on your batteries is kinder. Running batteries at or near their amp limit will shorten their life fractionally. Its not a big impact, but I am all about saving the green (both ways, dollars and the earth). So if you can push less amps and get some extra charge cycles out of that battery, Its good.

I hope this helps someone. Knowledge is power!

Sev

 

[chillidc]

Nice post. In term of LR v SR and battery life its also important to remember that it also reduce battery running time as well as overall battery life. A VV device running 10Watts with a 3Ω cart (1000mah battery) will outperform a standard device running a 1.5Ω cart at 10 watts (1000mah battery).

 

[NornSaber]

Great Posts !!!

shouts going out to Sev00 and chillidc

 

[rayvus]

great post good refresher for me.

 

[Ratchet]

Totally beyond me... LOL! My brain won't function that well on a Saturday morning. I don't calculate Watts, volts, ohms, and whatever else, I'm just enjoying the vape..............

 

[tj99959]

Then of course there is how is all that power managed. Is your PV pulse regulated, a VV or VW APV, regulated or boosted? How many coils in your atty/carto? There are more ways to pluck this chicken and get the same result than you can count. There are also more ways to pluck this chicken to change the result than you can count.

 

[PittBoss]

Totally beyond me... LOL! My brain won't function that well on a Saturday morning. I don't calculate Watts, volts, ohms, and whatever else, I'm just enjoying the vape..............

Once you get into VV (if you decide to) Ohms law, etc. become second nature. But I also concur that sometimes, who cares what I'm pushing, as long as I am enjoying it!

 

[Sev00]

Then of course there is how is all that power managed. Is your PV pulse regulated, a VV or VW APV, regulated or boosted? How many coils in your atty/carto? There are more ways to pluck this chicken and get the same result than you can count.

That is very very true.

linear regulator = 70% efficient
switching "buck" = 90% efficient
switching "boost" = 90% efficient
PWM = 97+ efficient

You pay a little more each step up, but worth it for the most part. I personally like the buck for performance, price point and ease of mod build. But will venture into PWM after I study up a little more.

Sev

 

[sailorman]

Another factor to consider is that a higher ohm/higher voltage combination results in smaller changes to watts as the voltage is incremented up and down. That plays a part in VV APVs where finer "tuning" of the wattage is desired.

 

[cigarbabe]

Not to denigrate the necessity of understanding "Ohms Law" for most vapers but I simply prefer to wrap a coil forget totally about ohms/watts and just vape.
It's why I love my Zenesis mods!
C.B.

 

[Ratchet]

Once you get into VV (if you decide to) Ohms law, etc. become second nature. But I also concur that sometimes, who cares what I'm pushing, as long as I am enjoying it!

Already there, using a Lavatube but still, I don't worry about the ohms, watts, and whatever. I play with the voltage and mainly use single coil 3.0 cartos but I don't even attempt to figure out how many watts I'm vaping at.... LOL!

 

[AttyPops]

Yeah, but the LT is using buck/boost. He's not even going there (Yet).. well, he kinda did in post #8...90%???. It draws extra amps to boost voltage. So HV may stress the battery further using the amps = stress point in post #1. Those mods using two batteries (PROTECTED!) will benefit greatly from a switching regulator for efficiency (said/typed while vaping my 5v linear regulator APV ).

The main point for vv is that you like the vape. The design specs come into play while constructing mods. That said, it is rather pointless to use LR stuff on a VV device, but can be done if you only have LR stuff due to a standard big-bat non-vv e-cig.

 

[Sev00]

I got the banner, yahoo!

 

[Sev00]

Not to denigrate the necessity of understanding "Ohms Law" for most vapers but I simply prefer to wrap a coil forget totally about ohms/watts and just vape.
It's why I love my Zenesis mods!
C.B.

Cool stoggie mod. I like your avatar.

 

[Sev00]

Yeah, but the LT is using buck/boost. He's not even going there (Yet).. well, he kinda did in post #8...90%???. It draws extra amps to boost voltage. So HV may stress the battery further using the amps = stress point in post #1. Those mods using two batteries (PROTECTED!) will benefit greatly from a switching regulator for efficiency (said/typed while vaping my 5v linear regulator APV ).

The main point for vv is that you like the vape. The design specs come into play while constructing mods. That said, it is rather pointless to use LR stuff on a VV device, but can be done if you only have LR stuff due to a standard big-bat non-vv e-cig.

I totally agree. This was on my mind because I just built my 1st battery mod. It uses 2 18650 in serial with a linear regulator (I know, the next one will be a switching "buck". So I guess this is really kinda geared towards the two battery mod builds. Or a production two battery for that matter.

What I have found since I started using my vv, is I pretty much set it and forget it. But last week, my local vendor (DFWVapor) was out of my prefered res cartos. I had to get through the weekend, so bought what they had. With this knowledge it was easy to quickly home in on the right vv setting for myself.

One other point on understanding a little of this. Say I put a 1.5 ohm carto on my vv, then set the volts to 5.5. I would be drawing 3.667 amps. Unless I had a production mod with safety, like the Lavatube, I would kick the protection circuit on my battieries. Or worst case smoke my momentary switch. If I am not near my re-charger to reset the PCB on the batteries or have spare parts, I am vaperless. I know, I know, always carry a backup. Just saying though. Better too much knowledge than not enough.

Sev