Maximising battery life on my single 18650/smaller devices.

[conanthewarrior]

Hi everyone, I hope you are all doing OK.

I have a question regarding my small, single 18650 powered devices. I recently added a Pico to the collection, and a Tesla Nano (Li-Po-but I still want to maximise battery).

On the Pico, I am using a goblin mini V2, with a single, 2MM ID 26G 0.92 Ohm coil. I understand resistance does not really matter, but thought I would add it so you knew what I was using.

I use this at around 17.5W, and vapour production is good, and I like it. I also get pretty good battery life for a single 18650 device.

However, on my Tesla Nano, I am using a Diablo 2 tank, with dual 2MM ID coils, that needs around 32W to work well. I find this does not last the day, and understand this is due to using nearly double the watts.

I have another Goblin mini, and am thinking of also using that on the device in a single coil setup, or a billow Nano.

For longest possible battery life though, would I be best for going for a single, lower resistance coil, as I understand bucking is more efficient than boosting, or is the difference pretty negligible, and 0.9-1Ohm will be a good place to go to maximise battery life from my smaller devices, while still providing enough vapour/throat hit for my needs?

I use either 25R's, 30q's, HE4's or HG2's. I can't say I have actually noticed a real difference myself with the 3000MAH cells in single 18650 configuration, although set up in one of my Dual 18650 mods, there is a noticeable difference in battery life.

I do not know if this is due to the way the higher capacity batteries work, or I am getting a benefit but it is small so am not noticing.

Thanks everyone, Conan.

 

[Izan]

Single coils, medium resistance (1-2Ω), lower airflow and triple your nic level.
What you VISIBLY exhale...is wasted: nicotine, battery life, dilutant.
Stealth (double inhale) until you exhale little or nothing.

Cheers
I

 

[K_Tech]

It's all about the power. In a regulated mod, think of the battery as a container that holds amps. Regardless of the resistance of the atomizer, the regulating circuit will pull the amount of amps required from the battery in order to provide the voltage needed to the atomizer in order to generate the wattage you're asking for.

Using an 18650's nominal voltage of 3.7 volts:

At 10 watts, the board will be pulling 2.7 amps from the battery.

At 30 watts, the board will be pulling 8.1 amps from the battery.

That being said, you'll want to target a setup that will provide the best performance at lower wattage, which is (generally) a build with thinner gauge wire. Although a 1 ohm build with 27 gauge wire and 30 gauge wire are mathematically the "same", the 27 gauge build will require more power to generate enough heat in the wire because of its thickness, although coil configuration, atomizer design, and air flow also play VERY important roles.

 

[sofarsogood]

Hi everyone, I hope you are all doing OK.

I have a question regarding my small, single 18650 powered devices. I recently added a Pico to the collection, and a Tesla Nano (Li-Po-but I still want to maximise battery).

On the Pico, I am using a goblin mini V2, with a single, 2MM ID 26G 0.92 Ohm coil. I understand resistance does not really matter, but thought I would add it so you knew what I was using.

I use this at around 17.5W, and vapour production is good, and I like it. I also get pretty good battery life for a single 18650 device.

However, on my Tesla Nano, I am using a Diablo 2 tank, with dual 2MM ID coils, that needs around 32W to work well. I find this does not last the day, and understand this is due to using nearly double the watts.

I have another Goblin mini, and am thinking of also using that on the device in a single coil setup, or a billow Nano.

For longest possible battery life though, would I be best for going for a single, lower resistance coil, as I understand bucking is more efficient than boosting, or is the difference pretty negligible, and 0.9-1Ohm will be a good place to go to maximise battery life from my smaller devices, while still providing enough vapour/throat hit for my needs?

I use either 25R's, 30q's, HE4's or HG2's. I can't say I have actually noticed a real difference myself with the 3000MAH cells in single 18650 configuration, although set up in one of my Dual 18650 mods, there is a noticeable difference in battery life.

I do not know if this is due to the way the higher capacity batteries work, or I am getting a benefit but it is small so am not noticing.

Thanks everyone, Conan.

ohm's do matter. A higher ohm coil converts power into heat more efficiently. If you used a thick copper wire for a coil it would pass the power through the coil and produce very little heat because resistance would be very low. Low ohm coils need more power to produce a given amouth of heat. I want an LG HG2 make it through a full day. The setup described in the signigure below vaporizes 7 ml of liquid during a full day. That is about 17-20 minutes of firing time. Double the watts and firing time decreases by half.

 

[conanthewarrior]

ohm's do matter. A higher ohm coil converts power into heat more efficiently. If you used a thick copper wire for a coil it would pass the power through the coil and produce very little heat because resistance would be very low. Low ohm coils need more power to produce a given amouth of heat. I want an LG HG2 make it through a full day. The setup described in the signigure below vaporizes 7 ml of liquid during a full day. That is about 17-20 minutes of firing time. Double the watts and firing time decreases by half.

Sorry-I meant in the way it affects the device/how it works-not the thickness of the wire, I understand a thick, lower gauge wire will have more ramp up time than a thinner, high resistance coil.

I should've made myself more clear there-I did make a thread a while back about does resistance matter on a regulated mod, and it was explained to me how to calculate amp draw correctly on my regulated mods.

I will dig out some of my thinner wire, and get building something, ideally single coil, that can be used at a low wattage.

The build suggested by @sofarsogood sounds good for me, I don't have any SS in 28 gauge though, but I do kanthal, so shall give it a try .

Thank you all for your help, hopefully I will get a decent vape at a low power level, which will last the day for me.

 

[sparkky1]

ohm's do matter. A higher ohm coil converts power into heat more efficiently. If you used a thick copper wire for a coil it would pass the power through the coil and produce very little heat because resistance would be very low. Low ohm coils need more power to produce a given amouth of heat. I want an LG HG2 make it through a full day. The setup described in the signigure below vaporizes 7 ml of liquid during a full day. That is about 17-20 minutes of firing time. Double the watts and firing time decreases by half.

A higher ohm coil will take longer to heat and produce a cooler vape ( maybe that's your idea of more efficient ? ), requiring a longer pull than a lower ohm @ the same watts applied to get the same amount of vapor.
Heat flux is what i'm referring to.
Coil wrapping

 

[vapo jam]

A higher ohm coil will take longer to heat and produce a cooler vape

Only if you're using the same gauge wire. A 22 AWG, 0.4 ohm coil will take twice as long to heat up as a 22 AWG, 0.2 ohm coil because there's twice as much wire. A 32 AWG, 2 ohm coil will heat up much more quickly than either one, though, because there's much less mass to heat.

 

[sparkky1]

Only if you're using the same gauge wire. A 22 AWG, 0.4 ohm coil will take twice as long to heat up as a 22 AWG, 0.2 ohm coil because there's twice as much wire. A 32 AWG, 2 ohm coil will heat up much more quickly than either one, though, because there's much less mass to heat.

The example was of "single coil, 28 gauge stainless wire, 1.36 ohm" having to do with the heat flux, I think the OP understands how wire gauge works ................

 

[evan le'garde]

Just my tuppence worth.

I'm using my Provari v2.5 combined with my Kayfun V4. Tried various different gauges. Eventually i settled on 32g, 5 wraps, 1mm id, 1.7ohm at 3.7 volts. As optimized as i can make it.

And if it didn't provide enough vapour i wouldn't be using it, nor would i be at 3.7v.

 

[Munk]

I'm waiting on my cotton so I haven't tried it yet, but here is a micro coil on a Goblin Nano (same deck as the Goblin Mini). Stainless steel, 28 gauge, 1/16" inner diameter, 15 wraps, ~1.15 ohms. I was trying to do the same thing as you, balance efficiency and vapor production on a single 18650 device.

Here's what I would suggest -- use the steam engine battery calculator and plug in your battery info. For example, with an HG2 battery / 0.9 ohm coil / 17.5 watts, it's saying that you'll get 411 puffs. By dropping the power to 15 watts but keeping everything else the same, you get 480 puffs. That in itself is a pretty big gain for a small change in power. To compensate for vapor loss, you can increase the resistance of your coils by either using a thinner gauge wire (maybe 30 or 32) and/or by adding wraps to your coil.

That being said, I say you wrap a ~1.5 - 2 ohm coil, and start with your watts set very low (7 maybe). Making sure to keep your hit time consistent, say 3 second long puffs, increase the watts by .5 increments until you get just enough vapor to fill your needs. After all, a 6 second hit with lower watts may have more battery drain than 3 second hit with slightly higher watts.

 

[sofarsogood]

Only if you're using the same gauge wire. A 22 AWG, 0.4 ohm coil will take twice as long to heat up as a 22 AWG, 0.2 ohm coil because there's twice as much wire. A 32 AWG, 2 ohm coil will heat up much more quickly than either one, though, because there's much less mass to heat.

I use temp control. Are the rules a bit different? In that situation the mod hammers the coil with the max watts you specify until the wire reaches a predicted temperature. If things are working as they should the entire surface area of the wire is radiating the set temperature assuming the max watts are high enough to reach that temp when it's being cooled by vapor production. My understanding is a low ohm coil needs more power to produce a given amount of heat because more of the power is passing through the coil without producing heat.

My goal with vaping is to get a good throat hit and a modest amount of quality vapor. I want that as conveniently as possible. The set up in the signiture below is the best I've come up with so far.

 

[vapo jam]

I use temp control. Are the rules a bit different?

The rules are exactly the same, assuming the same material. If you were to keep all settings the same while using a 24 AWG SS wire (same number of wraps, lower resistance), it would take noticeably longer for the temperature to ramp up. If you used 32 AWG instead, it would hit temperature almost instantly.

One (very over-simplified) way to think of it is to imagine heating water. If you put a few drops of water in a pot and put it on the stove, the water will boil very quickly. If you fill the pot, though, it will take quite a bit longer and quite a bit more energy to bring it to a boil because you need to heat up significantly more mass.

Similarly, with larger wire (and especially with high-mass Clapton/etc. coil builds), there's literally more wire that you need to heat up before it reaches temperature.

 

[sofarsogood]

The rules are exactly the same, assuming the same material. If you were to keep all settings the same while using a 24 AWG SS wire (same number of wraps, lower resistance), it would take noticeably longer for the temperature to ramp up. If you used 32 AWG instead, it would hit temperature almost instantly.

One (very over-simplified) way to think of it is to imagine heating water. If you put a few drops of water in a pot and put it on the stove, the water will boil very quickly. If you fill the pot, though, it will take quite a bit longer and quite a bit more energy to bring it to a boil because you need to heat up significantly more mass.

Similarly, with larger wire (and especially with high-mass Clapton/etc. coil builds), there's literally more wire that you need to heat up before it reaches temperature.

I can make the big pot of water reach a boiling point just as fast as the small pot by hitting the large pot with more heat--until it reaches the boiling point. That's what temp control does. If the max watts are high enough the fat wire heats up as fast as the thin wire, for practical purposes but the moment the set temp is reached power is reduced so the wire doesn't exceed the set temp. But if the fat wire is lower ohms than the thin wire more of the power will bass through the wire without creating heat. It appears that's why low ohm coils need higher watts, they are less efficient at producing heat.

 

[vapo jam]

I can make the big pot of water reach a boiling point just as fast as the small pot by hitting the large pot with more heat--until it reaches the boiling point. That's what temp control does. If the max watts are high enough the fat wire heats up as fast as the thin wire, for practical purposes but the moment the set temp is reached power is reduced so the wire doesn't exceed the set temp. But if the fat wire is lower ohms than the thin wire more of the power will bass through the wire without creating heat. It appears that's why low ohm coils need higher watts, they are less efficient at producing heat.

Exactly - more heat (ie, more energy). In the context of the original post, you'd conserve battery by using thinner wire/higher resistance and using less energy to heat to the desired temperature.

 

[sofarsogood]

Exactly - more heat (ie, more energy). In the context of the original post, you'd conserve battery by using thinner wire/higher resistance and using less energy to heat to the desired temperature.

It appears we agree. The original post asks how to conserve battery power. So here's how I answer for myself. I care about battery endurance. Ideally the mod I'm carrying will last me a full day with no recharging and no swapping batteries. The vtc mini tells me I vape 1000-1200 seconds a day of firing time at 400 degrees and 30 max watts through a 1.2-1.3 ohm coil. I also go through about 7 ml per day. The battery drain section of the steam engine calculator says an LG HG2 will fire at 30 watts for 20 minutes, 1200 seconds. If I could reduce that to 15 watts I would get 40 minutes of firing time. 20 minutes is enough. If I was using a much lower ohm coil I'd need more power to vaporize 7 ml of liquid so the LG HG2 wouldn't last the whole day. (When I watch the watts display in a mirror during a puff the watts go to 30 for a fraction of a second then drop significantly below that for may be half the puff time so I should do a little better than 1200 seconds.)

What happens in practice is my mod is charging most of the time and I'm vaping on passthrough because I have chargers at home, in the car and at work. Out and about on the motorcycle or on field trips I usually carry a spare battery just in case I get stranded some where. On overnight trips I carry a spare mod and spare rda with a dry wick.

 

[conanthewarrior]

It appears we agree. The original post asks how to conserve battery power. So here's how I answer for myself. I care about battery endurance. Ideally the mod I'm carrying will last me a full day with no recharging and no swapping batteries. The vtc mini tells me I vape 1000-1200 seconds a day of firing time at 400 degrees and 30 max watts through a 1.2-1.3 ohm coil. I also go through about 7 ml per day. The battery drain section of the steam engine calculator says an LG HG2 will fire at 30 watts for 20 minutes, 1200 seconds. If I could reduce that to 15 watts I would get 40 minutes of firing time. 20 minutes is enough. If I was using a much lower ohm coil I'd need more power to vaporize 7 ml of liquid so the LG HG2 wouldn't last the whole day. (When I watch the watts display in a mirror during a puff the watts go to 30 for a fraction of a second then drop significantly below that for may be half the puff time so I should do a little better than 1200 seconds.)

What happens in practice is my mod is charging most of the time and I'm vaping on passthrough because I have chargers at home, in the car and at work. Out and about on the motorcycle or on field trips I usually carry a spare battery just in case I get stranded some where. On overnight trips I carry a spare mod and spare rda with a dry wick.

Hi @sofarsogood-I notice that you mention the Evic VTC mini can tell you how many seconds you are actually vaping for per day.

I have no idea how many seconds I actually use any of my devices for, but I do own the Evic VTC Mini. How do I get up the second counter onto the display?

I am not too sure where the instructions are if I am honest, I have looked in my ottoman, but there is a lot of boxes and various vaping related items in there, it would be handy to know a rough estimate of how long I am actually vaping for per day, on a build suited for maximising battery life (I run many different tanks and RDA's with different builds on different mods, but when it comes to my single 18650 powered mods, I do try to stick to something similar to get the best I can from them).

Thanks, and all the best, Conan.

 

[rice721]

short answer, thinner wires, single coil if the option exists with higher resistance and vape it at the lowest possible wattage (or TC) that you find suitable.

 

[GeorgeS]

Thinner wire has less mass. The less mass will heat/cool faster. The downside is the lack of mass in the coil needs to be adjusted with the ID of your coil and wick. (reduce the mass of your wick)

A single 1.5-2.5MM ID coil made of 28-32AWG with a target resistance greater than 0.5 ohm and less than 1-1.5 ohms (while many of the modern Joytech TC devices will fire a coil in TC mode up to 1.5 ohms, many older devices won't fire anything greater than 1.0 ohm in TC mode)

 

[Foggy Road]

short answer, thinner wires, single coil if the option exists with higher resistance and vape it at the lowest possible wattage (or TC) that you find suitable.

Add NR-R-NR wire to this and you get the exact recipe that gets me 12-14 hours from my Ego/Evod 650mah VVs and 700mah 18350s.

 

[tj99959]

A higher ohm coil will take longer to heat and produce a cooler vape ( maybe that's your idea of more efficient ? ), requiring a longer pull than a lower ohm @ the same watts applied to get the same amount of vapor.
Heat flux is what i'm referring to.
Coil wrapping

That's only true if you use the same gauge wire.
Wrap that same higher resistance with say 36 gauge wire and it will probably heat up faster than you can control.

Also ohms law is a circle, and no one factor is more important than the other three. If you change one factor ... you will change all 4.

However amperage draw is the ONLY factor that determines how long a battery charge lasts.
At 2 amps a 18650 will easily last all day. At 20 amps you will reduce that time by a magnitude of 10. If you want more watts, it comes at the price of more amps.