How low can you go!

[aminul89]

Hi Guys n Gals

New to this. Im using a Stingray x Clone by Infinite (My first mech mod). Got an 18650 3.7V efest 2500mah and a discharge current of 20A. At the moment im running a 0.4ohm dual coil using 24G Kanthal. I wanted to know how low of a resistance can I go on that spec. Was thinking of building a 0.17 dual coil build using 22G Kanthal. Would that be safe?

 

[Susan~S]

Hello and welcome to the forum. Glad to have you here!

When considering how low you can build you need to give yourself some headroom. I try to never exceed 50% of the CDR (continuous discharge rating) of a fully charged battery (4.2v). So with a 20A battery, that would be 10A. This Ohm's Law Calculator tells me that a 0.4Ω build is as low as I would want to use.

The reason that I place a 50% limit is because as a battery ages the mAh of the battery degrades, as the mAh degrades so does the batteries c rating (amp limit). So down the road, a 20A battery may only be a 10A battery.

With a 30A battery (like the LG HB6), 0.28Ω is the lowest I would build.

Here are some of @Mooch's battery blog links I often post for others:

• There are no 18650 batteries with a genuine rating over 30A!
• Battery pulse ratings are useless!
• 18650 Safety Grades -- Picking a Safe Battery to Vape With
• Links to all his battery tests to date: List of My Battery Tests
• Calculating Battery Current Draw for a Regulated Mod

 

[suprtrkr]

I wouldn't go below about .5 on that battery. And I wouldn't use the "hybrid" adapter plate on that mod for all the tea in China. Welcome to the board.

 

[zoiDman]

Hi Guys n Gals

New to this. Im using a Stingray x Clone by Infinite (My first mech mod). Got an 18650 3.7V efest 2500mah and a discharge current of 20A. At the moment im running a 0.4ohm dual coil using 24G Kanthal. I wanted to know how low of a resistance can I go on that spec. Was thinking of building a 0.17 dual coil build using 22G Kanthal. Would that be safe?

Instead of asking How Low ohms can you go, shouldn't you be Asking yourself What is the Maximum Constant Amp Draw I can Safely ask my Battery to Provide? And if the Battery Fails, how much Venting does my Mod Have?

eFest Batteries are some of the most Cloned Batteries out there. And even Genuine eFest batteries have had Questionable Specifications.

 

[Susan~S]

I wouldn't go below about .5 on that battery.

@aminul89, Efest doesn't have a good reputation as far as re-wrap resellers. An open letter to Efest...you've gone too far

There are only a few battery manufacturers in the world who make their own "cells", including LG, Panasonic, Samsung, Sanyo, and Sony.

All the other brands on the market buy the second and third tier cells from those manufacturers and re-wrap them under their own brand. These are "second and/or third tier cells" which did not meet the higher standards of the original manufacturer. So, in order to compete with the original manufacturers' batteries (first tier), these other companies feel obligated to publish specifications which are inflated to make them appear superior to those of the original manufacturer.

* (AW is Andrew Wan, a former Panasonic employee who branched out to create his own "brand" of batteries. He allegedly has agreements with the major cell manufacturers to purchase first tier batteries from them. Not all batteries are created equal, so AW tests these batteries for quality. The best get chosen to be AW brand, and are re-wrapped as AW.)

Do your research before you buy. Decide what battery to buy depending upon the application that you will use them.

 

[KayP]

Hello and welcome to the forum. Glad to have you here!

When considering how low you can build you need to give yourself some headroom. I try to never exceed 50% of the CDR (continuous discharge rating) of a fully charged battery (4.2v). So with a 20A battery, that would be 10A. This Ohm's Law Calculator tells me that a 0.4Ω build is as low as I would want to use.

The reason that I place a 50% limit is because as a battery ages the mAh of the battery degrades, as the mAh degrades so does the batteries c rating (amp limit). So down the road, a 20A battery may only be a 10A battery.

With a 30A battery (like the LG HB6), 0.28Ω is the lowest I would build.

Here are some of @Mooch's battery blog links I often post for others:

• There are no 18650 batteries with a genuine rating over 30A!
• Battery pulse ratings are useless!
• 18650 Safety Grades -- Picking a Safe Battery to Vape With
• Links to all his battery tests to date: List of My Battery Tests
• Calculating Battery Current Draw for a Regulated Mod

Thank you very much. Very insightful.

 

[roxynoodle]

If you want to use a 0.17ohm build on a mech, please consider buying a dual battery, parallel mech like the Bigfoot mod by Cigreen. And still use quality batteries made by Sony, Samsung or LG that are 20-30A CDR.

 

[Bunnykiller]

.17 22ga. dual coils??? ummm not a good idea on a Stingray ( actually any single battery mech mod)... is your ohm meter really that accurate? and besides, thats alot of metal to heat up and cool down... by the time you get the coils hot enuf and vape, the coils will continue to cook the juice in the wick after you have let go of the button for several more seconds... if you are really interested in going with a build of that nature, consider looking into a dual battery regulated mod capable of 50+ W ...

 

[Bunnykiller]

just did some quick calcs.... that would be 100W at 25 A @ 4.2V
definately a battery stresser...

 

[sonicbomb]

As stated, if you want to make some big clouds a dual battery 100W(+) mod is a more effective and far safer way of achieving it.

 

[Two_Bears]

Hi Guys n Gals

New to this. Im using a Stingray x Clone by Infinite (My first mech mod). Got an 18650 3.7V efest 2500mah and a discharge current of 20A. At the moment im running a 0.4ohm dual coil using 24G Kanthal. I wanted to know how low of a resistance can I go on that spec. Was thinking of building a 0.17 dual coil build using 22G Kanthal. Would that be safe?

efest batteries are sketchy at best and dangerous at worst.

You need a good quality battery.

I HIGHLY recommend Samsung 25r, and LG HG2.

also I have heard good things about Sony batteries.

ECF has two battery experts @Mooch and @Baditude. Check out their posts and blogs. They will tell you all about batteries to use and avoid along with all of the battery safety you want to know.