Couple of questions about Battery Safety

[blabla]

Hello there! I have some noob questions i hope you can answer and help me with.

I have a Aspire NX75 mod, with Aspire ICR 18650 3.7V 20A Battery.

I checked in Mooch's post about how much Amps it put out(Aspire 20A 2500mAh ICR 18650 Bench Test Results...only a 15A battery). He puts the CDR at 15A.

Right now i have a rba with 0.5 Ohm coil and vape around 20-30W, this would mean i'm vaping around 7.7 - 8.9A, is this correct? Am i in a safe range? How far should i be from 15A?

Second question, the above is my vape when i'm out and about, at home i like to vape around 0.3ohm at 35-50W, for this i want a second device, i live in China right now, so not easy getting hold of genuine batteries.. so i'm gonna an internal battery mod, so either:

Innokin MVP4 100W(Maximum output Current: 35.5A, Maximum working Current: 30A)
or
Innokin Cool Fire IV 100W(Max working Current: 30A).

So my question is if i put a RDA on either of these with 0.3ohm coil and fire about 30-40w(Only 11.5A right?), i should be fine right? No need to worry about battery venting?

Sorry for the long post

 

[bombastinator]

Sounds right. Single battery mods should be fine in the 40 watt range it’s above 50w where you need to start doing math

 

[Rossum]

Right now i have a RBA with 0.5 Ohm coil and vape around 20-30W, this would mean i'm vaping around 7.7 - 8.9A, is this correct? Am i in a safe range? How far should i be from 15A?

Sounds right. How far you stay from 15A is a personal decision. A battery isn't going to vent if vaped at its CDR. CDR stands for Continuous Discharge Rating, meaning the battery can safely go from fully charged to fully discharged at that current, without any breaks to let it cool.

As for an internal battery mod, the mod itself should be designed in such a way that it limits the power output to levels that are safe for the battery that the mod's designers spec'd. I wouldn't worry much running a "100 watt" internal battery mod at 30-40 watts.

 

[stols001]

I think you should be fine also. If you want to update your batteries to more powerful ones, you can, but you don't have to. Hope you continue enjoying vaping and glad you are looking at safety issues. I'd say either Innokin should suit your purposes so go with the one you prefer.

Anna

 

[Walee]

Maybe you already know this but with a regulated mod there's a DC to DC converter which effectively isolates the load of the coil from the battery. You can calculate battery load simply using wattage applied and battery voltage. Example: 50W/4.2V=11.9A. If you want to be conservative for safety sake you can divide that answer by .85 which is about the lowest efficiency rating of a converter. For the above example that would yield 14A.

 

[VNeil]

Maybe you already know this but with a regulated mod there's a DC to DC converter which effectively isolates the load of the coil from the battery. You can calculate battery load simply using wattage applied and battery voltage. Example: 50W/4.2V=11.9A. If you want to be conservative for safety sake you can divide that answer by .85 which is about the lowest efficiency rating of a converter. For the above example that would yield 14A.

To be conservative/realistic you should divide by roughly 3.2V, not 4.2V (or whatever voltage you or your mod cuts off a discharged battery). In a regulated mod the amperage draw increases as the voltage drops over the charge cycle of the battery.

 

[Marc411]

Some easy reading, there are a couple real good one's on the wattage/voltage relationship in this batch of links.


Check out some of @Mooch's battery blogs for other cells (and their bench tests).
Mooch's Recommended Batteries | E-Cigarette Forum
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
18650 Battery Buying Guide for Vapor Users – Wake and Vape Blog
(9) Battery Basics for Mods; the Ultimate Battery Guide | E-Cigarette Forum
Calculating battery current draw for a regulated mod | E-Cigarette Forum
Battery Safety: Will You Marry Me? - Mt Baker Vapor
http://ecigarettereviewed.com/e-cig-charging-safety
Vaping 101: Battery Safety
Guide to Choosing a Battery Charger | E-Cigarette Forum
18650 Battery Buying Guide for Vapor Users – Wake and Vape Blog
Battery Basics for Mods; the Ultimate Battery Guide | E-Cigarette Forum
Calculating battery current draw for a regulated mod | E-Cigarette Forum
Battery Safety: Will You Marry Me? - Mt Baker Vapor
http://ecigarettereviewed.com/e-cig-charging-safety
Vaping 101: Battery Safety
Guide to Choosing a Battery Charger | E-Cigarette Forum
A Beginner's Guide to Your First Mechanical Mod
Explain it to the Dumb Noob: Ohm's Law Calculations
Battery Basics for Mods: The Definative Battery Guide for Vaping
Deeper Understanding of Mod Batteries Part 1
Are You Using a Rewrap (Rebranded) Battery?

Baditude's blog - Battery Basics for Mods; the Ultimate Battery Guide
Batteries, another Safety Guide - Published by IMFire3605's blog