Dual 18650 Series Battery Safety

[johnm1971]

I've always used an unregulated dual 18650 in parallel mod. Just recently, I aquired an unregulated dual 18650 in series mod (specifally a Tesla Invader 3). I've looked everywhere on here and can't quite find information on dual series battery safety. Can someone help me out here. I've got the Tesla Invader 3 and I'm using Samsung 25Rs. I would just like the formula for figuring out a safe coil build. I've been building single coils at around 0.6 or 0.7 ohms, and it seems to be a safe enough area and the batterys are staying cool. The Invader 3 does have variable voltage adjuster which goes from 3.7 to 6.6V. I believe my builds at 0.6 to 0.7 ohms are safe, but I would REALLY like to understand how to figure that out for sure. Please help!!!?

 

[champions]

Use vapecalc.com and input your build and your voltage.

Remember, in series only voltage will increase. You can still only pull 20 amps from your batteries safely.

At .6 you're only pulling 11amps, so vape on.

 

[johnm1971]

Use vapecalc.com and input your build and your voltage.

Remember, in series only voltage will increase. You can still only pull 20 amps from your batteries safely.

At .6 you're only pulling 11amps, so vape on.

Ok. Simple enough. I don't know why I was trying to make it more complicated than that, but I was. Thanks for the info!

 

[SteveS45]

Better safe than sorry will keep you off the evening news. No such thing as a stupid question they say!

Vape On Safely!

 

[johnm1971]

Better safe than sorry will keep you off the evening news. No such thing as a stupid question they say!

Vape On Safely!

True enough!

 

[sonicbomb]

On a dual battery mechanical:
Parallel - double the amp limit, so with the 25R this gives you 40 amps to work with.
Series - same amp limit, double the voltage eg. 8.4 volts fully charged.

Your mod has adjustable voltage capped at 6.6 volts

I = amps V = volts R = resistance P = watts

To find the amp draw use I=V/R
Eg. divide 6.6v by 0.6Ω = 11 amps (5.5 amps per cell)

To find the wattage use P=V²/R
Eg. 6.6v multiplied by 6.6v divided by 0.6Ω = 72.6 watts (not allowing for battery sag and voltage drop)

Or use steam-engine.

Assuming the same wattage is used, a series or parallel battery configuration will have the same total runtime.

 

[johnm1971]

On a dual battery mechanical:
Parallel - double the amp limit, so with the 25R this gives you 40 amps to work with.
Series - same amp limit, double the voltage eg. 8.4 volts fully charged.

Your mod has adjustable voltage capped at 6.6 volts

I = amps V = volts R = resistance P = watts

To find the amp draw use I=V/R
Eg. divide 6.6v by 0.6Ω = 11 amps (5.5 amps per cell)

To find the wattage use P=V²/R
Eg. 6.6v multiplied by 6.6v divided by 0.6Ω = 72.6 watts (not allowing for battery sag and voltage drop)

Or use steam-engine.

Assuming the same wattage is used, a series or parallel battery configuration will have the same total runtime.

 

[johnm1971]

On a dual battery mechanical:
Parallel - double the amp limit, so with the 25R this gives you 40 amps to work with.
Series - same amp limit, double the voltage eg. 8.4 volts fully charged.

Your mod has adjustable voltage capped at 6.6 volts

I = amps V = volts R = resistance P = watts

To find the amp draw use I=V/R
Eg. divide 6.6v by 0.6Ω = 11 amps (5.5 amps per cell)

To find the wattage use P=V²/R
Eg. 6.6v multiplied by 6.6v divided by 0.6Ω = 72.6 watts (not allowing for battery sag and voltage drop)

Or use steam-engine.

Assuming the same wattage is used, a series or parallel battery configuration will have the same total runtime.

Excellent. Thank you so much. I can vape without fear of blowing off my hand now! LOL That's exactly what I wanted to know with formulas and all. I wasn't sure how the voltage control would figure in, either.

 

[MMW]

Great choice on the box!
The Invader III is a regulated vv mod. Nothing about it is unregulated. It has safeties(low voltage, shorts, build limit of .1), voltage adjustment and a proprietary chip.

Go to steam engine under the Battery Drain tab. I have screenshots using your .6 build.

 

[johnm1971]

Great choice on the box!
The Invader III is a regulated vv mod. Nothing about it is unregulated. It has safeties(low voltage, shorts, build limit of .1), voltage adjustment and a proprietary chip.

Go to steam engine under the Battery Drain tab. I have screenshots using your .6 build.

Wow! That's great! I knew you guys could help me feel a little safer when vaping on this awesome mod! Thank you!!! I've never seen this section on Steam Engine, either, so thanks for that. Helps a lot!!!!

 

[MMW]

No problem brother!