I just became a safety hypocrite

[yinsen]

im always the one banging on to my recruited vape friends about battery safety, and I just realised i've been consistently vaping an 0.5ohm dual coil on AW 18490s for like a fortnight.

so I'm asking some veterans to educate someone who just proved himself a dunce and tell me:
do I need to dispose of the batteries immediately - and also, could you please run me through the calculations of determining safe lower limit ohmage based on amps?

thankyou!

 

[yinsen]

if it's relevant, they still peak at 4.18v and seem to discharge at the same rate as ever

 

[Rickajho]

Semantics first:

Was that a dual coil build metering at 0.5 ohms? Or dual 0.5 ohm coils?

 

[slappy3139]

AW 18490s are rated for 16 amps I believe, so you should be fine with a .5 ohm build.

 

[yinsen]

1 ohm per coil, with 0.5ohm final resistance for both running together

 

[Cullin Kin]

The AW 18490's have a rating of 8C and 1100mah (1.1Ah), which is 1100mah=1.1Ah*8C=8.8A continuous discharge.

This would mean you could max out your battery at V=IR --> R=V/I=4.2V/8.8A=0.4772727Ω or 0.48Ω.

So, it looks as though you were within the continuous discharge limit, but definitely right at the edge.

If it were me, I would stay above 0.6Ω. At 0.6Ω you are using 7A which is 80% of the max continuous discharge and should be safe. At 0.5Ω, you were drawing V=IR --> I=V/R=4.2V/0.5Ω=8.4A which is 95% of the max continuous discharge.

Thanks for taking the time to practice what you preach, it's good to see that.

Edit: Is yours rated at 8C or 15C? If it's 15C then Your continuous discharge would actually be 16.5A and you would be well within the safe zone. All of the ones I'm seeing that are sold at vape shops are 8C, so I believe what I posted above is still valid.

 

[Rickajho]

1 ohm per coil, with 0.5ohm final resistance for both running together

Didn't mean to be picking of you, but that's a point of distinction lost on a lot of people who build coils 'via calculator' and don't understand the consequences of a parallel coil build.

Cullin Kin covered the math good . If you managed to keep from draining them below 2.5 volts you should be fine.

 

[danaway]

Perhaps a dumb question, but are all aw 18490s rated to 16.5A continuous? If not how can you tell?

 

[Ian444]

Plus, a continuous rating means holding the fire button down until the battery is exhausted, ain't going to happen on a PV. Not that you can factor that in, but it does add a safety margin of some sort.

 

[Ian444]

Good question danaway, everyone quotes specs from somewhere, but a reliable source to answer that question is something I haven't seen (yet).

 

[Rule62]

According to the RTD website, the 18490s are 15C
AW IMR 18490 3.7v 1100mAh - RTD vapor

 

[want to quit]

That's too borderline for me.

1 ohm per coil, with 0.5ohm final resistance for both running together

 

[Funk Dracula]

You're fine with .5Ω on an AW18490. Terrible runtime, but you're fine.

 

[yinsen]

Didn't mean to be picking of you, but that's a point of distinction lost on a lot of people who build coils 'via calculator' and don't understand the consequences of a parallel coil build.

Cullin Kin covered the math good . If you managed to keep from draining them below 2.5 volts you should be fine.

no problem! i was unclear. i use an ohm meter and check my batteries regularly, lowest ive ever taken them was 3.6v.

Perhaps a dumb question, but are all aw 18490s rated to 16.5A continuous? If not how can you tell?

beat me to it. i'm having a hard time finding concrete documentation about this - it's not stated on the battery itself. imr 186490, 3.7v, 1100mAh (4.1WH)

 

[Filthy-Beast]

The real question is, are they genuine AW IMR 18490 1100 mah batteries? where did you get them?

 

[yinsen]

they're absolutely genuine, i bought them from provape when i had a provari and only started using them recently in my nemesis as i started getting into dripping.

 

[eratikmind]

im always the one banging on to my recruited vape friends about battery safety, and I just realised i've been consistently vaping an 0.5ohm dual coil on AW 18490s for like a fortnight.

so I'm asking some veterans to educate someone who just proved himself a dunce and tell me:
do I need to dispose of the batteries immediately - and also, could you please run me through the calculations of determining safe lower limit ohmage based on amps?

thankyou!

An AW IMR 1100 mAH 18490 battery has a 15C rating.

Which is (1100 / 1000) 15 = 16.5 amps.

As such, you have nearly a 50% cushion.

 

[eratikmind]

they're absolutely genuine, i bought them from provape when i had a provari and only started using them recently in my nemesis as i started getting into dripping.

Likewise, I used to use the 490s in my Nemies and GP Paps.

Just be sure to monitor the remaining voltage available in the battery. I typically change my batteries at some 3.6/3.7ish volts. You don't want to over drain them.

 

[Cullin Kin]

There are both 8C and 15C AW 18490's. It's up to you to know which you have. It should say on the battery.

Here are a bunch of links to 8C AW18490's

http://www.empiremods.com:80/product_p/imr18490.htm=]AW IMR 18490 Battery[/url]

AW 18490 IMR 1100mAh Button Top

AW IMR 18490 - Kidney Puncher

Vapor Store Seattle, Tacoma WA | E-cigarettes Lakewood, Fife

Point being, it's not automatic that you have the 15C.

 

[danaway]

Yep some extra attention is required with the 18490s, but same story, you can tell when the voltage is fading. I never over drain my batts because I hate vaping on lower volts.. Mine are are from reputable resellers, I have no doubt they're genuine AW 18490s but an earlier post had me worried that not all AW 18490s are rated to 16.5A.