Got a question for any battery geeks

[j21blackjack]

So, I've basically been a maintenance electrician in the navy for 12 years now, mainly maintaining machines and fairly simple troubleshooting. I have a very good working knowledge of electricity, but nothing very in-depth. So here's my question to the geeks;

I have a 1.25 ohm dual coil carto. I'll assume a brand new charged battery at 4.17V (that's what the AW IMR reads on the youtube video posted earlier), and 3.9V on my TF 3000mah. So, the AWs max output is almost 6 amps, that's hot! So I would be able to get max current with the AW at 3.3A (I=V/R), at 13.9W (P=IV). That's pretty ridiculous wattage.

On the other hand, using my TF, the only info I could find on it lists 1800mah (1.8A) working current. I know that max current is probably higher than the rated working current, but let's just assume 1.8A is max. So, the same 1.25ohm DCC would give me 3.12A at 3.9V which would be 12.1W of power. But, the amp limit is 1.8A, so therefore we only get effectively 2.25V (V=IR), and 4W of power.

Like I said, I'm no engineer, but these are the right equations. So it looks like I'm only vaping around 4-5 watts of power on my 1.25 ohm cartos. I'm actually afraid that if I were to buy and use an AW IMR, I wouldn't be able to use my 1.25ohm cartos anymore because they might blow up in my face or something. I certainly don't think they would be very useable considering how hard my cartos hit right now, even on my eGo's, which are only 3.2V!

 

[Sicarius]

Your TF's will give you around 2.5A so around 9W vaping

Edit : More specifically 2.5A average.

Check out the discharge curves for the 2400maH

http://lygte-info.dk/review/batteries2012/TrustFire TF18650 2400mAh (Flame) UK.html

PCB protection kicks in at 6.6A

 

[Creniker]

Your TF's will give you around 2.5A so around 9W vaping

Edit : More specifically 2.5A average.

Check out the discharge curves for the 2400maH

Test of TrustFire TF18650 2400mAh (Flame)

PCB protection kicks in at 6.6A

Ditto. The AW batteries work quite a bit better for high amp drain situations, and it shows through the performance. Thats why you get less voltage sag.

 

[jonny2hottie]

IMR's are a better choice overall. if your worried about the 12w result then just leave the 1.25ohm duals alone. 1.5ohm duals are plenty for 3.7v nominal batteries.

 

[DaveP]

An eGo outputs 3.4v. At that voltage, a dual coil carto at 1.5 ohms draws 2.2 amps and produces 7.7 watts. I get good vapes from my 1000mah eGo batt and a Madvapes 1.5 stainless steel dual coil. The battery doesn't complain or shut down. Those aren't recommended for my battery, but work for most people who post about using them.

I'd want the AW batts for anything less than 1.5 ohms. I mostly use the dual coils on a dual 14500 vv box mod and they work just fine.

 

[djej]

An eGo outputs 3.4v. At that voltage, a dual coil carto at 1.5 ohms draws 2.2 amps and produces 7.7 watts. I get good vapes from my 1000mah eGo batt and a Madvapes 1.5 stainless steel dual coil. The battery doesn't complain or shut down. Those aren't recommended for my battery, but work for most people who post about using them.

I'd want the AW batts for anything less than 1.5 ohms. I mostly use the dual coils on a dual 14500 vv box mod and they work just fine.

Dave, what batteries are you using on your vv mod? I was considering getting the madvapes vv box mod. In a variable volt situation (assuming the voltage with be maintained throughout the batteries life), do high drain batteries even make a difference, since you're controlling the voltage?

 

[Hoosier]

Dave, what batteries are you using on your vv mod? I was considering getting the madvapes vv box mod. In a variable volt situation (assuming the voltage with be maintained throughout the batteries life), do high drain batteries even make a difference, since you're controlling the voltage?

Yes, DC to DC converters have to conserve power, or they cannot change the power. So if voltage goes up, amperes has to go down and visa versa. So you cannot get the power out of the output (coil) unless you have the power at the input (battery).

 

[djej]

Yes, DC to DC converters have to conserve power, or they cannot change the power. So if voltage goes up, amperes has to go down and visa versa. So you cannot get the power out of the output (coil) unless you have the power at the input (battery).

Sorry for the ignorance, so you're saying high drain is a better choice for a vv mod?

 

[Sicarius]

Sorry for the ignorance, so you're saying high drain is a better choice for a vv mod?

Should be irrelevant.

If your battery is capable of 15W it is capable of 15W. The high drain batteries have a lower maH, but can supply a higher sustained current. Being able to supply 10A sustained is pointless unless you want to vape at 0.42 ohms (42w)

 

[Hoosier]

Should be irrelevant.

If your battery is capable of 15W it is capable of 15W. The high drain batteries have a lower maH, but can supply a higher sustained current. Being able to supply 10A sustained is pointless unless you want to vape at 0.42 ohms (42w)

Disagree as the vast majority of high mAh batteries I see are barely capable of 4 Watts without damaging themselves. So for 14W you're looking at a 2C rating and those are usually marketed as high drains.

The standards for these batteries suck. Labeling and marketing just keeps things more confused.

 

[Sicarius]

A 18650 that can't do 4W ?

 

[Sicarius]

Maybe I am spoilt for choice. The Samsung batteries I am using have a maxium discharge of 5200mA (20W at full charge). This is all thoretical, but I would like to check on the others I have. Possibly a drain test on a couple of brands is required.

 

[Hoosier]

Ah, I see where you're coming from now. That's not how I think of power output, yours is storage in my mind.

I'll take a testing of a 3000mAh battery I read about on the Candle Power forum recently as an example. Below 0.5 amp discharge it had a 2800mAh charge. At 0.5 amp discharge the tests averaged 1800mAh total charge. The protection circuit cut in at 1 amp. 3.7 volts at 1 amp is 3.7 Watt output to me as I don't care how much power is there if I cannot get it out.

 

[Sicarius]

Ah, I see where you're coming from now. That's not how I think of power output, yours is storage in my mind.

I'll take a testing of a 3000mAh battery I read about on the Candle Power forum recently as an example. Below 0.5 amp discharge it had a 2800mAh charge. At 0.5 amp discharge the tests averaged 1800mAh total charge. The protection circuit cut in at 1 amp. 3.7 volts at 1 amp is 3.7 Watt output to me as I don't care how much power is there if I cannot get it out.

Links to these discharge tests please ?

 

[Hoosier]

Links to these discharge tests please ?

This is the one I found when I went back to search for it. Ultrafire BRC3600 18650

I know there was another one, but I'm not finding it now. (I was doing a search for someone else's question when I found the one I remember and then saw this post.)

 

[Sicarius]

Some interesting reading there and the theory probably holds true. I can accept that in high current applications the mah rating can be degraded say from 2800mah to 2400mah, but that it purely due to a higher discharge rate. any higher differential and it is a clear indicator that the quality of manufacture is questionable. I am still interested in your statement of the protection circuit cutting in at 1 amp 3.7V. Do you mean a 1 amp discharge test and the battery protection operating when it reaches 3.7V ? That would make more sense, but again would indicate a terrible quality counterfeit. A run of the mill Li-ion from say DX can easily do 2.5A pulsed (ecig application - on/off/on/off/etc). At nominal 3.7V that's 9W of available power for vaping for the best part of the battery life.