True 200 watts? How is voltage measured?

[Arvidx]

It's strange...  I had a rather long discussion with one of the other dna200 owners here in town and we were discussing 'true 200 watts' as far as 2 battery mods.  I have been of the impression that 2 cell regulated mods were essentially incapable of keeping up a 200 watt output for any length of time.  He did a basic voltage test at the atomizer and confirmed that an IPV3li was outputting less than the claimed voltage on the RDA.  However as a followup, he also did the test, same RDA with the DNA200 and received nearly the same result.   Here's a copy of the post. 

I did a comparison test with my dna 200 and the ipv3li. Atty was .124 ohms, and with the dna 200 floored it was allegedly at 4.98 volts internally for an alleged 40.21 Amps and 200.1 watts. I measured on my multimeter at the atty posts simultaneously, and saw 4.63 volts there.

On my IPV3Li with a fresh set of HE4's (maybe 15 cycles on this set) the screen reads .12 (same build/atty ofc) and it calculates 4.89V . Upon firing it I see a steady 4.62V at the atty terminals. If we are to assume a similar power loss to the DNA200 atty connector/internals, and assume that the dna 200 has accurate internal measurements, then it would appear as though the IPV3li measures up pretty closely. You might even argue that the IPV3li is losing less power because it is anticipating needing to put out 4.89v vs 4.98 (from the more sensitive resistance measurement of the dna 200 chiming in at .124) yet only shows a difference of 1/100th of a volt at the end of the line. 

I forgot about the battery sag test and redripped 2x before realizing, which I would estimate at over 12 hits, although probably < 2 seconds per drag as it's rather toasty. I'm still seeing the same 4.62 at the atty screws after vaping this much.

I suppose it comes down to semantics regarding being ok with an internal reading of 200W being supplied versus a reading at the atty posts. If your standard is at the atty then no 200W mod will measure up, you will need in excess of 200w to get 200 at the atty posts. I still feel fine with this measurement standard as I think the real world conditions are too hard to anticipate/pad numbers for. I also believe the dna200 is the best regulated mod available at the moment, so it's a good mod to measure against. Back to the origin of this thread I mostly take issue with the theoretical 200w's not even being available (IE 25A limit on the fuchai).

 

[digatel]

Interesting.

[VapingBad]

Mod resistance setting and as your friend said atty resistance will affect it, get the mod resistance right and a really good (very low res atty) and you should get better results.  The mods are essentially providing the power to the 510 and some is dissipated in the atty.

[Arvidx]

Still curious here since mod resistance is typically in the 3rd digit from what I'm seeing.  As in .003 range so that would not chop this much off.  Also how do you measure voltage without including the heating element in the circuit?  Wouldn't the device see the voltage potential across the entire circuit not 'pre 510'.  I'm still rather curious about how this works out.