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Voltage drop under significant load 0.2/0.3ohm for Samsung 25r and Sony Vct4

CurlyxCracker

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Is there any charts or real world information about the comparison of voltage drop between the 25r and vct4? I'm talking low ohm load like 0.2 or 0.3 ohms. I've seen some charts that say the 25r will provide less voltage drop under higher ohm loads but I'm pushing these batteries to the extreme, kinda, specific for cloud competitions and want to get the best battery for less voltage drop. I built a series box so won't be running any lower ohms so the 20A vs 30A ratings as the only time this will have batteries in it is during the competition and I'm comfortable running the 25r that low.
 

State O' Flux

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Click on my last sigline hyperlink. It will redirect you to Mooches vape specific, comprehensive, 18650 battery test blog.

He's tested over 30 18650 cells, and will have the test results for both batteries in question, with comments on voltage sag and operating temperatures at steady state, discharge values, in 5 amp increments.

image-jpg.488494

Link to full size image.
 

CurlyxCracker

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Click on my last sigline hyperlink. It will redirect you to Mooches vape specific, comprehensive, 18650 battery test blog.

He's tested over 30 18650 cells, and will have the test results for both batteries in question, with comments on voltage sag and operating temperatures at steady state, discharge values, in 5 amp increments.

image-jpg.488494

Link to full size image.
Thanks man. Looking forward to the test results. It's $5more for 4 vct4s, which is negligible for that little edge if there is one
 

CurlyxCracker

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Yeah I guess I missed labeled what I'm looking for I want data of battery SAG between the two using a low ohm build
 

Nomuff2tuff

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u can test them youself ,use a single 18650 sled with a multy meter, check with the meter pos and neg on sled then aply to a floating 510 on a jig test it at the neg and pos of the 510, subtract from the first reading at the battery that's your sag , also whatever build you have.
 

CurlyxCracker

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u can test them youself ,use a single 18650 sled with a multy meter, check with the meter pos and neg on sled then aply to a floating 510 on a jig test it at the neg and pos of the 510, subtract from the first reading at the battery that's your sag , also whatever build you have.
Was trying to do it without buying 2 new sets of batteries. I have both but the vct4 is definitely older, which I'm assuming also has a higher internal resistance than a new one by now
 

Jon@LiionWholesale

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I want to know from 4.2 to about 3.9v which battery will provide more voltage to a 0.2-0.3 ohm build.

I assume you mean from 4.2 to 3.9 as measured without any load? If you put a 0.2-0.3 ohm load on a battery it'll immediately drop below 3.9 while under load due to sag, but then if you take it off it'll go back up.
 

CurlyxCracker

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I assume you mean from 4.2 to 3.9 as measured without any load? If you put a 0.2-0.3 ohm load on a battery it'll immediately drop below 3.9 while under load due to sag, but then if you take it off it'll go back up.
Yes. And what I want to know is which battery will sag the least under said load.
 

Mike H.

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Considering a .2 ohm load will draw 21 amps with a full 4.2v, this is safe to use at .2 ohm?

Or maybe i should consider the voltage making it to the atty the key, which would vary due to ohms?

On a .5 ohm load all three of my mechs pulled in high 3.8 to low 3.9v range..so is this the voltage i should consider when figuring out battery safety using ohms law?
 

Jon@LiionWholesale

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Considering a .2 ohm load will draw 21 amps with a full 4.2v, this is safe to use at .2 ohm?

Or maybe i should consider the voltage making it to the atty the key, which would vary due to ohms?

On a .5 ohm load all three of my mechs pulled in high 3.8 to low 3.9v range..so is this the voltage i should consider when figuring out battery safety using ohms law?

Good question. You can see that it's only 21 amps for a insignificantly short period when it's first loaded since the voltage even on the very first load drops to 3.8V or so loaded. So then it's 3.8/0.2 = 19A even in the very beginning after loading it. So even if you're going by continuous specs it's good.
 

Mike H.

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I tend to find zero voltage drop in all of my mech mods at the 510 and only see a drop based on the ohms of the coil..the higher the ohms the less drop i see.

So that being the case it seems a higher ohm coil will put you closer to the max capabilities of the battery as you have closer to the 4.2v as ohms climbs or less of a voltage drop in general.

Am i confused or on point?...lol
 

Jon@LiionWholesale

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I tend to find zero voltage drop in all of my mech mods at the 510 and only see a drop based on the ohms of the coil..the higher the ohms the less drop i see.

So that being the case it seems a higher ohm coil will put you closer to the max capabilities of the battery as you have closer to the 4.2v as ohms climbs or less of a voltage drop in general.

Am i confused or on point?...lol

Are you asking whether a higher ohm coil will mean less voltage drop for the battery? If so yes that's correct.
 

Mike H.

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Are you asking whether a higher ohm coil will mean less voltage drop for the battery? If so yes that's correct.

Well, i knew higher ohms eqauls more voltage to the atty so, no...What im
Good question. You can see that it's only 21 amps for a insignificantly short period when it's first loaded since the voltage even on the very first load drops to 3.8V or so loaded. So then it's 3.8/0.2 = 19A even in the very beginning after loading it. So even if you're going by continuous specs it's good.

Youre saying a 25r would be good due to the burst rating it has?..I tend to like to leave room on the continuous rating..I couldnt trust pulling 19 amps on a 20 amp cell..lol

Thats why i would go with vtc4's at .2 ohm to leave me 9 amps of safety and maybe not push the cell enough to increase heat.

Maybe im over cautious but i dont see that as a bad habit..lol
 

NemesisVaper

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I tend to find zero voltage drop in all of my mech mods at the 510 and only see a drop based on the ohms of the coil..the higher the ohms the less drop i see.

So that being the case it seems a higher ohm coil will put you closer to the max capabilities of the battery as you have closer to the 4.2v as ohms climbs or less of a voltage drop in general.

Am i confused or on point?...lol
The higher the build, the closer you will get to the theoretical amp draw obtained from ohms law, because the assumption of 4.2V will become increasingly accurate. In that sense a higher build will take more advantage of the maximum voltage obtainable.

As you build higher though, as we know, amp draw becomes less, as does the wattage you get. Building higher will never out compensate for voltage sag, you'll always get an over all wattage increase as you build lower, be it theoretical or actual measured.

For me I find it best to place less emphasis on the actual voltage figure the cell is putting out for different builds. For me the voltage is useful as a comparison between batteries to tell me which will provide more wattage for the same build. Tuning your build to get low voltage droop is pointless because you're never going to get the Vape you want by doing that. Low droop need a a low (high ohm) load.

For me the potential of a battery is a combination of its safe amp limit, the Iver all voltage curve on a discharge and the amount of heat it produces doing so. Singling out one characteristic as a battery's potential I don't find useful for me.
 

NemesisVaper

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This is exactly the kind of battery testing I want to see and enjoy reading. Because of articles like yours and Mooch's I feel I'm armed with not only figures for what is safe but a picture of what is happening to the cell as I Vape with it.

How anyone can make reading about batteries interesting is amazing to me. I'm interested in t his kind of thing because I'm a geek, but I challenge anyone to read that article and not agree that the information was presented in such a way that was engaging and kept the subject from sounding dry and too "techy".

Thankyou.
 

Slurp812

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Even the best 30 amp cells will be ~3.8 at best with a 0.20 ohm load while pressing the button. You'd be ok with a 20 amp cell. More headroom with a 30 amp. Cant be too safe...
 

dre

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I've seen drops down to 3.2v on a .15 build with a brand new fully charged 25r and a clean subzero mech.

Sent from my XT1030 using Tapatalk
 

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