Are the Samsung 25R's safe at .15 ohms using an IPV4?

[paulparnham]

What's the point of building so low on ANY mod?

Now take that point and add the ability to maintain steady performance of the build without any voltage drop, and there is your reason for building it for a regulated mod.

u need to build low on a mech to get the heat u may need.
I like a warm vape so I need to build low on a mech otherwise its too cool for my needs but on a vw mod building so low is pointless.

 

[Completely Average]

u need to build low on a mech to get the heat u may need.
I like a warm vape so I need to build low on a mech otherwise its too cool for my needs but on a vw mod building so low is pointless.

What if you don't have the chamber and chimney space to keep a big coil fed with the right amount of air and cooled?

All attys are not equal. An atty that works well with a really low ohm coil might be too small and restricted if you build a larger coil in it. Surely you've heard the old expression "If it ain't broke don't fix it". If he's found a coil setup that works best for him in the atty he has he may be better off regulating that build than he would be trying to build a higher ohm coil in the same atty to try to get the same results. It may not be possible to get the same results with a larger, higher ohm coil in that atty.

 

[justinlm24]

I am running a single 25r in my sx mini right now on a .19 ohm dual kanthal build. Run it between 60-70 watts. I haven't had no issues. I wouldn't personally go up to 100w.

 

[Monotremata]

You may want to reread his post. It takes more current from the load side of the chipset not the batteries.

100w is going to put the same load on the batteries no matter what the resistance of the coil is

Oh boy.. I guess mod makers use magic now to make it happen.

 

[BababooeyHTJ]

Oh boy.. I guess mod makers use magic now to make it happen.

What magic?

 

[Monotremata]

The magic you claim makes 100w pull the same load from the batteries no matter what the resistance of the coil is. Lower resistance and lower voltage BOTH pull more amps from a battery at a set wattage. Its scientific fact, regardless of what you think the chipset is doing. The chipset doesnt magically reduce the amps pulled from a battery, in fact it requires more overhead to regulate it. Theres no way around it. I can see it on my Vamo when I set the display to show amperage, I can derive it using the formula of Ohm's Law on a piece of paper. Its basic electricity there is no way around it. If 100w is pullng the same amperage at 0.5 ohms/3.0v as it does from say 1.5 ohms/4.2v then your mod is lying and is not putting out 100w in both cases.

 

[BababooeyHTJ]

There is a difference between the current that the mod is drawing from the battery and what the coil is drawing from the device. The batteries put out a consistent voltage. The mod is putting out a variable voltage.

Yes, there may be some differences in efficiency. If a mod is putting out 100w I'm sure that its drawing more from the device. That aside what is the difference as far as the batteries are concerned between a .15 ohm coil at 3v and a .3 coil at 6v? In the case of the batteries the "load" is the chipset.

 

[BababooeyHTJ]

Do you think that the current is the same before and after the transformer at your street? There is a reason that transmission lines are a higher voltage than what gets fed to your house Its to not have to deal with voltage drop (not so much an issue here) and to reduce current on the lines allowing smaller gauge wire. You can think of your batteries running at 7.4v as the transmission lines. You can think of the chipset as the transformer. The load side of the chipset is what gets fed to the atomizer. You can think of as the load side of the transformer or the 240v that gets fed to your home. Same principle somewhat.

Is a lower resistance coil going to put more stress on the device? I'm sure. Do we really know how it effects efficiency? I haven't seen any measurements but yihi is pretty good about specs. So this may not be too find out. I wouldn't go lump ever chipset into the same boat. I'm sure that they all perform differently. I've seen pc power supplies come a long way in the past few years with efficiency and voltage regulation.

 

[Mooch]

Typically, efficiency for these chips runs in the 93%-97% range. The efficiency can change based on the amount of current flowing and the difference between the input and output voltages, but usually by less than a couple percent.

Buck-boost boards often run less efficiently than buck-only boards but usually only a couple percent worse, if at all. And that's usually just when the input voltage is at its lowest and the chip is outputting the most current. A lot depends though on the design and what compromises were made to achieve a certain price point, size, shape, etc.