Voltage Drop Help

[unstoppablegr]

Hello,
because i am new to Mech mods i'd like you to tell me your opinion.
I measured the voltage drop on my mod
i use a Chi you mod and Omega Dripper
Battery Only : 3.9V ( When fully charged 4.2V) 18650 Efest 2500mAh High Drain
mod ONLY : 3.85V
MOD + Dripper : 2.8 - 3.1V

So that means the dripper isnt good? because i have very little throat hit and i dont think it works pretty well... or this is normal ? because 0.9V - 1V drop is pretty much. What do you think ? I use single coil 0.9ohms

 

[DaveSignal]

As for the voltage drop, if measuring the battery only without the mod gets 3.9V, then something is wrong with your charger or your voltmeter.

As for the throat hit, you need to wrap lower resistance coils if you want more power. I would recommend starting around .4 ohm, then moving up or down to suit your preference. 0.9 is too high for an rda on a mech mod, though. I build most of my rdas at .21 ohm.

 

[unstoppablegr]

What do you mean? when i measure my battery in the morning after charging the meter shows 4.15V, isnt that normal??? Its showing 3.8 - 3.9V now after usage. So whats wrong? :S For example at night after all day use my battery shows 3.6V.

 

[edyle]

Hello,
because i am new to Mech mods i'd like you to tell me your opinion.
I measured the voltage drop on my MOD
i use a Chi you MOD and Omega Dripper
Battery Only : 3.9V ( When fully charged 4.2V) 18650 Efest 2500mAh High Drain
MOD ONLY : 3.85V
MOD + Dripper : 2.8 - 3.1V

So that means the dripper isnt good? because i have very little throat hit and i dont think it works pretty well... or this is normal ? because 0.9V - 1V drop is pretty much. What do you think ? I use single coil 0.9ohms

So on a 0.9 ohm coil, you got about a 1 volt voltage drop.

I'll use 3 as the voltage across the coil;
Current = 3/0.9 = 3.33* amps.
3.9 = 3.33(r + 0.9)
1.17 = r + 0.9
0.27 = r

Your mod plus battery come up to about 0.3 ohms resistance.

 

[unstoppablegr]

Sorry but i can't understand a thing.... can you explain me what's wrong and what i have to do to fix it?

 

[DaveSignal]

What do you mean? when i measure my battery in the morning after charging the meter shows 4.15V, isnt that normal??? Its showing 3.8 - 3.9V now after usage. So whats wrong? :S For example at night after all day use my battery shows 3.6V.

I thought you were saying that your fully charged to 4.2 volt battery measures 3.9 volt by itself.
Your voltage drop is not that great. Is your mod brass or copper? More conductive materials usually perform better.

But the point about your issue of getting weak hits is still the same. lower the resistance of your coils.

 

[unstoppablegr]

Ok i understand pretty much now. But the strange thing is that MOD + Battery = 3.9V and when i measure the voltage from the positive and negative posts of the dripper i get 2.8 - 3.1V is this normal? or it depends on the coil i use?

 

[edyle]

Ok i understand pretty much now. But the strange thing is that MOD + Battery = 3.9V and when i measure the voltage from the positive and negative posts of the dripper i get 2.8 - 3.1V is this normal? or it depends on the coil i use?

1:
The total voltage is 3.9 volts.

When you connect the coil, the voltage drops to 2.8 - 3.1 volts.

Is that normal: I suppose so; people who spend more attention to getting copper mods and shining up the threads and such will get much less drop in voltage.

2:
Yes, the drop in voltage depends on the coil you use.

If you use a lower ohm coil, you will get a larger drop in voltage.

Your mod+battery combo worked out to 0.3 ohms; that means if you put on a 0.3 ohm coil, your voltage will drop by half.

 

[unstoppablegr]

So if i use a lower resistance i'll have 1.5V++ Drop? so i suppose thats bad for the performance. That means i can't do much about that ? If i use another atomizer will i see any difference? sorry for too much question i am new to mods..

 

[Wraith504]

Your battery will drop voltage across any resistance. That is not the true way to really measure your voltage drop anyway. Like others have said. .9 is a bit high on a mech try something around .5 or so.

 

[unstoppablegr]

Ok, i'll give it a try

 

[edyle]

So if i use a lower resistance i'll have 1.5V++ Drop? so i suppose thats bad for the performance. That means i can't do much about that ? If i use another atomizer will i see any difference? sorry for too much question i am new to mods..

On any mod, the lower the coil resistance the bigger the loss due to voltage drop.

You could check your contacts, make sure to keep them clean and shiny, but the chi you is just a regular common mech not some high performance mech; I've got a chi you myself for backup.

If you use higher resistance coils, the voltage drop is less.

I don't think there's anything wrong with your mech, if that's what you're wondering.

 

[93gc40]

Except that the .5ohm coil will result in even MORE voltage droppage. If you want to reduce the affect of reduced volts, you increase resistance, in the coils.

To the OP, Verify all connections between coil and battery.... Could be from loose post, bad connection between bat and atty or even internal connection INSIDE atty or dirt.

 

[Ryedan]

Hello,
because i am new to Mech mods i'd like you to tell me your opinion.
I measured the voltage drop on my MOD
i use a Chi you MOD and Omega Dripper
Battery Only : 3.9V ( When fully charged 4.2V) 18650 Efest 2500mAh High Drain
MOD ONLY : 3.85V
MOD + Dripper : 2.8 - 3.1V

So that means the dripper isnt good? because i have very little throat hit and i dont think it works pretty well... or this is normal ? because 0.9V - 1V drop is pretty much. What do you think ? I use single coil 0.9ohms

OK, so your battery is 4.2V off the charger, but at the time you did the voltage checks above it was 3.9V because you had vaped the battery for a while, correct?

The battery in the mod with no atty on it measured 3.85V when you hit the button, so you lost 0.05V compared to the battery outside the mod, correct?

Does the 0.0X digit on your DMM read in steps of 0.01 or 0.05? In other words, will it read 3.91, 3.90. 3.89, or will it just read 3.95, 3.90, 3.85? If it reads 0.01 you have dirty contact surfaces in the mod that need to be cleaned. If it reads in steps of 0.5V the issue is not clear.

A 1.0V drop under load (when you hit the button and check over the coil) is high unless you're using a very low resistance. At 0.4 ohms I get around 0.4V drop with the same battery you have in a clean SS mod. The higher the resistance the more V-drop under load you'll get.

What do you mean? when i measure my battery in the morning after charging the meter shows 4.15V, isnt that normal??? Its showing 3.8 - 3.9V now after usage. So whats wrong? :S For example at night after all day use my battery shows 3.6V.

So, now you're saying 4.15V and before you said 4.2V off the charger. Is it that it drops to 4.15V after a few hours with no use? My batts come off the charger at 4.2 - 4.21V and will drop to about 4.00 after an hour or two. They stay there for hours before they drop to 4.19V. Again, the resolution of your DMM means a lot here.

 

[duc916]

Sounds like your battery isn't performing well (have you tried another?), or you've got high resistance elsewhere in the mod, either in the top cap or the firing switch.
I'm not sure how you're measuring voltage under load, but the thing about those tankometers is they don't take into account voltage drops across your switch, which could very well be where all the drop is occurring.