Voltage loss/drop/magic delta?

[Rampage V8ps]

Hello,

I've been reading posts for over a year now... Finally created an account and decided to ask a question...

So here's the long and short of it:

I have a mechanical mod, and when testing the voltage output at the firing pin (under load) it's give or take an exact match to the remaining voltage in my battery. (Awesome)

Currently I have a dual coil .35ohm in a nimbus. My nimbus has a resistance of .5ohms (.85ohms total resistance)

However suddenly my coils (28g KA1 wire 3/4 wrap) seem to be taking longer to heat up... Same setup for three months no problems till yesterday. Re wrapped today with the same issue.

So I took a reeding at the positive post and each negative post and found I was loosing .5volts from the firing pin to the coils. (Ex. At pin a reading will be 4v at posts of nimbus 3.5v) HUGE DIFFERENCE!!!! Almost 4w of power lost.

My question is. Is this normal? Or am I taking my readings wrong? Does a nimbus really "eat" .5v? Or is it not functioning as expected?

any help would be greatly appreciated!! Thank you in advance and happy vaping

ps batteries are aw 18650s well maintained varying in age between three months to a week old

 

[AttyPops]

Just a guess:

Clean all contacts 1st and retest. Firing button pin too. Threads. Battery contacts. Battery. Everything.

 

[Ryedan]

Hello,

I've been reading posts for over a year now... Finally created an account and decided to ask a question...

So here's the long and short of it:

I have a mechanical mod, and when testing the voltage output at the firing pin (under load) it's give or take an exact match to the remaining voltage in my battery. (Awesome)

Currently I have a dual coil .35ohm in a nimbus. My nimbus has a resistance of .5ohms (.85ohms total resistance)

However suddenly my coils (28g KA1 wire 3/4 wrap) seem to be taking longer to heat up... Same setup for three months no problems till yesterday. Re wrapped today with the same issue.

So I took a reeding at the positive post and each negative post and found I was loosing .5volts from the firing pin to the coils. (Ex. At pin a reading will be 4v at posts of nimbus 3.5v) HUGE DIFFERENCE!!!! Almost 4w of power lost.

My question is. Is this normal? Or am I taking my readings wrong? Does a nimbus really "eat" .5v? Or is it not functioning as expected?

any help would be greatly appreciated!! Thank you in advance and happy vaping

ps batteries are aw 18650s well maintained varying in age between three months to a week old

Here's the best explanation of checking voltage drop I've seen. Have fun!

 

[Rampage V8ps]

Tried that... Issue is occurring between rda 510 threads and coils. Cleaned with 100 ISO and brush. No change

How do you read output voltage on an RDA with 2 negitive and one positive post?

 

[Ebred]

Ok I am going to assume that your coils are exactly the same resistance. You have dual coils set in parallel with each other with a combined resistance of .85 Ohm.
To Calculate the total resistance of the circuit, this is the formula:
R(Total) = 1/ [(1/R1) + (1/R2)]
So if your R1 and R2 are the same and your R(Total) = .85 Ohm then:
.85Ohm = 1/(1/(2/R) --> .85Ohm * 2 = R -->1.7 .... Sorry that looks awful.

So each coil you have on your dual coil setup is 1.7 Ohm


Anyhow...
Voltage loss across a resistor is linearly proportional to the Amperage that flows through it.

If the readings you are getting now, differ from your previous results then it may be a function of an internal resistance change in your coil, due to perhaps stretching or something.

.5 volts drop does not seem unreasonable though

 

[Ebred]

I guess what I really mean to say is that you will loose voltage across a load. measure the voltage before the load and you will have the battery voltage. The difference of the voltage before and after load will be your voltage loss.
So as you increase amperage your voltage drops more. Ohms Law v=IR

 

[Rampage V8ps]

I guess what I really mean to say is that you will loose voltage across a load. measure the voltage before the load and you will have the battery voltage. The difference of the voltage before and after load will be your voltage loss.
So as you increase amperage your voltage drops more. Ohms Law v=IR

I totally get what your saying. I thought I was taking the reading before the load... on the posts them selfs..

By any chance do you have a nimbus? Or any single positive dual negative post RDA's? it you have coils installed and take a reading with your multi-meeter (black lead on one negative post and red lead on the single positive post) do you loose .5 volts from battery voltage?

Anyways thank you for your reply

 

[Raycecar]

.5 voltage drop is very reasonable. What mechanical mod are you using?

 

[Ryedan]

How do you read output voltage on an RDA with 2 negitive and one positive post?

Not sure if this was answered yet. If your battery is positive contact up in the battery bay (on the 510 connector), put DMM positive probe on the positive post. Negative on either negative post or on the deck between them. Fire mod.

 

[Ryedan]

By any chance do you have a nimbus? Or any single positive dual negative post RDA's? it you have coils installed and take a reading with your multi-meeter (black lead on one negative post and red lead on the single positive post) do you loose .5 volts from battery voltage

Voltage drop measured this way is not only dependent on the mod. Two other very important variables are the battery and the coil resistance. This post explains the intricacies very well. Until you get a better understanding of what you are really measuring here, you will not be able to accurately interpret the number you get.

 

[Rampage V8ps]

.5 voltage drop is very reasonable. What mechanical mod are you using?

It seems high... Fully charged (4.2v) aw imr is reading 3.7v

The mod I'm using in this setup is a bagga

 

[Rampage V8ps]

Wow thank you so much. That's a good thread