Voltage Drop Technical Details

[razorx]

Hey Everyone,

I ran into a problem that I think someone must have experienced before me and I would be so grateful to anyone who could help. I am creating the typical circuit of an e-cig: I have a AA sized 14500 Lithium ion battery (2000 mAh, 3.7 volts) connected to a coil with 6.8ohms (i can change this but the coil i tested happen to be a bit long).

From ohm's law, the current output by the battery should be .54 amps (3.7/6.8). When I run the circuit, I measured with my multimeter that I was getting the .5 amps but my voltage had decreased to less than 1 volt. This means my Power (voltage*current) was very low, so my coil was barely warm to the touch. I do not understand why the voltage is dropping so much because I have a high mAh. Does it have something to do with the c rating?

Please help! Thank you so much!

-razorx

 

[dangkhoa02106]

The resistance of your coil is too high. Q=I^2*R*t, the resistance of the coil will increase when it hot.

 

[Switched]

Do not know what you are trying to explain but I can guarantee you that battery does not have 2000mAh. 14500s are typically 900mAh and 800 for IMRs.

 

[razorx]

Thank you for both of your replies, they both have helped!

Switched, your response made me question my battery,as it said those specs on the battery but the battery itself was no name and kinda shady. I got some brand name Ni-mh 2000mah which have solved the voltage drop problem.

dangkhoa02106, the Nichrome wire I have just has too much resistance like you said because the current is still low. I am hoping the new wire i get will solve this problem.

I wish there was a karma feature on this forum because its people like you that make this forum great!