FT Magma Voltage Drop

[AppalachianFury]

So I pulled out the voltmeter and did some testing on my current setup. I began with my battery (mnke 18650) weighing in at 4.1 fresh off my i4. Then the bat in the mod (4nine copper clone) at the 510 connection, came to 4.05. All sounds sufficient, until I screw on the rda. Reading from the posts on a .6 ohm coil I get 3.4 volts!

This is is with a freshly cleaned mod, no patina on threads or contacts.

I can realy tell that the coil isn't getting the power, and it's killing my batts.

How ow can this be? Is it the mod, the rda, the batt? I have heard about the infinite clones of the magma having similar issues, so I'm hoping that a new rad will solve my problem. Any thoughts?


By the way, I'm posting in the mech mod forums because the issue of voltage drop seems to be primarily listed in this category. Moderators, please rectify if incorrect. Thanks!

 

[duc916]

I think you have a hybrid top cap on that 4Nine? Sounds like it's shorting out there (the positive tip of the battery may be finding a direct path to ground).

edit: sorry, I read more carefully... looks like a voltage drop somewhere in the mod. Does it get unusually warm anywhere?

 

[AppalachianFury]

I think you have a hybrid top cap on that 4Nine? Sounds like it's shorting out there (the positive tip of the battery may be finding a direct path to ground).

edit: sorry, I read more carefully... looks like a voltage drop somewhere in the mod. Does it get unusually warm anywhere?

Not not at all actually. I'm having similar performance issues with another mech. All connections seem to be solid.

 

[duc916]

I had similar problems with my Akuma clone recently, and despite the brass top cap being cleaned with alcohol, my ohmmeter showed it was reading 1-2 ohm across the surface of it. I went at it with some Mother's mag polish (and did all the mod's threading and firing switch while I was at it), followed by a hot water rinse of everything, then wiped down everything with isopropyl, and the problem was solved. Sometimes alcohol alone isn't enough to remove the layer of oxidation.

Try touching different mating points (threads, pin surfaces, etc.) with your ohmmeter probes lightly and look for readings similar to touching the probes together (0.2 ohm with most meters). If you have to "stab" through the oxidation layer to get a good reading, then you need to polish it.

 

[KenD]

Voltage drop is measured under load, i.e. with an atty. The lower the resistance, the more severe the voltage drop. A drop of .7 is rather high on a .6 ohm coil though. What's the internal resistance of the battery you're using, that plays a major part in voltage drop. For example, my LG he2s and Sony vtc4s with an internal resistance of 12 milliohms or so (don't remember the exact specs) cause a much lower voltage drop than my Panasonics with a higher internal resistance.