First homemade mod!

[crazyarms]

So I decided I wanted to make my own mod a couple weeks back and finally got around to doing it. I ordered stuff from all over the place in attempts to have extra parts just in case. I was able to wire this up pretty quickly and it vapes pretty well. But I metered a huge voltage drop under load and I am wondering how I can go about fixing this. I was running 2 almost new freshly charged vtc4s at 4.2 each and a .3 ohm dual coil setup and my voltage at the 510 was 4.09 and then under load...... 2.65 lol

All the wiring is 20 gauge stranded copper. I wired 2 18650 vtc4s in parallel and used a switch bought from stealth vapes and also the stealth connector from stealth vapes. I have a feeling the connector may be part of the problem along with the thin wire gauge and the long wires I soldering in (been a while since I have soldered anything so I was sloppy). My question to you gurus out there is how can I help my voltage drop issues. I would really like to keep the stealth vapes 510 because it looks awesome. Ideally I am hoping I can just re-wire and solder everything with a thicker wire gauge and less extra wire to get rid of some of these issues. Let me know what you guys think! Pictures below!













Remember this is my first ever homemade mod so constructive criticism is appreciated! I also plan on drilling vent holes just in case, but for now the door stays on very loosely.

 

[granolaboy]

Nice Work!

Where did you get the enclosure? It kinda looks like an AC plug enclosure...I like it

First off, I find it odd that you have 2 batteries at 4.2v, but then they're 4.09v when connected in parallel? That doesn't sound right.

Second, how old are these batteries? At 4.09v and 0.3Ω, you are asking for 13.6A. That's just over 3C, which those vtc4's should handle no problem.

20g wire is a bit light for that amount of amps, but realistically you've only got a couple inches of wire in there, and it only carries the current in bursts, so it's probably not the issue. If the wires get hot at all, then they are losing power, and you should switch em for 18g or 16g. Using high-strand high-temperature silicone wire can handle more current at a lighter guage, and simply moves current better period.

My bet is your batteries are old and tired...that's a ridiculous amount of voltage sag for that load.

 

[Nat79]

From a laymen's pov I would say you need thicker wire, and many of those switches are rated @ 10 amps(intended for switching a regulator). Is there any heat while you fire?

 

[JohnnyDill]

Look into wiring in a MOSFET so that all that current is not going through the fire button. Switch will last forever this way. Looks like you have plenty of room to work with in that enclosure.

 

[crazyarms]

THe enclosure came from mouser. I will look at my order and get you the part number.

I think one of them may not have had a full charge when I did the voltage test last night but this morning they are at full power. Seems to be working quite well. But still does not feel like I am getting a vape from a fully charged battery.

I am hoping its not the batteries! I have had one for maybe 3 weeks and the other for maybe 2 weeks bought from a local B&M. The voltage measurements are not spot on since I did them last night pretty late and just recalling now. I will have to try some other batteries I guess. I am going to be real angry at the shop if they are selling fake VTC4s!

I left the door off for the first hour or so after I finished building and the wires did not get hot at all. So the amount I have in there is not my issue? That is good to know, and if the connections weren't good it would be firing intermittently or not at all so I am assuming my connections are good.

Would I see any improvememtns from a thicker wire gauge? I was contemplating picking up 18 gauge but if 16 would be better is it worth it?

THanks for the input by the way, I am going to test out my MNKE batteries now and will report back.

 

[asdaq]

For a first mod you should be proud. Mine was a hot mess and I didn't even bother to finish it before I went on to the second. The springs are thin and a source of voltage loss. Even when compressed current still travels the length of the thin wire, so those could stand to be replaced. Of the three solder joints I can see the battery terminal on the left looks good, the other two don't look as though the solder flowed and are rather blobbed and stuck on there. When solder flows it looses its surface tension and spreads on the parts to be joined. Almost like it gets absorbed by the parts to be joined. This could be another source of the problem. The others are hidden so it is hard to say. I would tackle the springs first, this will likely make the biggest difference.

Sent from my Nexus 4 using Tapatalk

 

[crazyarms]

From a laymen's pov I would say you need thicker wire, and many of those switches are rated @ 10 amps(intended for switching a regulator). Is there any heat while you fire?

Zero heat except in my atty. I chain vaped it with the lid off and still nothing at all was hot. I think I may try some thicker wire.

 

[crazyarms]

Look into wiring in a MOSFET so that all that current is not going through the fire button. Switch will last forever this way. Looks like you have plenty of room to work with in that enclosure.

I will definitely look into that! So the switch essentially changes from the positive side to the negative side correct? The circuit is completed on the negative rather then the positive if i am under standing the diagrams correctly?

 

[crazyarms]

For a first mod you should be proud. Mine was a hot mess and I didn't even bother to finish it before I went on to the second. The springs are thin and a source of voltage loss. Even when compressed current still travels the length of the thin wire, so those could stand to be replaced. Of the three solder joints I can see the battery terminal on the left looks good, the other two don't look as though the solder flowed and are rather blobbed and stuck on there. When solder flows it looses its surface tension and spreads on the parts to be joined. Almost like it gets absorbed by the parts to be joined. This could be another source of the problem. The others are hidden so it is hard to say. I would tackle the springs first, this will likely make the biggest difference.

Sent from my Nexus 4 using Tapatalk

Thank you!

I had thought about soldering directly onto the top part of the spring to try and eliminate them but I was worried about the compression and that messing with my solder. I am definitely going to clean up the points of solder soon, maybe I will swap wire gauges and make it look pretty. The funny thing about the hidden connections is they are the nicer looking ones lol!

 

[granolaboy]

For a first mod you should be proud.

I'll second that

The springs are thin and a source of voltage loss.

Good call...hadn't considered that. This may be of interest:

Battery holder contact resistance measurements

 

[Nat79]

Zero heat except in my atty. I chain vaped it with the lid off and still nothing at all was hot. I think I may try some thicker wire.

Good to hear, it looks good for your first. Main concern with something like this is melting the insulation and getting a hard short.

 

[crazyarms]

Good to hear, it looks good for your first. Main concern with something like this is melting the insulation and getting a hard short.

I was honestly expecting smoke when I first fired it. I even went outside! But low and behold it fired up great. I will need to look into replacing those springs with something else. Maybe a piece of brass feeler gauge or something. Or I will just order a new battery holder. Any recommendations?

 

[asdaq]

Oh there we go, the keystone battery holders bap lists in that thread are nice. Does your switch have screw terminals? That is a sign of decent voltage rating.

Sent from my Nexus 4 using Tapatalk

 

[crazyarms]

No it does not. I have a switch on order that does but it wont be here for some time. I believe its a switch made for starting a boat and is rated at 25v or something like that. If the current switch gives me trouble I will swap it out.

I am going to order 2 of those keystone battery holders right now!

 

[turbocad6]

I'll bet most of the vd is from the springs, try balling up a bit of tin foil and shoving it in each spring so a battery fits in there snug and then check drop... I'm also a little leary of the ground connection at the atty

the tin foil is not suggested as a permanent fix, more so as a diagnostic aid and a temporary bandaid fix at best

edit: although I will admit to running a ball of tin foil in one of my reo's for a while now, haven't gotten around to building a new good spring for it yet. it is pretty ghetto but truth is is works in a pinch

 

[crazyarms]

I'll bet most of the vd is from the springs, try balling up a bit of tin foil and shoving it in each spring so a battery fits in there snug and then check drop... I'm also a little leary of the ground connection at the atty

the tin foil is not suggested as a permanent fix, more so as a diagnostic aid and a temporary bandaid fix at best

Yeah the ground is quite a large piece of metal. Looks to be silver coated though but who knows. I will try the tin foil and see if thats the issue. I already ordered some new keystone battery holders that should hopefully solve some of the problems. I may also pull the ground off from that connection and solder directly onto the base of the 510 and see if that helps.

 

[jstjoehere]

Just a guess Im no expert by any means but it looks as if you only have 1 ground wore for both batteries and 2 positives. Should have you used a larger wire if thats what was done. I agree with heavier battery springs as well/

 

[edyle]

So I decided I wanted to make my own mod a couple weeks back and finally got around to doing it. I ordered stuff from all over the place in attempts to have extra parts just in case. I was able to wire this up pretty quickly and it vapes pretty well. But I metered a huge voltage drop under load and I am wondering how I can go about fixing this. I was running 2 almost new freshly charged vtc4s at 4.2 each and a .3 ohm dual coil setup and my voltage at the 510 was 4.09 and then under load...... 2.65 lol

All the wiring is 20 gauge stranded copper. I wired 2 18650 vtc4s in parallel and used a switch bought from stealth vapes and also the stealth connector from stealth vapes. I have a feeling the connector may be part of the problem along with the thin wire gauge and the long wires I soldering in (been a while since I have soldered anything so I was sloppy). My question to you gurus out there is how can I help my voltage drop issues. I would really like to keep the stealth vapes 510 because it looks awesome. Ideally I am hoping I can just re-wire and solder everything with a thicker wire gauge and less extra wire to get rid of some of these issues. Let me know what you guys think! Pictures below!

.

1: FIRST:
To mod and troubleshoot, just use the 1 battery so as not to complicate things.

2:
How are you measuring your coil ohms.

3:
0.3/r = 2.65/(4.09-2.65) = 2.65/1.44
r = 1.44x0.3/2.65 = 0.16 ohms
The resistance of your box is 0.16 ohms.

0.16 ohms; yeah that sounds reasonable expectations on a box.

 

[crazyarms]

1: FIRST:
To mod and troubleshoot, just use the 1 battery so as not to complicate things.

2:
How are you measuring your coil ohms.

3:
0.3/r = 2.65/(4.09-2.65) = 2.65/1.44
r = 1.44x0.3/2.65 = 0.16 ohms
The resistance of your box is 0.16 ohms.

0.16 ohms; yeah that sounds reasonable expectations on a box.

I will troubleshoot when I get home with just one battery and see what I am getting.

I am measuring my coils with both a 510 ohm checker and a multimeter and both come out to .32

If it sounds reasonable then maybe I won't troubleshoot too deeply and just use it until I get the urge to build another. I am going to try a thicker wire gauge, new battery holders and some new batteries. Both batteries were not fully charged I don't think last night when I measured everything but this morning I tossed in 2 fresh ones and just went on a vape break outside and it seems to be on par with my other mods. It seems as though it is hitting much harder this morning.

 

[crazyarms]

Just a guess Im no expert by any means but it looks as if you only have 1 ground wore for both batteries and 2 positives. Should have you used a larger wire if thats what was done. I agree with heavier battery springs as well/

Since the batteries are wired in parallel the positives are attached and so are the negatives. So you have the positive going out on one end and the negative on the other. Makes it double the mAh but keeps it at the same voltage.