Dual paralel mosfet box mod only firing one battery

Absolutelee

• Dec 26, 2014

• #1

So my friend and I built a dual parralel 18650 mosfet box mod about a month ago. The mod is now only firing with one battery slot on the sled. It happens to be the side that the 510 is connected to, which is weird to me. Any ideas of how this could happen?

See attached photos.

 

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Oggy

Silver Contributor

Member For 4 Years

• Dec 26, 2014

• #2

From what I see your sled is wired wrong. Both of the positive sides should be connected together. Here is a wiring diagram originally posted by @CJ

 

Absolutelee

• Dec 26, 2014

• #3

Oggy said:

From what I see your sled is wired wrong. Both of the positive sides should be connected together. Here is a wiring diagram originally posted by @CJ

Click to expand...

Thank you for the quick reply. The first picture shows where I soldered a wire connecting the positive leads. The same technique was used on the negative leads.

This is what confuses me. If there was a break in the circuit, neither side should work, right?

 

freemind

Gold Contributor

Member For 4 Years

Member For 3 Years

• Dec 26, 2014

• #4

You soldered your wiring wrong bro.

Your lead from the 510 should NOT be tied to the positive clip on the battery like that. I do NOT see a connecting lead between the two positive clips on the sled.

 

Oggy

Silver Contributor

Member For 4 Years

• Dec 26, 2014

• #5

I have not done a mosfet yet so I am guessing here. With the diagram above the positive is always "on" to the 510 center pin. The mosfet just completes the circuit to the neg so the box fires. If the jumper on the pos isn't making a good connection this would cause only one battery to drain. The other battery is only pulling enough power to fire the mosfet. If you have a multi-meter check the continuity of the pos post to see if they are making a connection.

 

Oggy

Silver Contributor

Member For 4 Years

• Dec 26, 2014

• #6

I can see it in the first pic, but the pics are blurry.

 

Absolutelee

• Dec 26, 2014

• #7

Here is another view

 

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Oggy

Silver Contributor

Member For 4 Years

• Dec 26, 2014

• #8

I would check your jumper, to me its the only thing that makes since.

 

CourtneyPoop

• Dec 26, 2014

• #9

Your wiring is just fine as long as the connections are tight. Make sure your positive and negative leads are tightly soldered to your sled on all four contacts. The answer to your question on whether the mod can fire without both leads being connected is YES, it will fire if the 510 is connected and the other lead isn't.

I hope this helps. Check your solder on all 4 battery sled connections and let me know.

 

Absolutelee

• Dec 26, 2014

• #10

Confirmed. It's the jumper connection. Fixed. Thanks everybody!

 

Oggy

Silver Contributor

Member For 4 Years

• Dec 26, 2014

• #11

NP glad you got it working. Should make a big difference with battery life

 

Diescum88

Gold Contributor

Member For 4 Years

• Dec 31, 2014

• #12

You don't have a MOSFET wired into it?

 

Oggy

Silver Contributor

Member For 4 Years

• Dec 31, 2014

• #13

The mosfet is wired in on the neg side to keep voltage drop down. The pos is going straight to the 510.

 

R

rob1217

• Feb 14, 2015

• #14

I have a ciggreen 7 box mod and just noticed today that only one of the batteries is firing. Any ideas? The site where the battery is the one that is firing.

 

Last edited: Feb 15, 2015

BigNasty

Diamond Contributor

Member For 4 Years

ECF Refugee

• Feb 15, 2015

• #15

rob1217 said:

I have a ciggreen 7 box mod and just noticed today that only one of the batteries is firing. Any ideas? The site where the battery is the one that is firing.

Click to expand...

Don;t fuck with cigreen stuff.

 

SteamCraftKyle

• Feb 16, 2015

• #16

Hello, box builder here. Your issue is your jumper wires. You incorrectly wired the top AND bottom jumpers. The contacts need to be bridged in order for voltage to be able to travel the proper way. Here is a picture of one of my MOSFET boxes I built a while ago. Feel free to ask me anything.

EDIT: Just saw you got it working, congrats

 

Jackson

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Member For 5 Years

• Feb 17, 2015

• #17

rob1217 said:

I have a ciggreen 7 box mod and just noticed today that only one of the batteries is firing. Any ideas? The site where the battery is the one that is firing.

Click to expand...

You comment is confusing, "site where the battery is the one that is firing" makes no sense.

Looking at the mod I like what I see, a rather elegant approach.

The top battery (pos) is a solid plate and the switch contact is solidly mounted to it. Seems that part should be fine as you say it fires. I would check the bottom NEG contacts, if you own a multimeter see if there is continuity, touching both should give you a beep (if your meter has that function). Multimeters make this kind of troubleshooting a breeze and they don't need to be expensive, this one has a beep for continuity and auto shut off. For a vaper and with light use it should be fine.

Meter XL-830L

The 2 bottom contacts should basically be functioning like one solid bar.

That said this is such a simple design, Make sure your POS contact points (the nubbins on the top plate) are in fact making contact with your battery and are clean, that same with the bottom bent tabs.