Why so little love for series mech box mods? Have parts on the way for #1 and seriously considering triple 18650 @ 11.1V.

[johndoe1027]

Hey all. Have been wanting to try my hand at building a basic mech box mod. I have all of my parts on the way and my buddy was asking why I was going to wire it parallel and try to make it handle 60 amps (in theory, I can't vape that hot, I just like headroom). Why not wire 3 batteries in series, raise the resistance by X9, thereby lowering the amperage by 1/3 and keep the same wattage? My current single 18650 build is at 32.3A and 135.7W. That's seriously taxing that poor little battery. If I had three 18650 in series it would be 10.7 amps for the same wattage. Same wattage means the same vape, more or less, no?

So ECF, I come to you asking the same question. How is this NOT a better idea? Less amperage through the switch, same draw per battery as a single battery mod (right?), higher ohms with the same clouds etc.

I see a few series mods here and there but the vast majority are parallel. Just wondering what I'm missing. I feel like this is too simple and too good to be true for so few people to be doing it. With batteries already at 35A, 3 of them gives you a real world possibility of 441W (if you like a plasma vape). Two batteries in series at 20 amps gets you 168W which is a beastly vape for only 20A per cell.

To reiterate, I don't vape at 400+W and would only do it once just to see how terrible it really is. And of course, BECAUSE I CAN. Then I'd probably drop back to 100-125ish where it's enjoyable and know in my heart that my mod will last a LONG time.

Thanks for any advice you guys and gals may have. I'm looking forward to building this bad boy regardless of the topography. Using a Hammond 1590B, FatDaddy 510, ebay voltmeter, and for now one of the Chinese ebay "60 amp" DC push button switches. No sled, all copper contacts and will probably go with 12ga stranded wire unless there's room for 10ga, because what the heck. If I do go w a series setup I may use 12ga solid wire, but I have all of the above on hand, can decide when the time comes.

Thanks to several members here (Quigsworth and others) I'll be designing a true mechanical switch for serial #002 using relay contacts.

Edited to add, I know about Mosfet designs and will not be using one for this particular mod. I want a mod with no chips. No need to bring them up. Just gonna use some copper and a switch. Might get fancy with a voltmeter.

 

[Visus]

This really needs some research into fog machines and how they keep that wick wicking.

Just buy a fog machine the're 250 to 600 watts machines for 30 bucks for the research lol..

My biggest wattage vape was 100 watts, I have no idea how you guys vape at those high watts if replacing smoking.
I get the shakes and when waking my eyes sometimes crusty and develop oily blurs most of the day after 50 watt clouds all day..
They are great tho tasty and perfect temp..

stay safe check your volts frequently marry your batts..

 

[johndoe1027]

Haha the fog machine reference was already made by my older non-vaping co-worker, just after I explained the general concept of vaping to him. He used to make homemade fog machines when he was younger. He was just putting the wrong kind of juice in them. ;-)

I don't care to vape above the heat I'm at and when I rebuild my coil it will be lower. I'll still be around 100W though because I like to blow clouds. I got the shakes when I started dripping too. I use 2mg (or lower) juice now.

My question has less to do with super high wattage vaping and more to do with the safety of parallel vs series box mods. People are out there vaping at 200+W. Why they are doing it on parallel mods and not series is the thing I can't figure out at the moment.

 

[rhelton]

Ive never seen anyone vape over 100w or 90w for that matter on a regular basis. 35w to 50w Ill buy into that.

Braggin rights I suppose. Maybe this will help you

http://www.e-cigarette-forum.com/fo...y-box-unregulated-box-mod-450w-build-log.html

 

[edyle]

Hey all. Have been wanting to try my hand at building a basic mech box mod. I have all of my parts on the way and my buddy was asking why I was going to wire it parallel and try to make it handle 60 amps (in theory, I can't vape that hot, I just like headroom). Why not wire 3 batteries in series, raise the resistance by X9, thereby lowering the amperage by 1/3 and keep the same wattage? My current single 18650 build is at 32.3A and 135.7W. That's seriously taxing that poor little battery. If I had three 18650 in series it would be 10.7 amps for the same wattage. Same wattage means the same vape, more or less, no?

So ECF, I come to you asking the same question. How is this NOT a better idea? Less amperage through the switch, same draw per battery as a single battery mod (right?), higher ohms with the same clouds etc.

I see a few series mods here and there but the vast majority are parallel. Just wondering what I'm missing. I feel like this is too simple and too good to be true for so few people to be doing it. With batteries already at 35A, 3 of them gives you a real world possibility of 441W (if you like a plasma vape). Two batteries in series at 20 amps gets you 168W which is a beastly vape for only 20A per cell.

To reiterate, I don't vape at 400+W and would only do it once just to see how terrible it really is. And of course, BECAUSE I CAN. Then I'd probably drop back to 100-125ish where it's enjoyable and know in my heart that my mod will last a LONG time.

Thanks for any advice you guys and gals may have. I'm looking forward to building this bad boy regardless of the topography. Using a Hammond 1590B, FatDaddy 510, ebay voltmeter, and for now one of the Chinese ebay "60 amp" DC push button switches. No sled, all copper contacts and will probably go with 12ga stranded wire unless there's room for 10ga, because what the heck. If I do go w a series setup I may use 12ga solid wire, but I have all of the above on hand, can decide when the time comes.

Thanks to several members here (Quigsworth and others) I'll be designing a true mechanical switch for serial #002 using relay contacts.

Edited to add, I know about Mosfet designs and will not be using one for this particular mod. I want a mod with no chips. No need to bring them up. Just gonna use some copper and a switch. Might get fancy with a voltmeter.

1:

If I had three 18650 in series it would be 10.7 amps for the same wattage. Same wattage means the same vape, more or less, no?

Basically yes.
(There's a difference - you'd be using higher resistance coils.)

2:

How is this NOT a better idea? Less amperage through the switch

That's true; higher voltage means less amps through the switch.

3: Safety.
The answer to the question is parallel lithium batteries are supposed to be safer, and definitely better for the batteries themselves.
With series batteries, (which is the same as battery stacking), they are more likely to run the risk of battery imbalance

 

[johndoe1027]

Ive never seen anyone vape over 100w or 90w for that matter on a regular basis. 35w to 50w Ill buy into that.

Braggin rights I suppose. Maybe this will help you

http://www.e-cigarette-forum.com/fo...y-box-unregulated-box-mod-450w-build-log.html

I guess "regular basis" is what might be different for me than a lot of folks. I don't get to vape all day. None at work and not inside at home either. I get short sessions several times per day and by "several" I mean 5-6. When I get to vape, I like to go hard. My current setup is a Mutation X RDA with a chuff style cap @ 0.13 ohm on a Stingray X mech mod. It's angry, thirsty and I can't hold the button for more than 4 seconds but the clouds are awesome and I like it. That's 135W on a fully charged battery. I don't give a crap about bragging rights. I do want to vape safely (and without IC chips). Not to mention that I'll be rebuilding at around 0.2 ohms sometime later this week when I get time. I'd rather hold the button for longer and not be pushing my battery to it's limit (which is what I'm doing now).

Also, I read that thread, twice. There's a lot of crazy (mis)information in that thread. He's basing everything on at least 4x what I would feel safe doing, from the batteries to the wire and the mosfet chips as well. That's exactly why I started thinking about higher voltage in a mech box. I was thinking about wire for a 60A parallel build and realized using 8GA stranded wire was not space-effective. I'm looking at a 0.36 ohm coil on this build to get clouds like he is getting with 0.04 but doing it completely SAFELY. It's kind of apples and oranges IMO.

To re-reiterate, I won't be vaping at 400W but why would I build a mod that is taxing EVERYTHING IN IT to get there, when I could do it safely instead? I'd much rather be vaping at 25% of my mod's capabilities than right at the edge, which is what a lot of cloud chasers are doing right now. So back to my original question, why would someone use a parallel mech box mod vs a series mech box mod? ESPECIALLY when you go to 3 batteries?

edyle, thank you for your response. I was wondering about battery imbalance in this scenario and had already decided that buying the batteries from the same batch, at the same time, and marrying them was the only way to go.

 

[johndoe1027]

Maybe edyle has brought up the "achilles heel" of the series mech box mod. Battery pairing. Off to look into this tidbit of vaping/li-ion knowledge.

I'd like to take this opportunity to say that I am new to modding and relatively new to li-ion cells. I'm still learning. That's why I'm asking here before I build something and put it up to my face.

 

[edyle]

edyle, thank you for your response. I was wondering about battery imbalance in this scenario and had already decided that buying the batteries from the same batch, at the same time, and marrying them was the only way to go.

Yes; as long as you are going to be following the battery stacking protocol, getting them from the same batch; marking them A and B, alternating them; checking them with a meter to verify that they are matched.

It doesn't matter with non-rechargeables, but it matters with rechargeables;
and it matters with Lithium batteries because of the low voltage issues where you don't want one of your lithium batteries dropping to low.
2.5 + 4.2 = 6.7
You might have a dangerously low battery in series and not know it till you take it out and test it individually.


It's not so critical with parallel batteries.

 

[johndoe1027]

Aha. Light bulb moment. My "boat anchor" answer is a 3-way switch before the voltmeter that checks each cell's voltage individually. Hmm, clicking "post" before I start thinking about the need for diodes and more circuitry than I really want. This was supposed to be simple... ;-)

"Has multimeter, will travel."

I really won't worry about that too much yet as I find myself deciding that my battery needs a charge when it's @ 3.8V. The other night I was worried that I had over-discharged it and it was at 3.65.

 

[Visus]

Use a 3s lipo when a cell is not balanced and goes limp it starts to swell.
The chargers are cheap and fast and power abundant some 3s batts are 1kw so you can vape hugeeeee.
lol

 

[johndoe1027]

I might start looking into other batteries but for now I'm going to start with 18650. If this works like I think it will, I won't need to go to esoteric batteries that are only available online. If the box is capable of more power than your lungs can handle, with headroom to spare, on batteries that most vape shops have in stock for $12/ea, I'm good.

If the 1590B triple batt @11.1V works out the next one will be a 1590G box with dual batts @7.4V. Should be more than enough for me and any normal vaper.

Going to read up on undervoltage protection and fusing to see if a truly safe high wattage "mech" mod is a doable thing. I'm confident that I can insert the batteries correctly and build my coils appropriately but it would be nice to be able to hand it off to someone and not worry, no matter what they do.

 

[rhelton]

Well "go hard" to your hearts content. Post some pics of it, and maybe a video of what that means, I would like to see. .

 

[johndoe1027]

I'm sure you've seen plenty of cloud chasing vids. I'm not even to that level. I have a single 18650 mech mod. I just mean that I chain vape 10-12 hits @ 0.13 ohm. I just rebuilt my RDA with smaller wire (26ga) at 0.18 and I like the vape a little better plus I feel a lot better about running a single 18650 at 23A vs 32A. I use the purple Efest 35A batteries so 32 was cutting it a little close for my comfort.

Edited to add... If it's past 10pm EST - I have had a "few" drinks. And by "few" I mean 8.

Also, I LOVE writing run-on sentences. Because that's how I think.

 

[rhelton]

lol well hope your not hung over tomorrow. My pot on my raptor quit on me, im back on the nemesis. It works ok, but I got used to 5 volt vaping every hit thats powerful and even more so when you hit 6 volts, I dont go there often.

 

[dr g]

The answer to the OP's question is safety. You are tripling down on an unsafe proposition by going with a triple stacked unprotected device.

 

[johndoe1027]

The answer to the OP's question is safety. You are tripling down on an unsafe proposition by going with a triple stacked unprotected device.

Ok, I like the way you think. Thanks for posting. I have decided to fuse this device but didn't manage to post that here yet. The more I think about and design this, the less "mechanical" it's getting. I'll still be using no chips and the current will pass through the switch but there will at least be a voltmeter and fuses.

Dr G, do you think running at anything more than 3.7V is an inherently bad idea? Even if it's fused? Thanks again for helping.

Another thing I'm wondering about is coil life. To get the higher ohms (and a quick ramp up) at the lower current I'll need to use smaller wire. Will 28 or 30ga hold up at the higher voltage?

 

[dr g]

Ok, I like the way you think. Thanks for posting. I have decided to fuse this device but didn't manage to post that here yet. The more I think about and design this, the less "mechanical" it's getting. I'll still be using no chips and the current will pass through the switch but there will at least be a voltmeter and fuses.

Dr G, do you think running at anything more than 3.7V is an inherently bad idea? Even if it's fused? Thanks again for helping.

Another thing I'm wondering about is coil life. To get the higher ohms (and a quick ramp up) at the lower current I'll need to use smaller wire. Will 28 or 30ga hold up at the higher voltage?

Without per-cell safety features, yes it is a bad idea. Whether the wire holds up depends entirely on the resultant wattage and the temperature the wire reaches.

Honestly though, the days of unregulated are numbered with the advent of temperature control.

 

[mberlinger3]

Without per-cell safety features, yes it is a bad idea. Whether the wire holds up depends entirely on the resultant wattage and the temperature the wire reaches.

Honestly though, the days of unregulated are numbered with the advent of temperature control.

I totally though that amperage control would be the new big thing before the dna 40 threw a curve ball. I just don't understand why everyone wanted unregulated mods, short of it just being simpler to set up but I think spending a few extra bucks on a regulator keeps things from blowing up in your face.

 

[dr g]

I totally though that amperage control would be the new big thing before the dna 40 threw a curve ball. I just don't understand why everyone wanted unregulated mods, short of it just being simpler to set up but I think spending a few extra bucks on a regulator keeps things from blowing up in your face.

or inhaling anything burning!

 

[johndoe1027]

I understand people's desire for regulation of all kinds. It's a great thing and I'm glad to see continual innovation in that area. I see a lot of unregulated box mods being made and sold though so it seems that there are others like me that enjoy the simplicity of the mech. I have high resolution audio files (24 bit 96kHz) that sound fantastic but I still listen to vinyl from time to time as well. I like robust simple circuits.

In addition to a nice mech I would like to also have a computerized mod that adjusts my wattage 1000 times per second based on my coil temp, remaining battery voltage, wick saturation, ambient temperature and mood. ;-) I want to build and tinker though and I'm not ready to build a regulated device yet. I've been using mech mods for several months now and it works great for me. I treat my vape gear the same way I treat firearms and motorcycles. I stay a little bit scared of them. The day I quit being scared I'll put it down until I'm scared of it again. That keeps me careful and mindful.

Maybe I'm just hard headed but I don't see why a mech can't be capable of delivering as much power as you'd ever want AND STILL BE SAFE. Proper fusing plus low voltage indication (per cell) covers a lot of potential risks no? I'm not trying to be argumentative, I'm just wondering why this is such a bad idea and seeing if I can make my mech safer. Then I can decide if I want to go with series or parallel. ATM series still seems better than building super low ohm on a parallel mech box.

I'll give this thing a try. I'll wear protection the first time out and be testing everything with an IR temp sensor as I go. I'll either be really happy with what I've came up with and made or I'll be back to say that you were right and it either sucked, blew up, failed or all 3. I'm not terrified of the concept in general as I have seen a few dual series devices out there that have zero protection of any kind and people are vaping away happily with them.

Speaking of which, I think I'm going to go vape a few ml of juice right now. Earlier I measured up for the bottom spacer and divider I need. The switch won't be in until next week so I'm not in a rush. I have a lot of fuse research to do in the meantime anyway.

I appreciate everyone's advice and help with my crazy idea. You all are the best.