my 5v tube mod

[captainbrianbeard]

so i have a 5v box mod using 2 14500's and a regulator and i love it. only thing is ive found it very brittle if it gets dropped or anything, i ve already broke one of the plastic tabs that hold the back piece on.

so ive got an idea for another mod i thought id throw up here for you guys to give me advice and use it as a build up thread. I already have 4 14500's to use with my box mod to im trying to build somthing that i can use my existing batteries and charger.

im going to use a single 14500 and run it though a voltage booster to 5v. My dad is an electrical engineer and he is going to build the booster with me. I've also found some on HobbyKing Online R/C Hobby Store : for about 4 bucks that r/c guys use to run lithium batts instead of nicads. however its a little but too large to fit in the mod im looking into building. it would work perfect for a box mod if anybody wants to use it.

the plans in my head are to use either a copper or aluminum tube with about a 5/8" ID to fit a 14500 in the bottom, the booster above that with a switch and 510 atty connector up top.

a few things i need advice on, what kind of tube to use, and where to get it. I havnt been to the hardware store yet but i assume they have some copper there. my roomate is a machinist and can possible make me a pretty sweet aluminum tube but i'll have to figure out how to make caps unless he can lathe threaded caps for it.

also, if im to stick a battery and my electronics in the same tube im thinking of putting a spring at the bottom where the neg side sits down, using the whole casing as neg for the circuit, and then mayyybe using epoxy to glue a pos contact to a piece of balsa which would be jammed and glued in the tube far enough so the battery will fit snugly in the bottom hitting both contacts grounding on the body and a positive lead coming up through the balsa.

what do you guys think?

 

[lynch]

Ever look at the cigar tubes ? this one I got on ebay, there is a longer part that I havent modded yet.
About 5" and 14500's would be a perfect fit, I made it with 18650 and it's very tight.

 

[captainbrianbeard]

Interesting. I've never thought of those. That might work rather well. Did you make the caps or did it come with them?

 

[lynch]

Interesting. I've never thought of those. That might work rather well. Did you make the caps or did it come with them?

The caps came with it. They still have the one I got on ebay, just put "cigar tubes" in search.
If you really want a good one they have a 14k gold tube for $5,000.00.

 

[captainbrianbeard]

Those look perfect! Might have to make a cut somewhere to shorten it up a little but the tubes look great! Haha I saw that gold one.too. would.make a pretty bad ... mod imo lol

 

[lynch]

Dont think I would put holes in something I paid 5K for

 

[breaktru]

Capt, if this is the booster you were looking at, it is way under powered:
Voltage Booster
Operating Voltage : 2.7V - 4.2V
Operating Current : 1A
Max operating Current : 1.5A

 

[captainbrianbeard]

Capt, if this is the booster you were looking at, it is way under powered:
Voltage Booster
Operating Voltage : 2.7V - 4.2V
Operating Current : 1A
Max operating Current : 1.5A

i saw that one too, 1A is not enough. this is the one that i saw, however, at second glance it says input is 6v-23v. but still might work for other mods. its output is 3A/5V

HobbyKing Online R/C Hobby Store : HobbyKing Micro UBEC 3A / 5v

 

[lynch]

Try this place engineeringshock.com theyhave a booster board 3.4 to 34vdc.

 

[captainbrianbeard]

that will work great! even variable voltage! a little big tho. im trying to build a 5v system into a tube with a 14500. im starting to doubt if its possible :/ well, possible that is on the small scale of being an all day pv id want to carry in my pocket. I believe the box mod im using has a linear regulator which ive heard is not very efficient. The extra 3v of power is just being wasted and tossed out as heat. Another like my box mod can be easily made into a tube. But id like to try and keep it as small as i can if its even possible.

 

[lynch]

Dont know if you can get it that small to fit in the tube, but was thinking you can get 4.8 battery at madvapes and those bats need a special charger that they sell. At least you can get near 5 volts with one bat.

 

[captainbrianbeard]

Is it a nicad?

Edit- nvm nimh

Interesting idea tho, not sure about battery life tho

 

[lynch]

I get about 5 hours but I chain vape. Did you check out totallywicked.com ? They have a new item called "Tornado buster" can turn any bat into 3.3-4.7 volts sounds just what you want ? comes in black or silver but the black is now sold out.
Sounds great to me only knock is the price..... $64.99 OUCH !!!

 

[captainbrianbeard]

wow, yea ive been looking at madvapes' maxi roughstack v2 which looks pretty cool. two 3v batts would probably work for me as well. the batts it uses havnt gotten the best of reviews though. that kit is like 80 which comes with everything. i'll still be able to use dual coil cartos on it as well. hopeully work picks up and i get some nice commission so i can just buy a pre built mod 8]. would be nice to have reliability. im always afraid my home made mods will break when im away from a soldering iron and spare parts haha

 

[lynch]

Pretty sure you can also use that 4.8 volt battery in the maxi RS. I keep on saying I'm going to buy one of them but never do. I have my old buzz and a bunch of mods I did.

 

[captainbrianbeard]

im going to try using a 1.7 ohm carto at 3.7 volts. ive read reviews its as good as dual coils at 5. if its decent 3.7v mods are so much easier to build haha. whats your opinion on that? seems like less voltage and less resistance should get me a decent vape just like a high voltage and high resistance (the 3.2ohm coils in the dual coil). not sure how the two 3.2 coils make 1.6 but hey LR cartos are $1.50 its worth a shot

 

[lynch]

I havent tried the 1.7 carto just the DC carto and clearomizers. I tell you one thing I built a 6 volt mod using 2 lifep04 3v bats for 6 v and it's hard to go back to 3.7, for me impossible. Madvapes has a c- battery box and I got some 18650 battery holders off ebay for cheap that fits 2 3v bats perfect .The only problem is you need a spare set of those bats because I only get 3 hours tops out of them, but thats using a DC carto. bats charge very quick, they take a special charger.

 

[CraigHB]

Yes, the unregulated mods easiest to build. Though, regulated mods are great because you have much more precise control over vaping power. You can do limited adjustment with an unregulated mod by changing resistance, but it's usually just LR or SR, not many steps inbetween. Also, I really like how a regulated mod eliminates battery fade. That's a biggie for me.

My opinion about regulated mods is if you want something cheap and easy to build with the widest voltage range and highest output power, go with dual series cells and a buck converter.

If you want on-board USB charging, go with a single cell and a boost converter, but you give up some voltage range and possibly some output power. You also need a high drain battery for boost. A regular protected 18650 is usually okay, but for something smaller, you're limited to an IMR 14500. 10440s are out of the question. Kind of a lot to trade off just for on-board USB charging, but if you really want it, or you want to use a non-removable cell (typically a LiPo flat cell), that's the simplest option.

It's possible to charge series packs without cell removal, but the best way to go with that is a balancing charger which requires a special connector on the mod. Pretty much exactly the way the RC hobbyists do it. Series packs pretty much eliminate to possibility for USB charging, but there is a way to do it with some electrical gyrations. So far I haven't seen anyone do it, and I have no interest myself since I've only been building single cell boosters.

You mentioned your dad is an EE so if he's willing to help you design and build a converter, I'd go with the Linear LTC3785 or the TI TPS43000 controller. The LTC3785 is really trick because it switches between buck and boost on the fly, perfect for a single cell, but it uses a couple extra MOSFETs so it's going to be a bigger part. I've been using the TI controller myself. It's a multi-topology controller so you can do either boost or buck with it. The TSP43000 can also do SEPIC, but I'd recommend against that one. It's advantageous because it can go both above and below input voltage. I tried one and couldn't get very good efficiency out of it so I finally gave up. Those SEPICs are a real ..... to design and stabilize. Though, if your dad is a better engineer than I and he's willing to have a go with it, he may be able to make it worthwhile.