Planning first MOD build, Help me dot my I's and cross my T's

[trpxcst]

Hey all,

I've only been vaping for a short period of time (read: 1.5 weeks) but I haven't had a cigarette, or a craving for one since. I picked up a KGO kit and as a starter it is great. My main problem with it is that I really like to tinker and fiddle with things, and now that I know vaping is going to work and keep me from smoking, the urges to start tinkering are building.

I have been putting together a tentative list of materials for my first build, and would really appreciate it if y'all would take a look at everything and make sure I am on the right track, and haven"t left anything out. Also, if you have any other suggestions, I will happily consider those as well.

I want to build myself a tiny little box mod. Madvapes sells a plastic project box that is roughly 2"x1.4"x.75" I think this is the perfect size for a tiny box mod. From them I was also planning on grabbing one of their little 6mm tact switches, and a prewired 510 connector (mainly because I feel like being lazy-it is worth a dollar to me to already have that soldered). That pretty much covers everything you will see from the outside (I have a couple of little slide switches already in my box of random electronic bits).

Internally, I wanted to fit as much battery capacity as possible, and also integrate a charging circuit, so I can essentially build the thing and leave it together. I stumbled upon these batteries a while ago when looking for some more batteries for one of my r/c helis. Turnigy Nano-Tech Now that I am looking to build a new battery powered device they look like a pretty viable option. They are LiCo batteries, with more than sufficient discharge rating for an atty or carto's needs. The power density on them is also incredible.

The charging circuit is where I run into a bit of a problem. There are 3 pre-made boards that I have seen that will appear to work, but I'd really appreciate your input.

A) Generic ebay board: The price is nice on this one, also it has built in overcharge protection and the default charge rate of 400mA will mean not much downtime on a dead battery, and has 2 color leds to show charging and full. The downsides are that it is not specified if this carries any sort of monitoring for undervolt/undercharge situations, so I would likely need to add an extra protection circuit. also, the battery and all other electrics have to be soldered to the board.

B) Adafruit LiPoly Charger: A little more expensive, but looks really nice. The chip in this one supports both under and over charge protection. It has lights for usb power, charging, and complete. It also has pre-attached JST connectors for the battery, and another one for load/system out so changing out parts in the future would be easy if necessary. The big downside to this one appears to be that it is 1.4"x1.4" which means that it probably won't fit in my desired enclosure, and it doesn't appear that much could be trimmed off the edges to make it fit.

C) SparkFun LiPoly Charger The most expensive of the 3 (and the shipping is aweful - $12.50 is the lowest I have found). It appears to have all of the features of the adafruit, except the 3 separate leds, and is a size that I know will fit in the enclosure from Madvapes.

I was also debating on whether I should just purchase a small LiPoly protection circuit and put it between the battery and the charger regardless of which I choose even though the chips in the more expensive ones claim to be have undercharge protection. I'd imagine that someone here could point me in the direction of something that would still fit in the space available to me.

But assuming that this all looks good to you guys, I am excited for what this could be. A tiny box mod with 750 mAh of power and an integrated charging circuit.

Sorry for getting so long winded. I really look forward to your responses, as I have been reading these pages for days, and trust all of your advice. And like I said earlier, if anyone out there has other suggestions, pleas let me know.

Thanks -

 

[asdaq]

That tact switch is rated at 50mA, better avoid using it, unless you use a MOSFET with it.

The battery is at the other end of the extreme, 35-70C is a lot for e-cig use and for 750mAh it is not all that compact either, especially when paired with the onboard charger.

A tiny box mod with 750 mAh of power and an integrated charging circuit.

with this as the goal, you could easily get a 2AA box, make something like the nicostick, and have room in it for a usb charging circuit, or since you have kgo charger, just add a charging port to the mod and use that charger.

I don't want to stifle your plans, but consider this just getting that 1st mod under your belt and go from there. I do want to stifle your plans with that switch though, most certainly.

 

[trpxcst]

I totally understand the concern about the switch. I like the look and size of that switch, but I can't seem to be able to find something similar in a higher rating. I was just going to use something different, but had read in other threads that many people have used that switch with "good results", so I was thinking I would just give it a try.

Then in my reading of the modders section, I stumbled upon Raidy's thread "all my mods part1". I have been working my way through reading that entire thing when I have time (so far I have made it to page 155), and in an early post of his, he put up a diagram of a small circuit that uses a couple of resistors and an IRL3013 mosfet to act sort of like using a low current switch to trigger a high current relay like they do in automotive applications regularly. Raidy's post

I do plan on making a nicostick - going to "accidentally" build it with a 901 connector, that way I have an excuse to give to the wife when I "all of a sudden" need to buy more kit. I also have looked at the lighter mod, and plan on trying to make it into a supermini bottom feeder. I completely get the "get the first one done, then move on" but for me, I want the first one to be "special". Not that any of the others aren't, but I get sentimental about weird stuff sometimes.

In this post I was mainly looking for help deciding on a charging board, and advice on whether I should add a protection circuit between the battery and charger. But thank you for your concern asdaq, I have read many of your posts, admire your work, and value your opinions.

 

[Algernon]

The ebay board was listed with a 4.2v charged voltage, so it does have overvoltage protection as 4.2 is the maximum charging voltage for 3.7v lithium-ion batteries and it stops there.

Also, as you can see, it's the same board JJ used in his cell-phone battery mod. https://dl.dropbox.com/u/77813682/Osat1.jpg

 

[mphsjeep]

Go for it man. skip and build yourself a nice 5 volt box mod. All parts from MadVapes. See attached....

I know the rating of the tactile switch you want to use is iffy but I use them directly wired to a 5v and a 6V mod and they push just fine.....good luck!!