Electricity and USB questions

I'm a bit confused and I know there's a few members here that are rather knowledgeable with electricity fundamentals.
I have 2 USB driven 'pass-thru' 510s.
(a)One is the "5 volt" version which is taking power from a 2.0 hub, sending direct current, and giving just under 5 volts directly (I assume) to the atty connection.
(b)One is the doing essentially the same thing, but has a battery box with a 10440 3.7 volt battery inline between the USB and the atty connection.

What I'm having trouble grasping is why when model b takes 5 volts from the usb and sends it to the battery, there isn't an issue. It works as a pass thru and as a portable unit. But both ways operating at 3.7 (4.195 to be more correct) volts. I understand when I take it portably, since there is only the battery there. So is the battery basically acting as a resistor or a limiter when plugged in?

If so, the point of my questioning is could I 'charge' and pass-thru a CR123 in the same sense? For example, if i wanted to make, I guess a box mod, could I add a mini usb port so I could just charge my CR123 without ever having to take it out of the mod?

It seems so. Unless I'm missing something else going on.

(for clarification) The cr123 is 3.7 volts and it would only be one.
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Yellow,
well to start I hope you are not using eiher with your laptops usb port!
You can charge some batts with USB, still I would never recommend to using your laptop for anything like that. Unless you dont care about possible expensive damage all this could cause.
The output on your standard 2.0 usb is 5V and 500mah.
Yes it is possible and there is a few home made mods out there that charge their internall batts thru USB.
If you really want the usb PT and a portable corded solution just try usung your batterless 5vPT with a battery pack...
Alot of stuff here to explain, so feel free to come back and We'll start breaking it all down

 

I'm here! haha. Ok thanks for the numbers on mah for a pc's port. I'm not using a laptop.
I think I might have mislead what I'm trying to achieve based on some of your response.
I'd like to have a 3.7 volt mod (regardless of box or even inside a coke can).
The best battery I could find that is very small is an AW - ICR123. It has multiple protection circuits from what I remember finding when I was researching.
Anyway, it is 750mah. Should be precise on that too.

I'm not necessarily trying to build a pass-thru, only something portable (box mod for instance) that I can technically charge by having a usb connection.
And since it would be able to charge like that, then it would actually work as a pass-thru in the same instance. Killing like 3 birds with one mod....?
Now, the mah gets me lost, but on the standard 510 pass-thru that you can buy on any site, I can actually use on non 2.0usb. i can use it on standard .5amp wall plugs and car chargers (with usb ports of course). Now, the 5 volt, can't do that. It will just not work at all or the led flashes telling me I suck. So since I'm going the 3.7 volt route, other than mah, I don't see any issues. BUT, before I start frying my computer or just wiring, I guess input is needed.

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Just wanted to add that the wall charger that was recommended to charge these batteries (basically any cr123s too) meters out to 5.05 volts output. Also, 350 mah. So, it basically is the same thing as a 2.0 usb hub other than there's a protection circuit inside....which I wouldn't want to implement into my mods.

 

What charger was recommended? lol
Ok since I guess I got pretty confused on what yo wanted to make a first....
So my understanding now is that you want to make something ہ la bartleby?

 

Ultrafire WF-138 charges 3.0 and 3.6 volt batteries. I don't think it was necessarily recommended but somehow I read enough to make a conscientious decision to buy it?

Anyway, I guess a Bartleby is the theory...although I can't find the build thread and only Mooby's review on it, which never shows technical details on how to make the mod.

Halfway through the video, "...uses a 14500 900mah 3.7...".
So, it is charging a 900mah bat?! That means I can do that with my 750 mah.
Now to find this hidden build thread....


Oh, just for the record, I'm not trying to build a box mod. Just a portable storage unit with all functionality. I want to grab something that has juice in it, an atomizer already attached, a battery loaded, and then use it however I want. What I dislike about every mod and box mod especially is that i can't put it in my pocket without worrying about breaking the atomizer or flexing the connection at the least. The solution to that: take the atty off every time you put in in your pocket and put it back on when you're ready to vape.

No. I will not.

But, the problem for me in making a 'complete' portable vaping machine is space. So I need a CR123 for size. But the other problem is disassembly (to charge the battery). I can make any mod that while forever hide the battery. It still can be removed, but not without going through shit. So, I want to be able to charge it inside the mod so I don't have to take it in andout every day.

A better description of what I want is a Mr. Puffer with Bartleby charging and PT feature, BUT, all enclosed, including the atty. Then when you open it, a contact turns activates potential power (thereby not having to worry about a switch turning your atty on while its in your pocket). Then you use your switch to vape.

 

I've got a lot of reading to do on ECF....not where I want to play. I'm seeing basically the same thing that's inside of a 510 PCC is what modders are using to charge batteries. The only problem is I don't know if I can just take the leads off whatever battery is inside of there and go to my battery. I guess I could try.