Need help with cut off voltage

[Yourdog]

Hi all, I am in the process of making a wood box mod, and I need a little help with making some kind of cut off/LED light show me when my voltage is too low, say I have 2 18650 batteries running in series in my mod, since they are 3.7 volts each and I heard its not good to let them get really low (below 3.2v each), I would like to make something that either turns off all supply at 6.4 volts, or the LED only to come on at the 6.4 volts. I have very little experience with circuit boards, and want to rig something up really cheap and easy.. does it exist?

Oh and btw if anyone was curious I am using a UCC383T-5 regulator for the voltage to get it down to 5v.

 

[trevor148]

If you want to keep it simple why not a voltage indicator connected to the battery. That way you would know the voltage the whole time your vaping the device.

here is a simple voltage indicator

 

[Yourdog]

Well, I don't have a lot of room, and I really like the way all wood looks, thanks for the suggestion tho.. You have any other ideas?

 

[retird]

What you are wanting is neither cheaper nor easier than what trevor148 suggested.....and designing the circuit choices you want is probably above your knowledge level, not to mention the space needed to install it in your wood mod....148's suggestion has merit IMO...

Note: A circuit that monitors the voltage and either shuts off the power or turns on an LED at a specific voltage level is not a simple circuit.....

And Breaktru gave you a circuit design in your other thread where you asked basically the same as in this thread...it gave detailed instructions on changing resistors to use 7.4 volt source (2-18650 in series).

http://electronics-diy.com/lipoly-low-battery-indicator.php

 

[Yourdog]

Aw well, that sucks this is my first wood mod, but maybe I will build one in the future and have some more room to make that circuit, I don't usually care how hard it is I like to learn Thanks for the suggestions

 

[retird]

Good luck...and I added breaktru's link in my previous post......

 

[Yourdog]

Oh man, you are right, I didn't read enough... when I saw that it said it was for a 9 volt system, I stopped reading... Thanks again, and thank you breaktru(I'm sorry I didn't read enough), that looks like it will do

 

[DrMA]

You can't get anything simpler or cheaper than what the guys suggested above.

But there is a comparable option that I've been considering for one of my mods: a multi-LED driver & voltage comparator like the LM3914 or TLC5960. But, like retird was saying, this is neither simple nor small.

 

[breaktru]

Oh man, you are right, I didn't read enough... when I saw that it said it was for a 9 volt system, I stopped reading... Thanks again, and thank you breaktru(I'm sorry I didn't read enough), that looks like it will do

No problema!
That circuit can be tuned for any voltage and the parts are small and can be squeezed into a tight mod.