There was a big empty space in there... but those 14500's last soooo long I thought it would be nice to have an idea where the charge is.
(this one has a 510 atomizer mounted, by the way... I like it)
As for a how to - it's simple but requires some work.
All LED's have a "turn on" voltage. You can measure it with most multimeters with a diode setting. Or you can rig up an LM317 with a pot and slowly creep up to the voltage until it turns on.
Then make a row of LED's and create a voltage divider with a couple resistors that makes exactly that voltage at each point you want to monitor.
Using small clear red LEDs like this you can easily get away with a 1K + x dividers. The entire string lit up full bright on a brand new battery draws only 9mA.
That's .009 amps. The atomizer draws about 1.5 amps. Wired to the push switch, it has no effect on battery life whatsoever.
On this one, the first
LED starts dim at 3v, and is full bright at 3.3 volts.
The next is dim at 3.3 and is full bright at 3.6 volts.
The next is dim at 3.6 and is full bright at 3.8 volts.
the last is dim at 3.8 and is full bright at 4 volts.
When the battery is full, all four are on bright. When it's dead, only the bottom one lights up. I chose 4, since all four LED's, from dim to bright, overlap slightly into the range of the next one, so it's a full scale. You can tell whatever volts it is very accurately - not just the 4 points.
Now the big bonus -
The worst thing about batteries, is at any random time in their life, they can still charge up full and appear to be good, but just start to work BADLY. This is internal resistance. It can happen overnight, or over time.
When you put a load on a good battery, the voltage should stay within a couple points.
A bad one will drop really fast, right down to 3.3v on a fresh charge, or even 3v and below.
With the onboard volt display, now I can see the voltage on the battery WHEN I am vaping on it. Any crappy batteries will show up right away because the LEDS willl taper down to dead very visually while you drag on it.
Plus I don't have to guess all day how full the battery is
A quick twist of the atomizer, push the button, and you can see the volts of the battery without a load on it too, or test the ones in your pocket in 2 seconds.
(this one has a 510 atomizer mounted, by the way... I like it)
As for a how to - it's simple but requires some work.
All LED's have a "turn on" voltage. You can measure it with most multimeters with a diode setting. Or you can rig up an LM317 with a pot and slowly creep up to the voltage until it turns on.
Then make a row of LED's and create a voltage divider with a couple resistors that makes exactly that voltage at each point you want to monitor.
Using small clear red LEDs like this you can easily get away with a 1K + x dividers. The entire string lit up full bright on a brand new battery draws only 9mA.
That's .009 amps. The atomizer draws about 1.5 amps. Wired to the push switch, it has no effect on battery life whatsoever.
On this one, the first
LED starts dim at 3v, and is full bright at 3.3 volts.
The next is dim at 3.3 and is full bright at 3.6 volts.
The next is dim at 3.6 and is full bright at 3.8 volts.
the last is dim at 3.8 and is full bright at 4 volts.
When the battery is full, all four are on bright. When it's dead, only the bottom one lights up. I chose 4, since all four LED's, from dim to bright, overlap slightly into the range of the next one, so it's a full scale. You can tell whatever volts it is very accurately - not just the 4 points.
Now the big bonus -
The worst thing about batteries, is at any random time in their life, they can still charge up full and appear to be good, but just start to work BADLY. This is internal resistance. It can happen overnight, or over time.
When you put a load on a good battery, the voltage should stay within a couple points.
A bad one will drop really fast, right down to 3.3v on a fresh charge, or even 3v and below.
With the onboard volt display, now I can see the voltage on the battery WHEN I am vaping on it. Any crappy batteries will show up right away because the LEDS willl taper down to dead very visually while you drag on it.
Plus I don't have to guess all day how full the battery is
A quick twist of the atomizer, push the button, and you can see the volts of the battery without a load on it too, or test the ones in your pocket in 2 seconds.
