Battery Voltages -- Surprise!

[Nuck]

With fresh batteries measuring 4.20 volts unloaded I get 3.87 volts volts loaded with a 14500 and 3.94 with an 18650 (510 atty). I did checks with a 510 passthrough some time back. It drops around half a volt in the wires from the battery to the atty. I doubt if the FET is dropping a lot of voltage - I have used small FETs in a couple of my mods and measure the drop as 0.04 volts.

That's odd. I've been unable to find a 14500 that can properly push a 510. The voltage drop has always been substantial. I've even removed the battery protection pcb to take it out of the equation and always get the same results.

 

[Ralph Hilton]

I notice the 14500 drops off much faster than an 18650. Just checked one after 10 mins and its down to 3.5 loaded (3.8 unloaded)

 

[Scottbee]

Like I said, daniel, I just barely know my ... from a hole in the ground when it comes to this kind of thing I do have the 901/Kr8 to 510 adapter. It works great; BUT...I don't think I would try to use it to charge the Kr8 battery with a 510 charger. If Scottbee or someone else thinks different, they can certainly advise you better than me

I've charged my KR808D-1 batteries on a 510 charger using the adapter. It has worked, but I can't make any guarantees and your mileage may vary.

 

[Scottbee]

Scottbee, do you remember the source of the Kr8 bettery you used for testing?

The KR808D-1 batteries that I tested came from V4L and I got them a couple of months ago. I am hesitant to say that all Kangers from all sources will perform this same way (but I hope they do). I know that vendors and Kanger mess with their recipes.....

 

[Scottbee]

Now you got me thinking again. It seems that the PT is juicing the inline battery a bit. I wonder what loaded voltage you'll get out of the Bartleby when it is USB connected?

I ran this very same test last night. I got bout 3.95V out of it when it was connected to the USB powered hub with a "fully charged" battery.

I'm sure the relative health of the Bart 14500 battery will enter into this equation.

 

[Scottbee]

So anyone have any guesses why the Kanger batteries discharge is that much higher? Are they using standard Li-ion or a different chemistry?

Personally I think it has less to do with the battery and more to do with the switching circuitry used by the manufacturer. Don't get me wrong, small batteries have internal resistance and that causes them to "sag".... but as the battery size (mAh) increases, you would expect the internal resistance to decrease. So one would expect the Joye Mega and eGo to have less V-drop. And they don't.

 

[Scottbee]

I doubt if the FET is dropping a lot of voltage - I have used small FETs in a couple of my mods and measure the drop as 0.04 volts.

Certainly it is possible to have a FET switch design that has a very small V-drop. But I don't think Joye is doing this on the 510 batteries, eGo, or their PT. And I think it may be somewhat intentional.

 

[Scottbee]

That's odd. I've been unable to find a 14500 that can properly push a 510. The voltage drop has always been substantial. I've even removed the battery protection pcb to take it out of the equation and always get the same results.

Interesting. The Barts that I am playing with (loaners from Kent C) use the 14500 and I've been pretty impressed at how stable their voltages have been (within reason).

Of course... when it comes to voltage stability with time.. the bigger the battery the better. No argument.

 

[smok(ERF)]

It would be interesting to get values for Silver Bullet, BB, Chameleon (with and without extension) and some other solutions.

The german retailer of the Chameleon provided the following value for Chameleon 6V-extension (2x3V) kit: real voltage: 4,5V (801/V3 3,5 Ohm)

(Unfortunately I'm not allowed to post a link to the source, because I'm a new user with less than 15 posts.)

 

[eGeek]

Interesting. The Barts that I am playing with (loaners from Kent C) use the 14500 and I've been pretty impressed at how stable their voltages have been (within reason).

Of course... when it comes to voltage stability with time.. the bigger the battery the better. No argument.

Hi Scottbee, what batteries did you have in the Bart? I have been using AW 14500 and I do notice a difference between those and the Trustfire 14500 in the same unit. It may be negligible but it is there, slightly more of a 'kick' and for longer.

 

[Eep]

Wow, great information. Thanks for doing this!

 

[AlexTM]

The german retailer of the Chameleon provided the following value for Chameleon 6V-extension (2x3V) kit: real voltage: 4,5V (801/V3 3,5 Ohm)

(Unfortunately I'm not allowed to post a link to the source, because I'm a new user with less than 15 posts.)

Elektronisches Rauchen Forum - Akkuträger 6V Option: offene Fragen und Meinungen

 

[Ralph Hilton]

Certainly it is possible to have a FET switch design that has a very small V-drop. But I don't think Joye is doing this on the 510 batteries, eGo, or their PT. And I think it may be somewhat intentional.

It looks like you are right - I just measured one - the little board in the 510 passthrough drops 0.52 volts.

 

[Scottbee]

Hi Scottbee, what batteries did you have in the Bart? I have been using AW 14500 and I do notice a difference between those and the Trustfire 14500 in the same unit. It may be negligible but it is there, slightly more of a 'kick' and for longer.

The Bart that I have was/is a loaner (but I ordered my very own TODAY). It has a Trustfire 14500 in it.

I should note that this experiment was less of a test on the Bart (I figure we all have a decent idea of what kind of voltage we can get from a 14500 and the like) and more of an investigation of what we get from the "stock" batteries and a unit like the eGo. It was my surprise over the eGo output loaded voltage that ran me down this path. The Kanger voltages were the biggest surprise.

 

[Scottbee]

It looks like you are right - I just measured one - the little board in the 510 passthrough drops 0.52 volts.

Ralph,

That is an excellent data point! Thanks for taking the time to do that!

 

[Ralph Hilton]

I was thinking about it a bit more - the circuit is quite a bit more complex than just an FET as it is permits charging which couldn't be done with just an FET and contains whatever protection circuitry they chose to include. I'm guessing that its all these things together that add up to the half volt. It looks actually a bit of a lazy design on the pass through as the same board exactly is used as in the 510 batteries with the unnecessary voltage drop.

 

[Kelemvor]

why do you think its unnecessary for the manufacturer ? imho its well thought of doing so.
the circuit is optimized for the 2.2ohm joye atomizer.

 

[Scottbee]

I was thinking about it a bit more - the circuit is quite a bit more complex than just an FET as it is permits charging which couldn't be done with just an FET and contains whatever protection circuitry they chose to include. I'm guessing that its all these things together that add up to the half volt. It looks actually a bit of a lazy design on the pass through as the same board exactly is used as in the 510 batteries with the unnecessary voltage drop.

Ralph,

I was going to attribute it to "that's just the way it has to be if you want to be able to charge it through the atty connector" until I saw the Kanger results.

I have yet to pull the PCB and reverse-engineer it to see just exactly what they have done and why. Unless somebody beats me to it, I will ultimately get there.

But I'm hoping somebody beats me to it....

 

[Ryum]

Do you need an adaptor to run a Kr8 batt to a 510 atomizer? And if so, it would follow that a 510 charging device, such as say a PCC, would not fit the Kr8 batteries. Basically devices that charge 510 batteries would not charge Kr8 batteries. Am I correct with these assumptions?

Here is a quick list of adapters
5x 510-901 silver adapter(510 bat to 901 at) - E-cig Multi Adapters
1x 901-510 adapter(901/808D-1 bat to 510 at) - E-cig Multi Adapters
Adapters
901/510 adapter - $2.99 : Zen Cart!, The Art of E-commerce

 

[Ralph Hilton]

why do you think its unnecessary for the manufacturer ? imho its well thought of doing so.
the circuit is optimized for the 2.2ohm joye atomizer.

The thin passthrough wires drop an additional 0.4 volts