Battery Voltages -- Surprise!

[g123456e]

Scottbee,

Thanks for all of your hard work! I have read the "Dream PV's" thread and don't understand how modding/adding a liquid reservoir to the Tornado/Ego makes for a more potent battery. Could you explain?

Also, I have read this thread a couple of times and am considering purchasing a GG slim or similar device that uses a 10440 battery. I have seen it mentioned here but don't see that it was tested? Will that battery produce true 3.7 volts? I know it won't last as long as a 14500 because of the lower Mah. Thanks again!

 

[Nietzsc]

a 10440 would be a "natural" step, but eventually you would want to move to a higher mah battery. I have a mini mag mod and about to start my laser pointer mod, they both use 10440's, but I'm already getting tired of the 10440's and thinking on moving to a bigger mod.

About voltage:

you would notice that the tests were run on regular batteries, cause the suspects of lowering voltage were the mosfets or electronic circuits on them.
As far as I know commercial mods generally dont deal with any electronics in them, they are just a battery through a switch and then atty.

 

[g123456e]

a 10440 would be a "natural" step, but eventually you would want to move to a higher mah battery. I have a mini mag mod and about to start my laser pointer mod, they both use 10440's, but I'm already getting tired of the 10440's and thinking on moving to a bigger mod.

About voltage:

you would notice that the tests were run on regular batteries, cause the suspects of lowering voltage were the mosfets or electronic circuits on them.
As far as I know commercial mods generally dont deal with any electronics in them, they are just a battery through a switch and then atty.

Nietzsc,

Are you ready to move on to a bigger mod because of the battery life or the performance of the 10440? I actually have a box mod that uses a 14500 battery so I know how 3.7 volts perform and can deal with the 10440 lasting 1/2 as long as the 14500 if it performs at true 3.7 volts. I wanted something stainless that would last but not be so large. I used to smoke Capri super slims so everything I am using seems huge. hehe

 

[Nietzsc]

Nietzsc,

Are you ready to move on to a bigger mod because of the battery life or the performance of the 10440? I actually have a box mod that uses a 14500 battery so I know how 3.7 volts perform and can deal with the 10440 lasting 1/2 as long as the 14500 if it performs at true 3.7 volts. I wanted something stainless that would last but not be so large. I used to smoke Capri super slims so everything I am using seems huge. hehe

I am ready!!! well... at least until I have the money to buy one

My guess is that the GG will deliver true 3.7 volts, but I'm also looking forward to build a tester like the one made by scottbee just to test stuff.

I also think that vendors should include this information on their products specs, cause you can only test a mod until is in your hands, don't you?

 

[voltaire]

I am ready!!! well... at least until I have the money to buy one

My guess is that the GG will deliver true 3.7 volts, but I'm also looking forward to build a tester like the one made by scottbee just to test stuff.

I also think that vendors should include this information on their products specs, cause you can only test a mod until is in your hands, don't you?

I would personally recommend against the 10440, they just don't last. A KR8 XL battery lasts longer, a regular KR8 lasts about the same. The mAh rating on them is usually a gross exaggeration. If you don't mind length, you could get one of those GG SuperSlims (I think that's what they're called, from memory) that use TWO 10440's - then you would get decent battery life.

 

[indyxlt]

I must echo the praise of everyone else that's posted here; Great job Scottbee and thanks for sharing and educating.

 

[Scottbee]

It was/is my pleasure.

Although it is just a little bit off topic.... I thought I'd throw in a little blurb regarding the intrinsic over-current protection on the Tornado/Ego line of batteries.

There is none.

Please keep that in mind when playing with these batteries, trying out very low resistance atomizers, or maybe messing with cartomizers and atomizers that may have internal shorts or other problems.

When a Tornado/Ego is presented with a situation where it is asked to deliver a bit over 3A (three amps), there is no mechanism that will protect the battery or the controlling circuitry from this excess demand. The good news is that the battery will most likely not explode or catch fire or anything horrific like that. The bad news is that the output MOSFET simply isn't designed to handle that much current.. and it will die a painful death.

There are at least two pronounced failure modes (and probably more). In one case the unit will simply quit delivering power to the atty connector, even though the button still works and the LED will illuminate. In the other mode, the output MOSFET will "latch" on and the battery will deliver power to the connector, even if the button is not pressed (and the LED is not illuminated).

Should this happen.. well.. you're screwed. There is nothing that you can do externally to the battery unit to "repair" it.. and most don't have the tools/capability of taking them apart and repairing them. Sorry... and I'm just the messenger.

 

[rasci2]

Scottbee

Are you saying that if a connect a LR atty like those sold by NHALER that I will burn out and ego or 510 battery?

 

[Scottbee]

Scottbee

Are you saying that if a connect a LR atty like those sold by NHALER that I will burn out and ego or 510 battery?

Naw. When a LR atty is put on a Tornado/eGo battery it ends up drawing about 2A.. which is still in the "safe range".

But you can run into problems when a atomizer or cartomizer "goes bad", or for some other reason drops below about 1Ω.

 

[RockClimb]

The test rig: The test rig for my analysis is nothing more than a quality DVM and a fixed resistance load for the batteries. In this case, I am using some nice stable wire-wound resistor that create a 2.5 Ohm load.... roughly the same load as a typical 510 atomizer.

I am glad I found this thread, and that you did a load test with a quality DVM! I had been thinking about doing what you did. Glad I did one last search in the forum..... saved me a lot of work.

 

[MalabarFront]

There are at least two pronounced failure modes (and probably more). In one case the unit will simply quit delivering power to the atty connector, even though the button still works and the LED will illuminate.

I've discovered that if you drop it enough times you can get the same symptom as well. Very frustrating to see the light come on but no vapor get produced.

 

[robl45]

so will the trustfire batteries put out true 3.7volts? can I use those in a nicostick type device?

 

[ShaneC]

So what about the 1.5ohm atty's on the stock batts?

That'd be around 6.4W or so based on the 3.1V readings you took initially.

Though I wonder if that's a bit too much heat for the atty?

 

[greenie]

Good information scottbee. It explains a lot. Although I really like the 510 atty the standard 510 battery is short on life. That is just personal since I sit here and chain vape. I drain the power out of these batteries to quick so that I am not getting any vapor. I too thought it was my atty getting dirty.

I think the 801 batteries work well with the 510 atty. I am going to see how a 901 battery performs with them and after reading your post I will defiantly try the 808 battery.

 

[DaveP]

If the voltage drop across the 2.5 ohm atty were 0, the theoretical current (I) should be 1.48 amps (I=E/R). The power (wattage) using such a battery would be 5.476 watts (P=EI). That would occur with a power source capable of delivering full voltage across a 2.5 ohm load, which is close to a dead short.

Using the actual voltages that you measured, the current is 1.24 amps across the load and 3.844 watts of power produced. So, the power loss is about 30% with a .6v drop in battery voltage.

(100-(3.844/5.476))=30

In other words, the small standard battery can produce only 70% of the wattage that a battery that operates with no (or minimal) voltage drop could deliver. That's significant.

You have proven that tiny batteries can't deliver the current necessary to produce enough wattage. Wattage is a measure of power produced by a given voltage across a given load. In this case the load is the atty resistance and the power is lost through the inability of the small battery to deliver current when loaded down by the low resistance atty. This is demonstrated by the use of larger batteries.

I was surprised by the USB pass through measurements. The USB PT has a larger battery and can also be used offline until the battery goes dead and has to be recharged using the USB port. Too bad the larger battery doesn't deliver greater loaded voltages.

Great work!

 

[DaveP]

As I've mentioned a number of times.. the "unloaded" peak surface charge voltages of these cells is almost a useless number. I can tweak that number all over the map just by changing the charge algorithm.

Put them on a load and then read the voltage. That is telling you something.

Exactly! Try using 8 "D" flashlight cells in series to jump your car off... 12v is not always 12v. The amp/hour capacity is key. Now, OTOH, 3 of those 1.5v nicads in series should produce volumes of vapor from an E-cig with little voltage drop.

 

[DaveP]

The amount of heat a device can produce is determined by the amount of
energy it receives, which is wattage, not voltage. So why the amazement that a lower voltage device can produce more heat? If one atty cn produce more heat than another, then it's either more efficient at converting electricity to heat, or it's receiving a higher wattage feed, or it's simply larger and drawing more power than the other does from the battery. An elctrical source only provides the amount of power a device asks for.

Power = E*2/R (voltage squared/resistance)

The reason a device only draws the power it needs is due to the resistance of the power input of the device. This can be affected by voltage regulators, zener diodes, etc, but a device will draw power from the source in a direct correlation to the resistance it presents to a DC power source.

If your atty measures 2.5 ohms and you give it 3.1 volts, the current (power) drawn which is represented as heat in the atty, will be 3.844 watts.

If the battery can deliver 3.9v the power will be 6.084 watts. Thus, .8vdc increased almost doubles the wattage (heat) and you get much better vaporization. There's some non-linearity in the curve if it were plotted due to the squared voltage value divided by the resistance.

My 510 atomizers measure 2.2 ohms. Actually the measured resistance is 2.5 ohms, but I get .3 ohms with shorted leads, so you have to subtract that from the resultant reading on the meter. My "real" Fluke meter reads similarly to my Chinese knockoff Fluke look alike meter once the correction for lead resistance is subtracted.

 

[Whistle_Pig]

If the voltage drop across the 2.5 ohm atty were 0, the theoretical current (I) should be 1.48 amps (I=E/R).

If the voltage is 0, then no current is flowing at all.

 

[DaveP]

If the voltage is 0, then no current is flowing at all.

LOL, you are right. What I meant to say is that if the battery voltage didn't drop when loaded with the atomizer coil, then the current should be X. If the atty loads the battery past it's point of providing a constant voltage, all bets are off unless you use Scotbee's method of measuring under load.

We all thought our batteries were providing 3.7 to the atty. Scotbee proved that wrong. They are obviously voltage or current regulated to lengthen battery charge life.

 

[5cardstud]

This is the reason I use adjustable voltage to vape.