Introduction

Electronic cigarettes (ECs) are battery operated devices that vaporize

a liquid solution typically containing nicotine, flavorings and inert

ingredients. The battery provides the energy necessary to vaporize

the solution and on/off control. The first generation of ECs had small

batteries (~350 mAh) and were actuated by a sensor in the cartomizer/

mouth piece. Second generation EC batteries offered user controls

such as push button “on/off” switch and selectable voltage control.

Third generation batteries tend to be very simple or very complicated.

with nothing but an “on/off” button or user controls that regulate by

voltage, power or even temperature. Some third generation batteries

have touch screen controls.

.

Most consumer products consisting of a lithium-ion battery are

required to abide to certain standards. National Electrical

Manufacturers Association (NEMA) provides safety standards for

portable, rechargeable cells and batteries, found under C18.2M: Part

2. Underwriters Laboratories also provide safety standard for lithium

batteries under UL 1642. These standards include testing for external

short circuit, over-charge, over-discharge, over-heating, temperature

cycling, shock etc. Since the “Battery” of an EC is part of a system

and not a stand alone product it is not subject to these stringent tests.

Ironically, only the high powered 3rd Gen ECs use batteries subject to

rigorous testing and approval,

typically the 18650 and 26650.

In this study we evaluated a range of second generation batteries for

voltage accuracy and power delivery using a simulated puff technique

as described below.

Methods and Materials Batteries were evaluated for accuracy regarding:

- Voltage under no load (not connected to an atomizer)

- Voltage under load (connected to an atomizer with simulated puff)

- Current under load (connected to atomizer with simulated puff)

Batteries Tested were new and unused, most were borrowed from local

vapor shops, some were from the researcher’s supply.

510 hubs were modified to allow the various measurements using a

Fluke-289 precision Multimeter. All measurements were conducted

in quadruplicate and randomized using a Latin Square design such

that each dial setting was independently set for each measurement

and was completely independent from other replicates.

Simulated puffs were conducted using a KangerTech EMOW atomizer

connected to a sampling pump (20 mL per second) using a zero

nicotine butterscotch e-liquid.

Voltage under load and current draw was evaluated using two

different atomizer resistances (1.5 and 1.8 Ohm)

Batteries Tested - EMOW, Itazte VV, Tesla, Aspire, Vision

Spinner 2, eGO Winder VV

Real World Evaluation of Second Generation

Electronic Cigarette Batteries Subekchhya Aryal, Evan Floyd, David Johnson

Department of Occupational and Environmental Health, College of Public Health,

The University of Oklahoma Health Sciences Center

Results

Conclusions

Though EC batteries are not directly covered by the

NEMA or UL standards, they were found to be accurate in

delivering the indicated voltage when not under load.

When under load, the batteries could not maintain the set

point voltage and appeared to reach a power plateau. This

was suspected to be caused by poor quality batteries with

high internal resistance, but the data presented here does

not support this initial hypothesis.

EC batteries should be subjected to consumer project

safety and quality standards as if the battery were a stand-

alone battery product

Acknowledgments Funding for this project was provided by Oklahoma Tobacco

Settlement Endowment Trust (TSET) through the Oklahoma

Tobacco Research Center (OTRC) Summer scholars program

For further information Please contact Evan-Floyd@ouhsc.edu for more information on

this and related projects.

Fig. 5 - Voltage supplied by the batteries drops off when under load. The

batteries are unable to maintain the set voltage during simulated vaping

Fig. 3 - Voltage evaluation under no load compared to the indicated voltage

of the dial or the digital display. All devices are within 5% of each other and

the true value (solid black line). These devices are accurate

Voltage Accuracy - No Load Voltage Accuracy - Under Load

Figure 1

Illustration of the evolution of batteries in electronic cigarettes from 1st to 3rd generations.

Gizmodo.com vaporjoe.blogspot.com

1st Gen

2nd Gen 3rd Gen Regulated

Mechanical Mod Box Mod

A.)

Fig. 2 -

A.) Experimental setup used to measure actual

voltage versus voltage indicated. The 510 hub was

modified to connect directly to the Fluke-289

multimeter

B.) several 2nd generation batteries similar to those

evaluated for this project and some 510 hubs

before modification.

C.) Experimental setup used to measure voltage

(or current) while under load (simulated vaping).

Atomizer tank connected to sampling pump set to

20 mL/sec. Voltage across the atomizer is

measured OR current passing through the

atomizer is measured with the multimeter.

3

3.3

3.6

3.9

4.2

4.5

4.8

3.3 3.7 3.8 4.2 4.3 4.8

Measu

red V

olta

ge

Nominal Voltage

Vision Spinner II(n=16)

Aspire(n=5)

eGO Winder(n=17)

Tesla(n=8)

Itazte(n=17)

EMOW (N=16) volatge measurementswere available only at 3.7,4.3,4.8V

3

3.3

3.6

3.9

4.2

4.5

4.8

3 3.3 3.6 3.9 4.2 4.5 4.8 5.1

Measu

red V

olta

ge

Nominal Voltage

Vision Spinner II(n=16)

Aspire(n=5)

eGO Winder(n=17)

Tesla(n=8)

EMOW (n=16)

Itazte(n=17)

3

3.3

3.6

3.9

4.2

4.5

4.8

3 3.3 3.6 3.9 4.2 4.5 4.8

Measu

red V

olta

ge

Nominal Voltage

Vision Spinner II(n=16)

Aspire(n=5)

eGO Winder(n=17)

Tesla(n=8)

EMOW (n=16)

Itazte(n=17)

Fig. 4 - Voltage evaluation under no load, the Bar graphs allow

easier comparison across batteries at the same set voltages.

Overall, device accuracy is within 5% of set point.

5

6

7

8

9

10

11

12

13

14

15

16

5 6 7 8 9 10 11 12 13 14 15 16

Measu

red P

ow

er

(Wa

tts,

P=

IR)

Expected Power (Watts, P=V2/R)

Atomizer Power - Under Load

eGo Winder VV

Vision Spinner 2

Aspire

Tesla

Itazte VV

EMOW

Fig. 6 - Combining measured voltage and amperage while under load we can compare the actual power to

the Expected power (solid black line). Substantial deviation is seen with maximum measured power

betweeen 7.5 and 10 Watts, depending on model.

Internal Resistance (w/ 1.5 ohm)

3.3 3.7 3.8 4.2 4.3 4.8

eGO Winder

VV 0.13 0.13 0.36 0.61

Vision

Spinner II 0.10 0.09 0.24 0.46

Aspire 0.11 0.15 0.39 0.65

Tesla 0.09 0.10 0.28 0.48

Itazte VV 0.15 0.16 0.32 0.51

EMOW 0.13 0.29 0.46

Internal resistance: 𝑅𝑖𝑛𝑡𝑒𝑟𝑛𝑎𝑙 = 𝑉𝑛𝑜 𝑙𝑜𝑎𝑑

𝐼𝑙𝑜𝑎𝑑− 𝑅𝑒𝑥𝑡𝑒𝑟𝑛𝑎𝑙

Internal Resistance (w/ 1.8 ohm)

3.3 3.7 3.8 4.2 4.3 4.8

eGO

Winder VV 0.11 0.13 0.24 0.44

Vision

Spinner II 0.09 0.08 0.14 0.30

Aspire 0.08 0.09 0.25 0.48

Tesla 0.10 0.11 0.13 0.33

Itazte VV 0.09 0.11 0.16 0.38

EMOW 0.11 0.14 0.31

Fig. 7 - Test for internal resistance indicated that internal resistance was not responsible for battery underperformance. At lower voltages,

the internal resistance is consistent between atomizer conditions (1.5 Ohm vs 1.8 Ohm). At higher voltages (4.3 and 4.8) the

measurement of internal resistance begins to more elevate as a total power of ~10 Watts. This is more indicative of an internal limiter

(circuit) than Internal resistance of the battery.

B.)

C.)