Real vs. advertised Capacity and Capacity Fade in Lithium Ion 18650 Batteries

School Name

Center for Advanced Technical Studies

Grade Level

12th Grade

Presentation Topic

Physics

Presentation Type

Non-Mentored

Abstract

For this research project, the purpose is to find if there is any difference between the milliamp hour rating labeled on the battery compared to discharging the battery and calculating the milliamp hour spent during a 0.5C rate discharge (for Imax B6 Mini); along with measuring capacity fade and temperature of chinese made 18650 lithium batteries. Lithium ion batteries are important since the batteries are used with electric vehicles. Fossil fuel availability is declining for the transportation industry and a need for new transportation independent from fossil fuels is vital. If lithium ion 18650 batteries are discharged experiencing high temperatures and a high C rate, then the battery will be more susceptible to thermal runaway and will show a more significant capacity fade. A 0.5C rate discharge for the 18650 batteries used equates to discharging the battery with a current of 1.3 amps because the milliamp hour rating for all 18650 batteries in the project are rated 2600 milliamp hours. The battery is then discharged to its specified end voltage depending on the number labeled on the battery. The mAh at the end of the discharge is divided by the C rate to calculate actual mAh. The two total mAh are converted to coulombs for comparison. To measure the capacity fade with the HP 34401A multimeter, each type of battery is tested by ending at different depth of discharge percentages and C rates. Then the data is graphed to show capacity variation. Olight(2) lost 4.7% capacity/ max temp. 45 Celsius, Nitecore(2) lost 8.5% capacity/ max temp. 47 Celsius, Ultrafire(2) lost 9.7% capacity/ max temp. 50 Celsius. Data from HP 34401A multimeter(0.8C rate avg.) Olight(4) lost 5.9%, Nitecore(4) lost 9.3%, and Ultrafire(4) lost 10.5% capacity after 5 discharge/charge cycles.

Location

Wall 307

Start Date

3-25-2017 12:15 PM

Presentation Format

Oral and Written

Group Project

No

COinS
 
Mar 25th, 12:15 PM

Real vs. advertised Capacity and Capacity Fade in Lithium Ion 18650 Batteries

Wall 307

For this research project, the purpose is to find if there is any difference between the milliamp hour rating labeled on the battery compared to discharging the battery and calculating the milliamp hour spent during a 0.5C rate discharge (for Imax B6 Mini); along with measuring capacity fade and temperature of chinese made 18650 lithium batteries. Lithium ion batteries are important since the batteries are used with electric vehicles. Fossil fuel availability is declining for the transportation industry and a need for new transportation independent from fossil fuels is vital. If lithium ion 18650 batteries are discharged experiencing high temperatures and a high C rate, then the battery will be more susceptible to thermal runaway and will show a more significant capacity fade. A 0.5C rate discharge for the 18650 batteries used equates to discharging the battery with a current of 1.3 amps because the milliamp hour rating for all 18650 batteries in the project are rated 2600 milliamp hours. The battery is then discharged to its specified end voltage depending on the number labeled on the battery. The mAh at the end of the discharge is divided by the C rate to calculate actual mAh. The two total mAh are converted to coulombs for comparison. To measure the capacity fade with the HP 34401A multimeter, each type of battery is tested by ending at different depth of discharge percentages and C rates. Then the data is graphed to show capacity variation. Olight(2) lost 4.7% capacity/ max temp. 45 Celsius, Nitecore(2) lost 8.5% capacity/ max temp. 47 Celsius, Ultrafire(2) lost 9.7% capacity/ max temp. 50 Celsius. Data from HP 34401A multimeter(0.8C rate avg.) Olight(4) lost 5.9%, Nitecore(4) lost 9.3%, and Ultrafire(4) lost 10.5% capacity after 5 discharge/charge cycles.