Determine battery state of charge using an open circuit voltage test.

Lesson Plan for

DIT 190-191

ELECTRICAL/ELECTRONIC SYSTEMS

Course HS Title: / Electrical/Electronic Systems / Program:
KCTCS Courses included in HS Title: (Lesson is prepared for course highlighted.)
KCTCS Course No. / KCTCS Course Title
DIT 190 / Electrical/Electronic Systems
Introduction/Context / This lesson will instruct the student on how to determine battery state of charge using an open circuit voltage test. Knowledge of these techniques and the skills required to correct problems associated with this task are necessary for a student to acquire if they wish to compete for high paying, high skilled jobs in a Diesel Repair Facility. Entry level technicians need to be able to perform this task to 100% accuracy. Incorrectly performing this task can lead to an accident or create customer satisfaction issues.
Prepared By / School / Date:
Grade Level / No. Students / No.IEP's: / Lesson Length:
Task
Determine battery state of charge using an open circuit voltage test.
Objective
Given the proper tools and instruction, the student will be able to determine battery state of charge using an open circuit voltage test, and pass a written test covering the task with 100% accuracy.

Connections:

Skills Standards:
OH 001
OH 002
OH 003
OD 002
OD 003
OD 005
New Common Core Standards:
RST 11-12 3
A-CED-4
N-Q.1
Common Core Technical Standards:
TD-OPS 2
TD-SYS 2
New Generation Science Standards:
HS-PS2-5.
HS-PS3-3.
HS-PS3-5.

INSTRUCTIONAL MATERIALS/TECHNOLOGY

Teacher Designed Materials and Other Handouts


Textbooks and Workbooks

Author / Title/ISBN No. / Edition / Publisher / Pages
Various / Electrical/Electronic Systems ASE Test Prep T6 / Fifth / Delmar / 19


Equipment

Quantity / Item / Source


Content/Presentation/Demonstration Outline

Inform students that a rough estimate of battery state of charge can be determined by measuring its open circuit voltage. With the battery under no load, tell them to measure voltage across the terminals. If it is 12.6 volts or more, it is considered fully charged. If the battery has been recently charged (whether inside or outside the vehicle), tell them to draw off the surface charge using this same method. Allow the battery to sit for 15 minutes before testing, then test the open circuit voltage. Let them know that any reading less than 12.6 volts indicates that the battery should be charged.
Instruct students that battery state of charge can also be determined by using a hydrometer. A specific gravity reading of 1.265 or higher at 800 F (26.6° C) indicates a fully charged battery. A severely discharged battery will show a reading of around 1.120 or so. A reading of 1.200 would indicate a battery that is 50 percent charged. Let them know that temperature corrections must be made to the readings for batteries not within 10° of 80°F (or between 21.1°C and 32.2° C).
Let students know that the battery state of charge can also be determined by an open circuit voltage (OCV) test across the battery terminals. When the OCV has stabilized, the following readings can be used:
• 12.6 volts or more Fully charged
• 12.4 volts 75% charged
• 12.2 volts 50% charged
• 12.0 volts 25% charged
• 11.7 volts or less Fully discharged


Applications/Practice

1 / Refer to content


Evaluation and feedback Prior to Testing or Lab Work

1 / Objective 1. / Formative assessment / Instructor will observe students as they practice the procedure to assure correct procedure and safety practices are being followed. A checklist will be utilized to chart student progress on the task. Questioning techniques will be utilized as necessary to demonstrate student comprehension / Adaptations and/or accommodations for special needs students will be added if required.


STUDENT ASSESSMENT:(Assess student progress with performance criteria.)

1 / Objective 1 / Summative assessment / written test questions on stated objective / adaptation and / or accommodations for special needs students will be added if required
IMPACT--Reflection/Analysis of Teaching and Learning: (How did students’ progress in relation to the state objectives? Was the instruction successful? Analyze samples of student work particularly that which is unsatisfactory, for the purpose of planning further instruction.)
REFINEMENT--Lesson Extension and Follow-up: (To be filled in as the lesson is modified during initial planning and/or during the teaching learning process.)