1 Change a car dead battery

This solution was generated from a YouTube video.

Source: “How to Change a Car Battery | DIY Car Repairs | The Home Depot” (https://www.youtube.com/watch?v=0JE-VbmzQzo)

1.1 Preparation

General Human Requirements:

  • Enough strength to carry a battery
  • Ability to bend the back
  • knowledge of using various tools (see invdidual tasks)
  • Knowledge of the safety precautions to change a battery
  • Ability to move the body

Context/Environment:

  • Car’s lights are weak and dim
  • The engine is off
  • The car has an autmatic trasmission in park
  • Corroded battery terminals
  • Parking brake applied
  • Sufficient light (natural or artificial)
  • Good weather conditions(no rain or snow)
  • A new car battery in the trunk
  • Various tools in the trunk (see individual tasks)
  • The key is removed from the Vehicle
  • The engine is fully cool

1.2 Open the Vehicle’s hood

Task:

  1. Look for a release latch inside the cabin of the car and release it to start opening the hood
  2. Position yourself by the front of the hood to release it
  3. open the hood by releasing the clamp under it
  4. Prop the hood open to hold it in place using the prop rod

Open the Vehicle’s hood

Design Variables:

  • Place of the hood latch
  • The weight of the hood
  • hand clearance under the hood around the clamp
  • Place of the prop rod
  • size of the hood

Human Characteristics:

  • Strength of the arms
  • size of the hands
  • flexibility of the body
  • The ability to stand

1.3 Detach cables by loosen the nuts

Task:

  1. locate the battery under the hood and identify the negative and positive terminals
  2. remove the cover if necessary
  3. wear work gloves
  4. lift the wrench and attach it to nuts
  5. use the wrench to apply torque to loosen the nuts from terminals
  6. detach the negative cable first then the positive cable

loosen the attached nuts

Design Variables:

  • weight and size of wrench
  • length of the wrench
  • grip design of the wrench
  • the place of the battery
  • number of nuts
  • visibility of the negative and positive cables
  • the space around the battery
  • the size of the nuts that hold the cables
  • hand clearance around the battery
  • the position of the battery
  • the length of the cables attached to the battery

Human Characteristics:

  • hand size
  • the flexibility of the back
  • the wrist strength and movement
  • hand grip strength
  • fingers dimensions

1.4 remove clamps or brackets securing the battery

Task:

  1. Lift extender and attach it to the socket wrench and apply it to brackets nuts
  2. Apply torque to the end of the socket extender to loosen the nuts
  3. Lift the clamps and brackets
  4. set them aside from the battery

Detach the cables from the battery

Design Variables:

  • Number of nuts
  • Wrench extender length
  • Grip design on extender wrench
  • size of the clamps
  • nuts diameter
  • position of the supporting brackets

Human Characteristics:

  • ability to bend the back
  • ability to move hands
  • size of the hand
  • hand clearance

1.5 lift the battery from its position

Task:

  1. hold the battery by its connected handle using both hands to easily carrying it
  2. lift the battery from its current position
  3. place the battery aside from the car
  4. use a wire brush and battery cleaning solution to wipe the tray and the connectors
  5. use a towel to dry them

Clean the connectors

dry the connectors

Design Variables:

  • The length of the battery handle
  • the size of the battery
  • the weight of the battery
  • the size of the battery tray
  • battery position under the hood

Human Characteristics:

  • ability to lift the battery
  • The arms strength to carry the battery
  • the size of the hand
  • the ability to move while carrying an object

1.6 Install the new battery

Task:

  1. using both hands to carry the new battery from its current position to install it under the hood
  2. Place the new battery in its tray
  3. place the positive terminals by the red cable
  4. place the negative terminals by the black cable
  5. remove the covers from the new battery terminals
  6. spray the battery post with an anti corrosive solution

Insert the new battery in its tray

Spray the post with anti corrosive solution

Design Variables:

  • Size of tray
  • weight and size of the new battery
  • battery position
  • location of the terminals
  • location and length of the cables

Human Characteristics:

  • ability to lift the battery
  • The arms and hands strength to carry the battery
  • the size of the hand
  • the ability to move while carrying an object

1.7 Connect the cables and tighten the nuts

Task:

  1. attach the red cable to the positive terminal
  2. lift the nut and attach it to secure the red cable with the positive terminal
  3. lift and use the wrench to tighten the nut to the positive terminal
  4. put away the wrench
  5. attach the black cable to the negative terminal
  6. lift the nut and attach it to secure the black cable with the negative terminal
  7. lift and use the wrench to tighten the nut to the positive terminal
  8. lift the supporting brackets and place them in their positions
  9. lift the wrench extender and tighten the nuts attached to the brackets
  10. put all the tools back to the trunk

tighten the nuts

Design Variables:

  • weight and size of wrench and the wrench extender
  • length of the wrench
  • grip design of the wrench
  • the place of the battery
  • number of nuts
  • visibility of the negative and positive cables
  • the space around the battery
  • the size of the nuts that hold the cables
  • hand clearance around the battery
  • the position of the battery
  • the length of the cables attached to the battery

Human Characteristics:

  • hand size
  • Finger dexterity for handling nuts
  • the flexibility of the back
  • the wrist strength and movement
  • hand grip strength
  • fingers dimensions
  • the hand strength

1.8 closed the car hood

Task:

  1. hold the hood with one hand
  2. use the other hand to lower the prop rod
  3. use both hands after lowering the prop to close the hood
  4. start the engine to test the battery

start the engine

Design Variables:

  • the length of the prop rod
  • the weight of the hood
  • the prop rod diameter

Human Characteristics:

  • strength of hands
  • the arms length or outreach
  • the back strength
  • the hands grip