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Battery inspection

Tips on inspection

  • Battery electrolyte level
    See the "Battery electrolyte inspections" section
  • Terminal looseness inspection
    Use gloves to avoid electric shock and manually check for loose connections. If it is loose, tighten with a wrench or other tool.
  • Keep it clean and dry
    When wiping down the battery, use a damp cloth or an antistatic cloth to avoid sparks caused by static electricity.
  • Inspection notes
    • Never bring a flame or lighted cigarette near a battery.
    • Be very careful not to create sparks by short-circuiting the battery with metal tools such as wrenches.
    • Charge in a well ventilated area, when charging a battery with jumper cables or a charger.
    • Do not disassemble or modify batteries.


Check battery electrolyte level regularly

Using a battery with insufficient battery electrolyte may cause an explosion.

  1. Insufficient battery electrolyte
    Continuing to use a battery whose battery electrolyte is below the prescribed level will expose the metal parts of the battery, contributing to their degradation.
  2. Accelerated degradation
    As degradation progresses, the degraded parts may give off sparks.
  3. The internal gas may ignite.
    There have been cases in which a spark has ignited the hydrogen gas collecting inside the battery (this gas can also occur when charging a battery or when self-discharging), resulting in an explosion.
  4. As the battery electrolyte decreases, the volume of hydrogen gas inside the battery increases, which can cause a large explosion.
  5. Be careful of fire.
    1. Sparks may also be caused by a loose connection at a terminal or by short-circuiting the positive terminal and the negative terminal or the positive terminal and the car body with a metal tool.
    2. The gas may also be ignited by a lit cigarette.

Explosions and their causes: automobiles and construction and farm equipment that use old lead batteries

Explosion incidents in fiscal 2008

Causes of explosions in fiscal 2008

  • Incidents involving buses, trucks, and taxis have been increasing at over 20 per year since 2001, with an all-time high of 33 in 2008 (an incident rate of 56%).
  • The number of incidents involving construction and farm equipment has also been on the rise since fiscal 2001, and in fiscal 2008 the incident rate was 32%.
  • In most instances, the causes were attributable to lack of maintenance or improper installation when replacing the battery.

Causes of explosions in fiscal 2008 59 incidents by type
Low battery electrolyte: 34 (58%)
Dirty battery: 5 (8%)
Loose terminals: 1 (2%)
External short-circuit: 4 (7%)
Other: 15 (25%)

Battery electrolyte level inspection manual

1. Why does the battery electrode decrease?

This phenomenon occurs primarily during recharging (while the vehicle is running). The battery electrolyte decreases when excess energy is applied to the battery over the storage capacity (over charging), and the water in the battery electrolyte decomposes into oxygen and hydrogen gases. The battery electrolyte also decreases through natural evaporation. Thus, when the temperature around the battery is high, or when the battery is used frequently (deep charge and discharge applications, such as day and night lighting, refrigeration units, power gates) or when the battery is near the end of its life, the battery electrolyte decreases a lot in a short period of time. The battery electrolyte decreases when it is being used, thus daily inspections of the battery electrolyte level are necessary.

Advice
If the battery is used when the battery electrolyte is at the LOWER LEVEL mark, the degradation of internal metal parts and the reduction of battery electrolyte are accelerated, and the possibility of an explosion increases, so it is advisable to replace the battery.


2. How to perform a battery electrolyte level inspection

1. When a battery electrolyte level indicator is located on the side of the battery

Advice
When there is a battery electrolyte level indicator, use it to verify the level.

Clean the battery electrolyte level indicator with a cloth moistened with water, and check that the battery electrolyte level is between the UPPER LEVEL and LOWER LEVEL lines. If a dry cloth is used to clean the indicator, static electricity may ignite a fire and cause an explosion.

When the battery electrolyte level is lower than half way between the UPPER LEVEL and LOWER LEVEL lines, immediately add purified water (battery electrolyte replenish solution, or similar solution available commercially) until the battery electrolyte level is at the UPPER LEVEL mark. After adding battery electrolyte, be sure to tighten the vent plugs.

Remove the plugs from the top of the battery and look into the battery to verify the battery electrolyte level. If the battery electrolyte level is lower than the sleeve, be sure to add purified water (battery electrolyte replenish solution, or similar solution available commercially) until the battery electrolyte reaches the bottom of the sleeve.

If too much purified water is added and the battery electrolyte level goes beyond the UPPER LEVEL mark or the bottom of the sleeve, use a dropper to remove water until the level drops to the UPPER LEVEL mark or bottom of the sleeve. After removing battery electrolyte, neutralize the acid with baking soda (bicarbonate of soda) and then flush thoroughly with water. Otherwise consult the battery manufacturer. If the battery is used while the electrolyte is at the LOWER LEVEL mark, the internal parts will degrade quickly, and even if the electrolyte levels are brought up to normal, they will decrease immediately, so please check frequently and add fluid when necessary.