GM Metro/Sprint 1985-1993 Repair Guide

Battery

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All Sprint/Metro models have a Maintenance Free battery as standard equipment, eliminating the need for fluid level checks and the possibility of specific gravity tests. Never-the-less, the battery does require some attention.


CAUTION
Keep flames or sparks away from the battery. It gives off explosive hydrogen gas. The battery electrolyte contains sulfuric acid. If you should get any on your skin or in your eyes, flush the affected areas with plenty of clear water. If it lands in your eyes, seek medical help immediately.

GENERAL MAINTENANCE



See Figure 1



Click image to see an enlarged view

Fig. Fig. 1: Special tools are available for cleaning the posts and clamps on side terminal batteries.

At least once a year, the battery terminals and the cable clamps should be cleaned. Remove the side terminal bolts and the cables, negative cable first. Clean the cable clamps and the battery terminals with a wire brush until all corrosion, grease, etc. is removed and the metal is shiny. It is especially important to clean the inside of the clamp thoroughly. A small deposit of foreign material or oxidation will prevent a sound electrical connection and inhibit either starting or charging. Special tools are available for cleaning side terminal clamps and terminals.

Before installing the cables, loosen the battery hold-down clamp, remove the battery and check the battery tray. Clear it of any debris and check it for soundness. Rust should be wire brushed away and the metal given a coat of anti-rust paint. Replace the battery and tighten the hold-down clamp securely but be careful not to overtighten, which will crack the battery case.

Surface coatings on battery cases can actually conduct electricity which will cause a slight voltage drain, so make sure the battery case is clean. Batteries can be cleaned using a paste made from mixture of baking soda and water. Spread the paste on any corrosion, wait a few minutes, and rinse with water. Finish the job by cleaning metal parts with a wire brush.

After the clamps and terminals are clean, reinstall the cables, negative cable last. Give the clamps and terminals a thin external coat of nonmetallic grease after installation, to retard corrosion.

Cables

Check the cables at the same time that the terminals are cleaned. If the cable insulation is cracked, broken or the ends are frayed, the cable should be replaced with a new one of the same length and gauge. Cables can be checked for continuity with an ohmmeter.

TESTING



See Figures 2 and 3

Maintenance free batteries, do not require normal attention as far as fluid level checks are concerned. The sealed top battery cannot be checked for charge using a hydrometer, since there is no provision for access to the electrolyte. Check the condition of the battery as follows:

  1. If the indicator eye on top of the battery is dark, the battery has enough fluid. If the eye is lit (light yellow or bright), the electrolyte fluid is too low and the battery must be replaced.
  2.  
  3. If a green dot appears in the middle of the eye, the battery is sufficiently charged. If no green dot is visible, charge the battery.
  4.  
  5. It may be necessary to tip the battery from side-to-side to get the green dot to appear after charging.
  6.  



Click image to see an enlarged view

Fig. Fig. 2: Maintenance free batteries contain their own built in hydrometer.

  1. After charging the battery, connect a battery load tester and a voltmeter across the battery terminals (the battery cables should be disconnected from the battery). Apply a load to the battery for 15 seconds to remove the surface charge. Remove the load.
  2.  
  3. Wait 15 seconds to allow the battery to recover. Apply the load again for 15 seconds while reading the voltage. Remove the load.
  4.  



Click image to see an enlarged view

Fig. Fig. 3: Battery minimum voltage specifications

  1. Check the results against the chart. If the battery voltage is at or above the specified voltage for the temperature listed, the battery is good. It the voltage falls below what's listed, the battery should be replaced.
  2.  

CHARGING OF BATTERY



When it is necessary to charge a battery several cautions should be observed.



Do not charge an extremely cold battery. The battery may not accept current for several hours after charging has begun.
 
The charging area should be well ventilated.
 
If the battery feels hotter than 125°F during charging, or if violent gassing or spewing of electrolyte through the vent holes occurs, discontinue charging or reduce the charging rate.
 

  1. Batteries with a built-in hydrometer showing a green dot do not require charging unless they have just been discharged by cranking the engine or leaving the lights on.
  2.  
  3. Connect the battery charger cables to the positive and negative battery terminals. Make sure all charger connections are clean and tight.
  4.  
  5. Charge the battery using the charge setting for 12V DC batteries that gives the highest charge rate to the battery.
  6.  
  7. Charge the battery until the green dot appears in the hydrometer. Check the battery every half-hour. The battery may need to be tipped or gently shaken for the green dot to appear.
  8.  
  9. Test the battery after charging and replace as necessary.
  10.  

BATTERY REPLACEMENT



See Figure 4

  1. Disconnect the negative battery cable from the negative battery terminal.
  2.  
  3. Disconnect the positive battery cable from the positive battery terminal.
  4.  



Click image to see an enlarged view

Fig. Fig. 4: Battery, cables, carrier and hold down brackets

  1. Remove the hold down nuts and battery retainer from the brackets.
  2.  
  3. Carefully lift the battery from the engine compartment.
  4.  

To install:
  1. Clean the battery tray and terminal ends of all corrosion.
  2.  
  3. Install the battery in the engine compartment and position in the tray.
  4.  
  5. Install the battery retainer and tighten nuts to 71 inch lbs. (8 Nm).
  6.  
  7. Install the positive battery cable on the positive battery terminal and tighten the nut to 11 ft. lbs. (15 Nm).
  8.  
  9. Install the negative battery cable on the negative battery terminal and tighten the nut to 11 ft. lbs. (15 Nm).
  10.  

 
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