Battery Storage, Testing, Diagnosis, Charging Procedure and Parasitic Loads

I. BATTERY STORAGE

Today's vehicles have several electronic devices which result in very small but continuous current drains on their batteries, commonly referred to as "parasitic loads." Vehicles that are not used for an extended period of time may develop extremely discharged and/or permanently damaged batteries resulting from these parasitic loads. Discharged batteries can freeze at temperatures as high as 20 degrees Fahrenheit causing permanent damage.

TO ALLEVIATE THIS CONDITION, THE NEGATIVE BATTERY CABLE, SHOULD BE DISCONNECTED ON VEHICLES WHICH ARE NOT GOING TO BE IN SERVICE WITHIN A 30-DAY PERIOD. IF THIS IS NOT POSSIBLE, BATTERIES SHOULD BE RECHARGED PERIODICALLY, EVERY 30-60 DAYS, UNTIL THE GREEN DOT IS VISIBLE.
NOTICE: THE IGNITION SWITCH MUST BE OFF WHEN CONNECTING OR DISCONNECTING BATTERY CABLES OR CHARGERS. FAILURE TO DO SO MAY OVERSTRESS OR DAMAGE THE ECM OR OTHER ELECTRONIC COMPONENTS.

II. TESTING THE BATTERY

The cause of all no-start, slow cranking and/or frequently discharged battery conditions should be thoroughly diagnosed to avoid unnecessary replacement of Delco Freedom batteries. The battery should be charged and load tested in accordance with established service procedures as described in the Service Manual before considering battery replacement.

III. DIAGNOSIS AND CHARGING PROCEDURE

The following information will explain the characteristics of the Delco Freedom battery and the effects of parasitic loads (small constant drains on the battery due to standard and optional equipment). The effect of outside temperatures on battery power and proper battery charging and testing procedures are also discussed.

Read all this information; try recharging a deeply discharged battery, review training materials if necessary, and become convinced that Delco batteries are GOOD batteries. Most deeply discharged batteries CAN be recharged if proper procedures are followed.

Examples of conditions causing low charged or discharged batteries are:

- Extended storage of vehicles
- Batteries being less than adequately charged when received
- Extended cranking periods due to plug fouling
- Driver habits
- Incorrect interpretation of the charge indicator
- Inability to determine the correct ampere-hour charging rate for a discharged battery
- Burned out charge/gen light bulb causing "No Charge" condition
- Charging system problems
- Continuous current draw on the battery thru increased parasitic drain

PARASITIC LOADS

Pontiac vehicles may have several electrical devices which result in continuous current drains on their batteries. Batteries on vehicles not being used for an extended period may become discharged by these small current drains called parasitic loads.

Any battery discharged by parasitic loading and then allowed to stand in this condition for a period of time may not readily accept recharge. However, if properly recharged, batteries will return to a good usable condition.

Extremely discharged batteries can freeze at temperatures as high as +20 degrees Fahrenheit, and freezing can also cause permanent damage. Permanent damage to discharged batteries can also be accelerated by high temperatures.

FIGURE 1:

Figure 1 shows what happens to available battery power and the power required to start the engine at different outside temperatures.

FIGURE 2:

Figure 2 shows a typical amount of current used in getting a vehicle built and delivered to the dealer, how much is available for electrical devices, and how much is necessary to start the vehicle. The battery begins to be discharged at the time it is connected. Current is used during plant build, carrier handling, dealer storage, and new car preparation. During this entire period, the vehicle is never driven long enough nor at a high enough RPM to bring the battery back up to a full state of charge.
A vehicle sitting for 2 months at 32 degrees Fahrenheit most likely will not start due to parasitic load and self-discharge.

Examples of parasitic loads:

DEVICE MILLIAMP DRAW

Voltage Regulator 1 - 2
Digital Clock 3 - 4.5
Quartz Clock 7
ECM 6.5 - 8
ETR Radio and Clock 7
Load Leveling 4
Memory Seat 3
Twilight Sentinel 3

TYPICAL PARASITIC LOADS

LOAD (MILLIAMPS) AT
MODEL 12.6 BATTERY VOLTS

Fiero 11
Grand Am 10
Firebird 10
Sunbird (2000) 10
Bonneville 9
6000 8
STE 18
Safari Wagon 10

Chemical reactions take place in all batteries, even if they are not connected to a load. Therefore, a certain amount of self-discharge is always occurring. The higher the ambient temperature, the greater the amount of self-discharge. This explains why the number of discharged batteries increases in very hot weather. The Delco Freedom battery has a much lower rate of self-discharge than conventional batteries.

The chart below demonstrates how the increased temperature affects self-discharge.

RATE OF
TEMP. SELF-DISCHARGE (AMPS)

120 .0112
100 .0068
70 .0018
50 .0008

To prevent battery damage and difficulty in recharging, any vehicles that are not going to be in service within a 30-60 day period should have ground cable(s) disconnected to remove the constant drain on the batteries. If this is not possible, batteries should be recharged periodically every 30-60 days until the green dot is visible. The longer a vehicle sits on a dealer's lot with the battery cables connected, the higher the probability that it will have to be recharged due to the drain caused by parasiticloads and self-discharge.