E.Load Testing

Load testing requires use of battery side terminal adapter the same as with charging to ensure good connections. (See Section II, Step C, Page 3.)

1. The following specifications are recommendations for test equipment to accurately load test any battery:

^ Variable Load Resistor - 0-500 ampere minimum (required to apply load test as shown on label of battery).

^ Ammeter - 0-500 ampere minimum capability, +/- 2% full scale accuracy. Scale should permit accurate readings to 10 ampere increments.

^ Voltmeter - 0-16 volts minimum capability, +/- 1% full scale accuracy. Scale should permit accurate readings to .1 of one volt increments. Separate digital meters can be used because of of their accuracy.

^ Anti-static meter faces.

^ Zero adjustment provisions.
^ Meter reading accurate in either vertical or horizontal position of tester.

^ Voltmeter sense point should be within .05 volt maximum of battery terminal voltage at full load.

^ Timer - 15 second interval +/- 1 second. This is optional since watches with second readability are common.


2. Connect a voltmeter and a battery load tester across battery terminals.


3. Apply 300 ampere load for 15 seconds to remove surface charge from batteries that have been on charge during the past 24 hours. This includes batteries charged by the vehicle's charging system. Since a battery loses its surface charge within 24 hours, the 300 ampere load should not be applied to batteries that have not been charged within that time period. Remove load.


4. Wait 15 seconds to let battery recover and apply test load as specified in Figure #4 below, or Chevrolet Shop Manual. Starting with 1980 models, the load test amps and cold cranking amps appear on the battery label. It is very important, when performing a battery load test, that the load and time duration be accurately controlled, and all lights and accessories must be off. Read voltage after 15 seconds with test load applied, then remove load.


5. Temperature of the battery will change the minimum voltage to pass the load test. To properly determine minimum voltage, estimate temperature battery has been exposed to for the last several hours, i.e., room temperature or outside ambient, to within 10~F. If voltage is equal to or above minimum voltage listed in Figure 5, below, battery is good and should be returned to service. If voltage is less than minimum requirement, replace battery.