GM “Battery Saver Active” (Meaning + Diagnosis)

Many modern GM made vehicles have a battery saver feature.  If you are getting a “battery saver active” message, it means that your car or truck has detected that the voltage in the electrical system is less than 11.7 volts.  This is over a volt off of the normal system voltage of around 13- 14 volts.

When the battery saver is active, it causes many of the vehicles non essential functions to stop (including the air conditioner), in order to increase battery life.  If electrical voltage gets much lower than the 11.7 that it’s at when the battery saver is active, the engine will no longer be able to run properly. 

Battery saver increases the driving range of the vehicle when the system is not properly charging.  If this feature is on, assume that your vehicle will stop running and get it fixed immediately.

Battery Saver Active Diagnosis

Battery Saver Active: Causes

The battery saver is usually activated when an alternator goes bad, but there can be other causes as well.

 

Battery Cable

Before jumping straight to the alternator or battery, it’s a good idea to take a look at the battery posts.  If they look corroded, clean them off with a wire brush.  There are also specialized battery cleaning tools that you can pick up at Autozone or Wal-Mart for around $5.

 

Bad Alternator

If the battery saver light came on when you were already driving, that is a strong indicator that the alternator is bad.  With the engine running, the alternator should be putting out at least 13 volts with everything on.  

It’s very easy to see if the alternator is bad.  You need a voltage meter, that’s about it.  The alternator could be all the way bad (not charging the battery at all).  Or it can be going bad, which means that it is charging some, but not enough to meet the needs of the vehicle.  Here’s a great video from ChrisFix on how to test the alternator yourself.

 

Bad Battery

If the alternator appears to be fine from your testing (and the battery cables are clean) that leaves the battery and battery current sensor.  It would still be wise to have the battery tested before it is replaced.  It could still be the battery current sensor that is at fault.

 

Battery Current Sensor

This sensor determines whether or not current is flowing in or out of the battery.  It is connected to the negative battery terminal.  Here’s a great video on how to diagnose a bad battery sensor.

 

Conclusion

The “battery saver active” notification means that there is some issue with the charging system.  Either it’s not storing enough voltage (battery), not creating enough voltage (alternator), or the voltage is getting lost from the alternator to the battery (bad cables/corroded terminals).

Good luck fixing your vehicle!

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