Red Battery Light On Dashboard

What Car Battery Light Means

When vehicle is running trouble free usually the dashboard is clear of any warning lights. You will notice immediately if any of the warning lights come on. Rated by severity of the problem you could see amber/yellow or red lights show up while driving. Red battery light on usually means battery charging problem.

Car Battery Light On While Driving

Red battery light comes on when cars computer detects lower voltage in battery charging circuit. If you vehicle does not have battery charging gauge then it’s hard to tell how serious is a battery light warning. Here are common problems that trigger red battery light warning:

  • Blown alternator fuse
  • Loose wire connection
  • Alternator not charging
  • Bad Alternator
  • Bad Voltage Regulator
  • Bad Relay

Red battery light only means a drop of alternator output below 12 volts. To find out how serious the problem is you will need to test the battery and alternator.

What to do when battery light comes on

If your battery warning light comes on while driving it is best to keep driving and NOT try to shut off the engine and try to make it to the nearest auto repair shop or mechanic.
How long will an alternator last after the battery light comes on depends on the age of the battery state of charge. Battery light may stay on even if alternator is charging or vice versa – alternator not charging but no battery light.

Very often people confuse dashboard warning lights while vehicle engine is not running and key is just in ignition ON position. If your car is not starting and you see battery light airbag light, oil level lights are on that is normal and does not indicate a problem yet. You will have my battery light on but car starts fine and it goes off when engine starts.

If a battery light comes on then goes off when accelerating that could mean worn out belt or failing bearing. In this case alternator not charging battery at idle, but as you accelerate and engine RPMs increases the alternator pulley starts spinning and light turns off. Same problem may persist when battery light comes on after 5 min of driving.

How Long Can You Drive With Battery Light On?

The vehicle will continue driving normal as usual even after the battery light comes on.
It is safe to drive car with the battery light on for short distance. You can still drive 30 to 60 minutes after battery light on and car battery not charging while driving. Turn off all unnecessary accessories like radio, phone charger, air conditioning to conserve battery power.

In some cases you may see flicker battery light on and off while driving, this could be due to lose connection at alternator output connection or at battery terminal. And alternator stops charging randomly while driving.

How can you tell if its the battery or alternator?

When car is not starting after it was parked for some time it is usually because of bad battery and needs mobile car battery replacement. A red battery light warning on the dash while driving definitely indicated a problem with alternator and may start shutting down. Also if car doesn’t stay running after jump start it’s because alternator is not charging the battery.

How do I fix the battery light on my dashboard?

Many dashboard warning lights like TPMS, Check Engine or Air Bag can be reset and turned off with OBD tools. Looking how to reset the car battery light? Battery light resets automatically if alternator charging voltage is around 14.8 volts. So you may have a question
“how can I make my alternator work again?” Although alternators can be repaired it is faster and cheaper to replace the whole part with new one.

Why would alternator stop working?

Vehicle alternator is driven by serpentine belt and is directly to connected to harmonic balancer pulley, that is attached to the crankshaft. Anytime engine is running the alternator is spinning. Alternators have many moving parts and over time working in hot engine they wear out and alternator stops working. Most common breakdowns are:

  • Bearing failure
  • Worn out brushes
  • Stator windings
  • Internal heat damage

How much does it cost to fix an alternator?

An average price of new or remanufactured alternator is around $300. The installation and labor cost will vary depending on the vehicle and how difficult it is to install it.

How long cars alternator lasts?

Automotive alternators have an average lifespan of 70,000 to 150,000 miles. The most important factor in how long alternator lasts is the quality of the parts.