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Battery light on for first 5 miles but voltage at 14.2V

I have a 2007 Saturn Vue V6 2wh drive approximately 195,000 miles, just replaced the battery in the fall. The Car starts just fine… but after 2-3 minutes the Battery light goes on and stays on for 5-10 minutes – then goes off. I have one of the ODM plug ins that transfers info to my cell and the Voltage in the system is starts at 14.3V and stays approximately 14.2 +/- 0.1V while driving.

Its been happening for a couple of weeks since I left something plugged into the 12 outlet overnight. I have tried to charge the battery (without disconnecting the lead) a couple of times since. But this has not corrected the issue.

Any suggestions on how I can correct this?

Could be the new battery is not taking and holding a charge. That can happen. Or something is drawing down power overnight and the high charge rate results.

What’s its voltage in the AM before you start the engine? I would measure the state of charge in each cell in the AM (if the caps can be removed) or have it tested by one of those newer electronic testing devices.

That is likely the charging voltage. The alternator is trying its darndest to charge the battery or else the voltage regulator in the alternator is fried. Take the voltage reading off the battery itself at rest to see if it is still at 14. May need to have the alternator checked.

If the alternator is really outputting 14.2 V at highway speeds , unlikely any problem w/the alternator itself. Could be a problematic voltage regulator though, which would required the alternator be replaced as the VR is porbably part of the alternator. But the more likely culprit, something wrong with the electronics that turns on that dash warning light. i.e. it is being turned on when there’s actually no problem. ecm problem or loose wire connection or faulty dash warning panel.

I have a 2007 Saturn Vue V6 2wh drive approximately 195,000 miles, just replaced the battery in the fall. The Car starts just fine… but after 2-3 minutes the Battery light goes on and stays on for 5-10 minutes – then goes off. I have one of the ODM plug ins that transfers info to my cell and the Voltage in the system is starts at 14.3V and stays approximately 14.2 +/- 0.1V while driving.
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Hello!

It seems that your voltage regulator is faulty.
I would meassure the actual voltages on the battery posts, just to be on the safe side.
Use mulitmeter tool, swithced to Voltage.
You should get ~12V when engine off, and ~14V with engine running.

Harvey

To update: Initially thanks to everyone for their suggestions to date:. FYI I have had several replies and one from a mechanic friend who said disconnect the battery for 30 minutes or so to see if it resets the computer. I did that this morning… I also attempted Mr. Spector’s instructions" using a digital VOM member the Battery Voltage was 12.58 V without the car running (and before I started it for the day in a 25F garage). After wIth the car running the battery voltage was at 14.57V. The ODM reader still said 14.2V… and the light still came back on for a few minutes after I started the vehicle. I guess I am going to have to have the Alternator and VR checked professionally…

Yeah like we said. Most alternators now have the voltage regulator inside the alternator so usually it is replacing the whole alternator. In the old days, regulators were sometimes mounted outside of the alternator/generator. Like said though, when you start the car, the voltage readings you are seeing are from the alternator.

The warning light can illuminate when there is a failing diode in the alternator, it may still put out the requested voltage but not the rated current capacity. Have the alternator tested (in the vehicle, do not remove for testing).

Unlikely to apply to a 2007 Saturn, but my 27 year old Corolla is designed so that both the alternator warning light and the brake warning light turn on when the alternator fails. I presume this is sort of a backup system, so if he alternator fails and its dash warning light fails too, the brake warning light still alerts the driver that a visit to the shop is an immediate necessity. OP should double check the owner’s manual to verify the alternator warning light isn’t shared as a back-up warning light for another system.

The voltage regulation diodes often cost nearly as much or more than the alternator. I have had a couple of these modules fail as well and looked at replacing just the module. The lifetime warranty new alternator was basically the same price as only the module so I didn’t bother.

It seems like everything is going this way from computers to kitchen appliances. I recently had to change out an entire crockpot because the replacement crock cost more than the entire unit. The same happened with a food processor when the cheap hard plastic decided to crack one day. The container alone cost more than a new unit.

At least there was a core charge with my old alternators so I am sure they will be rebuilt and live on as remanufactured models.

I don’t remember the exact cost anymore but when I used to just overhaul my alternators, I think I got everything for around $25-30. Front bearing, diodes, voltage regulator, brushes, and sometimes the rear bearing. I think the diodes were about $5 at NAPA.