2009, 87K miles, V6.

Car started sounding like normal cranking. Battery light stayed on for drive home (10 mins). Checked voltage across battery when running and it was 14.3 volts. Shut off, battery at 12.9 volts.

I have a charger on it now but I don't think it's going to charge much from there.

What do I check next? Are there common failures that might cause the check system itself to be in error? Ideas?

EDIT: Battery is from 02/2019, so I am assuming it's good (I know that's not always true :-)

Thanks,

 

If your battery light is on its for the alternator. Have it tested to make sure it's good. You may just have a cable issue

 

Sean: Thanks...
Updated info... after charging last night, the battery light is off. But, again, the battery was strong when tested before that at 12.9 volts, car off. Showing 13.4 after charging

Question 1: If the battery was drained (low draw), would the battery light be on simply because it was charging at a slightly higher rate? We know the alternator is charging after every start, but would a higher charge rate light the dash indicator?

Question 2: If the indicator came on from a dip in voltage when starting, would it stay on until the car was shut off/restarted? OR would it shut off as soon as normal charge levels were reached?

Question 3: Is there anything that can even be left powered up in these cars short of the headlights being left on? It appears to me that the USB ports all shut down when you shut the car off. There were devices plugged in to the front port (near shifter) while parked for 12 hours.

 

The battery light turning on doesn't necessarily mean the battery is discharged, it means the car detected a charging issue with the vehicle. You have to test the battery and alternator systems to determine the root issue.

 

In fact, I've left lights or things turned on (in a number of different cars) and the warning light never came on from the battery having low-voltage.

Its misleading that the warning light is the shape of a battery, because it really means the charging system has a problem.

 

+1 have the alternator tested. It may be going bad or a cable issue. I've never seen the battery light be for anything else

 

If you're getting voltage over 12,3 volts your altenators good. The light comes on when there is a drop in voltage normally. It doesn't necessarily have to be the battery that's losing voltage like if you have a bad connection. There are other instances where it would stay on but that's normally with other types of cars and has to do with the voltage regulators. I'd swear this reminds me of that. Or a failing diode in the alternator.

 

Does disconnecting the battery have any other implications like "radio code needed", etc?

This car is showroom clean because it's in the Southwest. You could eat off this engine and not worry. I'd be shocked if it had a corroded connection. But I'll try to poke around there and see if anything is looking odd.

I am correct that the light would go off if the problem corrected itself while driving, right? It won't stay on until the next start cycle, will it?

 

You will need the radio and navigation code if equipped.

The battery light should go off if the system does not see the problem. I would suggest having the alternator tested because I'm sure there is no wire issue unless the engine gets cleaned with a hose. You would have to test voltage if it's not the alternator going bad.

 

Well, since the original poster is talking about a 2009 Accord, here 2 things...

Disconnecting the battery will not reset the PCM. Starting in 2003 the Accord used non-volatile memory.

The car IS OBD-2 so yes his 2009 car does normal OBDs.