Red Battery Warning Light After Trickle Charging

[sethsquire]

I have a third car for a few months so the Blackwing is mostly chilling in the garage, and I purchased a Noco trickle charger to make sure the battery doesn't go dead. I placed it on the terminals under the hood, it blinked red for while indicating that it was charging before eventually going green, and has stayed like that for the last couple of weeks.

I felt like taking a drive today and pulled off the charger and fired up the car. Immediately the red battery warning light illuminated on the dash. I drove a short distance, turned the car off and turned it on again and the battery light disappeared. It did not reappear and the car seemed to be functioning within normal parameters.

Has anyone else experienced this?

 

[jbawden]

My 5 has been on a Noco maintainer using under hood terminals for 2.5 years with occasional weekend use and never have seen a battery light.

 

[1Evil55]

My 5 has been on a Noco maintainer using under hood terminals for 2.5 years with occasional weekend use and never have seen a battery light.

+1
Usually always keep the trickle on mine when not using. Same battery since Dec. '21.

 

[Ty88]

I have a third car for a few months so the Blackwing is mostly chilling in the garage, and I purchased a Noco trickle charger to make sure the battery doesn't go dead. I placed it on the terminals under the hood, it blinked red for while indicating that it was charging before eventually going green, and has stayed like that for the last couple of weeks.

I felt like taking a drive today and pulled off the charger and fired up the car. Immediately the red battery warning light illuminated on the dash. I drove a short distance, turned the car off and turned it on again and the battery light disappeared. It did not reappear and the car seemed to be functioning within normal parameters.

Has anyone else experienced this?

Sounds like your charger may not be charging or maintaining and the battery got low enough to trip the light then got charged back up again when you drove the car. I would test the charger or replace it.

 

[+ManifoldPSI]

Sounds like your charger may not be charging or maintaining and the battery got low enough to trip the light then got charged back up again when you drove the car. I would test the charger or replace it.

If he only drove a short while, and after a cold start too, the duration of the drive may not have been enough to put much of any charge in the battery.

That being said, I would agree with testing the charger and keeping an eye on the charge level.

I set up a trickle charger on my '25 5VBW about 5 weeks ago and have not noticed any issues either. It does seem most active of all the car/trickle charger setups I have had in totality. Complex car draws a lot of battery power sitting idle, locked or not, it seems. My 12 valve is the polar opposite- can sit for a month with a single battery (probably not all that much bigger than the Caddy's in terms of CCA/reserve either) and starts right up. Starter sounds like it is cranking with full juice to boot.

 

[sethsquire]

Sounds like your charger may not be charging or maintaining and the battery got low enough to trip the light then got charged back up again when you drove the car. I would test the charger or replace it.

It's possible, but the light on the charger went red to indicate charging and then green to indicate/charged maintaining, so it at least thought it had charged the battery. Typically when I see the red battery icon I think alternator issue.

Anyway, going to fire it up and go on a long drive tomorrow so I'll see if it reappears.

 

[hawk02]

You might want to have your dealer test your battery. I just had the one in my ’23 BW replaced because of a bad cell. Mine was showing less than 8 volts after sitting for 12 days — the car was deader than a doorknob. I couldn’t even unlock the doors with the key fob. My little 1.2-amp trickle charger threw an error light when I tried to charge it, so I ended up buying a NOCO 10-amp charger. That finally got enough charge into it to start the car and get it to the dealer. Just a heads-up: the current Cadillac battery test procedure takes about two hours.

 

[sethsquire]

You might want to have your dealer test your battery. I just had the one in my ’23 BW replaced because of a bad cell. Mine was showing less than 8 volts after sitting for 12 days — the car was deader than a doorknob. I couldn’t even unlock the doors with the key fob. My little 1.2-amp trickle charger threw an error light when I tried to charge it, so I ended up buying a NOCO 10-amp charger. That finally got enough charge into it to start the car and get it to the dealer. Just a heads-up: the current Cadillac battery test procedure takes about two hours.

Thanks, I think I might do that. It happened again today, though under different circumstances. I disconnected the trickle charger, got in the car, drove 50 miles without incident. When I fired up the car to drive the 50 miles back, the red battery light appeared again. At this point I realized the car had a voltmeter, pulled it up and it was reading around 13 volts. Turned the car off and on again and once again the battery light disappeared, and held a steady 12.5 volts during my whole drive, which should be normal. Very confusing...

I'm thinking I should indeed have it checked while the car is still under warranty.

 

[hawk02]

I configured the voltmeter to permanently display on the DIC right after my battery was replaced. If the car has been sitting for a few days, the voltmeter reads around 11.9 volts at startup. Once I start driving, it quickly rises to about 14 volts or a little higher.

I also bought a Foxwell battery analyzer from Amazon. With the original battery, my NOCO 10-amp charger would indicate that the battery was fully charged, but the Foxwell analyzer would report that it needed to be recharged. That discrepancy is what prompted me to take the car to the dealer and have the battery tested.

 

[sethsquire]

I configured the voltmeter to permanently display on the DIC right after my battery was replaced. If the car has been sitting for a few days, the voltmeter reads around 11.9 volts at startup. Once I start driving, it quickly rises to about 14 volts or a little higher.

I also bought a Foxwell battery analyzer from Amazon. With the original battery, my NOCO 10-amp charger would indicate that the battery was fully charged, but the Foxwell analyzer would report that it needed to be recharged. That discrepancy is what prompted me to take the car to the dealer and have the battery tested.

Interesting. I just fired up the car in the garage to see if the battery light would appear. I did not put in back on the trickle charger after returning from my trip yesterday. It fired up just fine, no battery light. Started at about 12.5 volts and gradually made its way up to around 13.8/13.9 and stayed around there.

Like I mentioned before, the NOCO charger would indicate charging and then go green to indicate charged. However, my NOCO is a little 1 amp charger. Do you think it's possible it's just not sufficient to keep the battery charged? My understanding is that as long as it can charge the battery the ultimate ampage doesn't really matter, I'm just not well-versed enough on batteries to understand what the issue might be.

 

[hawk02]

Interesting. I just fired up the car in the garage to see if the battery light would appear. I did not put in back on the trickle charger after returning from my trip yesterday. It fired up just fine, no battery light. Started at about 12.5 volts and gradually made its way up to around 13.8/13.9 and stayed around there.

Like I mentioned before, the NOCO charger would indicate charging and then go green to indicate charged. However, my NOCO is a little 1 amp charger. Do you think it's possible it's just not sufficient to keep the battery charged? My understanding is that as long as it can charge the battery the ultimate ampage doesn't really matter, I'm just not well-versed enough on batteries to understand what the issue might be.

For comparison, my 1.25-amp Battery Tender brand threw a red error light when I hooked it up to the original battery in my BW, even though it worked fine on my wife’s Blazer. I even tried the “official” Cadillac battery conditioner. It ran for three full days straight and never got the battery fully charged—and got so hot you could barely touch it. That’s when I grabbed the NOCO 10-amp, and that one finally brought the battery back enough to get the car started. If it were me, I would take the car to the dealer and have the battery tested ASAP.