Curious thing i noticed with my 2006 dts LIII. Took a 3 hour trip out and back last Saturday and noticed that while driving the battery voltage was between 12.8-12.9; it is 14.4-14.6 when the car is just started. On Monday, i drove the car on four ten miles trips, same route back and forth. first two trips, the voltage stayed between 14.4-14.6. the second two trips later in the day, the voltage started at 14.4-14.6, but quickly dropped to 12.8-12.9. Tuesday and Wednesday, voltage stayed at 14.4-14.6 when driving.

Is this sporadic drop in battery voltage normal?

Also, the battery is very weak when starting the car, dont know if this is related to the voltage fluctuation.

Ideas? Thanks, Scott

If the battery is weak when you start it...I would take it in and have it checked.
The battery is covered under the 4 year/50,000 mile warranty.

As for the voltage...mine is usually at 14 something when I first start it, but drops back to the mid 13's pretty quick...than after driving for a while...it stays in the high 12's.

Texas Jim

ok, thanks. i bought a new battery and will put it in; car has 43,000 miles and battery is probably original. sounds like the voltage drop is normal

These amp gauges are about as accurate as the old analogue fuel gauges.

My amp gauge was showing 14.7 regularly.

Dealer tells me that I need to worry if my alt charges at the rate of anything above 14.4.

I take vehicle in--under warranty; new (not rebuilt) alt also routinely charges at 14.6 or so. That was a couple of years ago. Car, alt, and batt are much stronger than me.

ok, thanks. i bought a new battery and will put it in; car has 43,000 miles and battery is probably original. sounds like the voltage drop is normal


If the battery is weak..it is covered under warranty for 4 years or 50,000 miles.
Looks like you are still under warranty...save your money and let the dealer replace it.

Texas Jim

Obviously some people don't know the difference between current and voltage. The use of "amp gauges" went out with generators. The reading provided by the DIC is the system voltage.

Obviously some people don't know the difference between current and voltage. The use of "amp gauges" went out with generators. The reading provided by the DIC is the system voltage.

Yes, mother!! LOL

BTW, why did my 64 Lincoln have 'amp' printed on the gauge? Ford started using alternators in 62, methinks. At any rate, my Lincoln had an alternator.

What is the difference between current and voltage? I suspect others want to know.

i know that i dont know the difference, the electrical part of vehicles has always left me behind. i gather a generator produces amperage and an alternator produces voltage? where does current come in? i am stupid about this. but I am fairly good with replacing carbs and exhaust systems.

[QUOTE=RSD;1956844]i know that i dont know the difference, the electrical part of vehicles has always left me behind. i gather a generator produces amperage and an alternator produces voltage? where does current come in? i am stupid about this.

Should we agree with your last statement or not???? lol

Current is the flow of electrons produced by voltage. Amperes (A) are the units of measure of current flow. Volts (V) are the units of measure of voltage. In old generator systems brushes on a commutator produced direct current and voltage when the engine was running fast enough to run the car and charge the battery. Typically when engine RPM went down, as at idle, the generator would not produce enough output to run the car and charge the battery. In this case, the battery took over and provided the necessary current until engine RPM again went up and the generator could supply the car's needs and charge the battery. The so called "amp gauges" were placed in the supply path for the car's system, but not in the supply path for the starter motor. These meters were centered at zero and showed the current flow to (+) or from (-) the battery typically in amperes. When generators were replaced with alternators, the problem with insufficient output at idle was essentially solved so that the battery was charged even at idle and the "amp gauge" was no longer needed. The battery in modern vehicles is used only when the engine is not running, as in starting or listening to the audio system while parked, or the charging system is defective.

Alternators produce alternating current (AC) and voltage which is converted to direct current (DC) and voltage using solid state diodes. This is followed, as was the old generators, by a regulator to keep the output from becoming excessive. Old style regulators were separate items, but are now typically part of the alternator. Today's alternators typically can produce 100 A or more of current at 15 V. A typical, fully charged battery will indicate 12.5 V under no load. Most car electrical parts are rated at 13.8 V. This is the average voltage most devices will see in a car system in which a partially charged battery is being charged and the rest of the current from the alternator is being used to run the system. As conditions vary, so will the alternator output and the system voltage.

This is very short primer on low-voltage systems (now 12 V - they used to be 6 V) as typically found in today's cars. If you have any more questions post them here.

thank you TedC, that was very easy to comprehend. i know that in restorations, many times the generators are replaced with alternators, such as in old Harley Davidson MC, i understand why now.

I am still suspicious that my 2006 DTS has a charging issue. do these cars have some type of 'assisted' starter motor? when I start the DTS with the ignition key, i only have to touch it the key to the start position, and then it seems that the starter takes over and goes on spinning. knock on wood, the car starts every time, but sounds like a weak battery none the less.

i have owned the car for the summer now, and its great. just got back from a trip to Daytona/Orlando and have several day trips to Lexington VA also this summer. Looks good, rides great and plenty of torque when desired on the highway.

RSD, ya know your car could have a build date in 05. Your battery may be close to five years old. Could be you may need a new battery. Starting your car is the heaviest load you can put on a battery.
Bob

Don't stare at your voltage readings on these newer cars.
If something is broken a red light will come on, staring at the voltage can cause madness.

These systems use pretty complicated software and sensors to control charge rate and battery state of charge. Lots of stuff is taken into account including the temperature of the battery.
The voltage will normally flucutate all over the place. 12.8 to 14.x is all perfectly fine.
These are externally regulated by the engine controller, some use other modules to help monitor the state of charge for the battery also.

Thank you gentlemen, all very good advise for a new DTS owner.

EWill3rd, turns out i bought this used certified 06 DTS L3 at Lindsay in Alexandria. one reason i went back to Lindsay to purchase was the fine treatment i received when needing work on my 10 year old Eldorado last year and this year. Thanks to all for your help.

i will put a new battery, hopefully in a week or so. with the daily commute to DC, etc, i have decided to eat this one, and not ask the warranty to cover the battery, still not sure if its bad yet. Heading out to Lexington VA again this weekend, and am keeping a portable jump start box in the trunk, plus cables.

The correct word is "advice," not "advise."

On the DTS the battery goes under the back seat.
I think it is a 79 series battery. You need to be sure to put a battery in there that is properly vented and the correct size. I am not sure I know of many aftermarket batteries that meet those criteria.
All batteries produce gases when they charge, if the battery you install doesn't have the vents that mate up to the hoses back there those gases will vent into the passenger compartment.

We are still here if you need us.
I know we keep those in stock.
Are you out of warranty?
The factory warranty or certfied warranty will pay for battery replacement.

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OK, i'm convinced, I will run it up to see you at Lindsay sometime this month for a battery check. just have to juggle my son starting college and a gruesome commuting schedule. Thanks for the support, all, and Advice, Scott

I feel your pain.
I am glad to offer advice when I have some to give.
We'll be here when you are ready to have it checked out. ;)

Reply to RSD on issue of starter continuing to grind even after letting key return to 'run' position. This is automatic feature of remote start. Key switch acts the same as remote start. It will grind until starting and then automatically stop the starter motor. I think the owner's manual mentions this.

The correct word is "advice," not "advise."

Is that true if you are using a generator instead of an alternator?

Your elem school teachers would be proud of you. H S too most likely.

Hi all,

I suspect I have a battery problem on my 2006 DTS Performance.

On 2 recent occasions now I have been unable to start my 2006 DTS as follows:

1) I re-activated my XM radio subscription and they said to leave the car in the driveway with the radio on while they downloaded the activation code. They said it would take up to 30 minutes. I turned the key to the first detent so that only the nav/radio was on. No headlights, no dash lights, doors closed, etc. After about 20 minutes the XM activated. Then I went to start the car but the battery was toast. I put a charger on it and started it about 10 minutes later and put it back in the garage.

2) Today, I was in the carwash lineup. There was 1 car ahead of me. I turned off the engine and had the key in the first detent to just listen to the nav/radio. Once the wash bay was clear I went to start the car but the battery was dead. again A guy in the lineup next to me gave me a boost. (embarassing)

I've only had this car for about 2 weeks. I've read about TSB 1906368 (BCM reprogramming), ground lug connections with paint on/under them, Onstar modules calling home too often, corroded BAT+ connections in the engine compartment, etc. but to me this just sounds like a weak battery.

So basically, I don't think my battery should die after listening to the nav/radio for just 15-20 minutes? I have noticed though that the screen gets fairly warm.

Also, does anyone know approx. what the parasitic load should be on my battery (milliamps) when the key is out of the ignition? Perhaps it's draining the battery a bit faster than normal and listening to the radio finishes it off.

Lot's of people on the Cadillac forums seem to complain about battery related issues but like I said, this sounds like the battery itself to me.

The DTS is still on warranty.

Thoughts?


Many thx in advance..............Ron

DTS Dude,

Having a battery die, or having a flat irritates me, no end. :)

Your battery is about 4 years old.
They do have a finite life that varies depending on the conditions they have been subjected to.

I think I would take it to a local auto parts store and have the battery load tested. Most of them will test the battery for free.

If there is ANY DOUBT about the condition of the battery, take it to the dealer and have it replaced under warranty.

I had mine replaced about a year after I bought it.
It went dead in the garage after sitting for a week without being started.

Texas Jim

My 2006 battery crapped out overnight about a year after I bought my DTS new. I drive it every day. Replaced under warranty

Well, I got my 06 DTS into the dealership yesterday. I told them what was happening (see my post above). I told them I suspected a battery issue. The Service Advisor told me that it's normal for the car to not start after listening to the radio for 15 minutes (key in 1st detent position). They said they would check it out anyways.

I came back 2 hours later and the car was ready. Service Advisor said everything checked out and that they did not replace the battery. I wasn't too impressed but what could I say. They checked it out. When I got home I decided to make sure the tech put everything back together properly and tight. When I removed the back seat I noticed right away that it was a different battery ???. I had taken photos prior to the trip to the dealership so I checked my camera. Sure enough it was a different battery. I checked the paperwork (for the 1st time) and it said "Battery tested no good. Battery replaced". ??? Now I'm happy again but why would the advisor say they didn't replace it?

The battery voltage on the DIC seems more stable now at 14.5 volts. Only way to know if it's fixed is to run the radio/nav unit for 15 minutes and see if it still starts.


Cheers.............DTSdude

Delco batteries are superb at holding a "surface charge".
If you run the radio for a while it will quickly drain a weak battery and make it not start but once jumped or charged it will last for a while.
The battery is still likely bad but it appears good because of this characteristic.
Maybe the advisor was just clueless... but you got it fixed... that is good.