Hello everyone, I just found this thread on the new Impala charging system voltages and am also very interested in the topic. So, I just now registered for the forum and trust it will be a good experience. As mentioned earlier in this thread (-I guess that's what it's called,,) I also am finding this topic to be very informative, and certainly wish to learn just what is going on with our new 2015 Impala, as it relates to the battery voltage as displayed on the DIC display. Thank you Thomas for starting the topic, and Tech2 for the numbers you have given us. And I fully appreciate the concept of "the computer" is now doing a much more sophisticated job of battery maintenance than what any of the older models did.

Currently it is my concern that my 2015 may not be holding the voltage high enough. Granted when first started it does read that 14-point-something for what seems like a minute or so, but honestly I haven't timed it, so it could be only 30seconds. ANYWAY, it then drops to that 12.5 volt reading and seems to just stay there forever. I'd like to see it stay at least in the 13's for my own comfort, but hopefully "the computer" is smarter than me.

Now I'll also readily admit that we only have 600 miles on it, so I need to make some road trips to see if maybe the voltage will creep up to a better number after an hour or two on the road.

I also have used the Battery Tender brand units for quite a few years, and after reading all of their technical info on their website, I feel very confident that they really do have the correct solutions for long term battery health. I am 100% satisfied with Batter Tender, and have now purchased the "Plus" model (which has a 1.25 amp bulk charge mode) for this Impala. I have attached a digital voltmeter and observed the three very distinct cycles that it goes through. When it goes into it's final mode of long term maintenance ("float") it stays rock solid at just a touch over 13 volts.
So with that, I'll stop rambling on for now, and await your replies.
Thanks so much, 57chevythunder.

 

-just a quick side note: Say "tech2" would you mind telling me how can I find the lengthy detailed technical data from which you extracted the numbers you shared with us? Honestly I, for one, rather enjoy pouring through pages of technical details on a topic. -in fact I will be spending the $200 from Helm Inc as soon as they release the genuine shop service manuals for this 2015 model. I certainly understand your wisdom in not keying in pages of data which may bore the average person to sleep, but for us others, just let us know where we need to go so we can wade through the details. THANKS!!

 

Honestly - you all are over thinking things and worrying about nothing.

How many accessories are you running when checking voltage? Running AC/blower motor full speed/wipers/AC outlet will put more strain on the system.

Anyways - volts don't charge a battery. AMPS do.

 

"worrying about nothing" in my case is probably a fair statement, since according to the data supplied by tech2 12.5 seems to be normal under that particular running condition. And yes, being retired now, I probably have more time to "over-think" things.

It sure does seem apparent that GM is now using a rather complex algorithm in the ECM to make it much "smarter" as it pertains to battery charging as well as the system operating voltages under various conditions. -thanks again tech2 for supplying the numbers.

ThomasM, if your system voltage really is continuously that high, under normal daytime running without having a lot of accessory loads drawing current, then I think you definitely have a realistic concern. I guess if it were me, I'd pay a visit to the service dept at another dealer or two, and see what they have to say about it. Here is another thought I have in your case: I wonder if the battery in your car is still in a "sulphated condition." After all, the first 8 or so weeks of a new car's life is pretty brutal on it's lead/acid storage battery. -besides that, the battery is probably even older than that, and has set around without any charging at all until the car is assembled. Have you driven your car for any long distances yet?

Also, for everyone who may want to learn some of the science involved in proper lead/acid battery maintenance, here is the link to the battery tender website: Battery Basics
They have done an excellent job in providing some applicable technical information.

By the way the original battery in my 2002 Bonneville lasted a solid 11 years !! -and I give a lot of credit to using the Battery Tender Junior on it every time it was parked in the garage. (which was most of the time)

Also, proper battery maintenance is certainly NOT as "simple" as some might think. The methods of re-charging the battery in older vehicles was "minimally adequate" at best. Additionally, the mere fact that the battery has to live under the hood, suffering from extreme temperature swings etc, makes the task even worse. -the fact that the battery in my Bonneville is under the right rear passenger seat no doubt adds years to it's life.

Thanks again to every one for your input !! -and I hope several of you will appreciate the data on the battery tender website.

 

I take too many short trips and burn out batteries after 3 years. Even an Optima Red Top was toast after 3 years. I think another Optima Yellow Top I have in another car is starting to become toast.

I don't remember seeing battery charge level in the DIC on the Impala.

So I guess I get to ask them dumb question - how are you examining volts when driving around?

 

sledge, I see your car is the '14 LTZ, so you should definitely be able to see battery voltage as one of the info pages in the DIC stack. If it is not there when you scroll through the pages, then I bet it is not "turned on" in your "settings" menu. Here is a brief quote from your owners manual:
DIC Info Pages
The following is the list of all
possible DIC info page displays.
Some items may
not be turned on by default but can
be turned on through the Settings
app. See “DIC Info Page Options”
earlier in this section.

After you get this set up, I will be super-happy to read your reply giving us the numbers you see on your car. The condition I'm most curious about is what the voltage reading is after a few minutes of driving, daytime (no headlights, only DRL) and just normal accessories running.

I'm sure you will find that when you first start the engine and drive away, the battery voltage will read in the 14's for a short while, maybe a few blocks. Then it will drop back to maybe 12-point-something and stay rock steady at that number. With mine, I have experimented with turning various accessories on and off, and the reading on mine still stays rock steady at 12.5. (which does tell me that the "voltage regulation" aspect of the system is probably working perfectly, but just set a little too low.)

The whole point of my concern is that for the long term health of a lead/acid automotive battery, it must be "floated" at a level of about one or two volts above 12.6 volts. (precisely the reason these after market battery maintenance devices often extend the life of a battery by a very impressive number of years by keeping it out of the "sulfation" zone.)

Anyway, be sure to reply back and give us the numbers of your readings.

And for others reading this post, please reply with your readings too !
THANKS!!

 

Thanks, will check it tonight just to ease your mind that's all well.

 

Ok - Found it in the settings and enabled it.

Turned on car - 15.x... while driving rock solid 14.4 to 14.6.. mostly 14.5. With or without accessories, at 33F degrees on the media console.

When in park with all accessories turned off 15.3V.

Of course, I am at 4,667 miles after 14 months.

I also noticed in the owners manual, on 5-30, about "vehicle messages".. battery saver active, low battery, service battery charging system.


If I were you, I'd compare idle voltages with a volt meter and see if your DIC is off by a couple points.


I made some videos, but I'm sure they will be terribly boring. I'll upload later on and post.

 

Sledge, thanks again. -good info. And you are right, I shall use my digital voltmeter (hand-held test equipment meter) plugged into one of the power points and do some comparisons, hopefully one of these next nice-weather days soon. I'm certainly still early in the learning phases of this new smarter technology now used by our new Impalas.

It just may be that the solid 12.5 readings I was getting the other day on my 45 minute short trip was caused by the battery being already fully charged (due to the battery tender) and also fairly light accessory loads.

Anyway, for my own curiosity (and peace of mind) I shall continue to observe, test, inquire, and learn. And I will be sure to pass along any pertinent data I may acquire.

Thanks Again !!

 

Hey, ThomasM -are you still "on board?"