Just wondering what you guys are getting for battery voltage? Engine off and Engine on. Actual readouts,not guesses.. Any of you guys with E55s and E63s

Had my battery checked, they hooked it up on machine ran tests and said it was fine. But, it hasn't been changed in awhile since 07 or 08. I thought it would need to be changed. But, they said it was ok. So is it?

Engine off = 12.0-12.3 volts

Engine on = 13.8 13.9 volts sometimes flickers to 14 volts


I asked them to put in a brand new AGM battery and we checked and voltage was only .1 volts higher then my battery. Not sure if I needed to drive it around and check again. BUt it we did right in the parking lot. What gives?


Not sure if I'm just being very picky. Maybe thinking I need to replace the voltage regulator?? (BUT, It was already done under warranty)

I always keep my car in tip top shape and it's the reason why I feel it always runs so well and has treated me good throughout the years.

 

Voltages look normal to me...

 

Would you be able to check one of these days just to compare? And possibly chime in this thread. It would be nice to know what others are seeing voltage wise. Engine off and Engine on.

 

I would just change the battery... It's 8 years old

 

What was the temperature? If you google battery state of charge chart, you'll find several and most of them say 12.7 volts is fully charged at 78 degrees. The new one you put in could have been sitting on a shelf for a while and might not have been fully charged. If you drive it around for a while, it will charge up the battery, but the reading you're supposed to go by is when the battery has been sitting a while not under load. Of course when it's just been charged, it will read higher for a little while. On my E350, it ranges from 11.7-11.9 and it's also 7 years old, but it's also about 30 degrees outside. At idle voltage ranges from 13.8 to 14, but while driving it, it can go as high as 14.2. AGM batteries can last longer than regular flooded batteries, they seem to average about 8-10 years and some people have gotten more out of them.

 

Battery and regulator look good!!

 

Yes, The temperate was about 73 degrees or so. Ok so your's is about the same as mine. That's a relief.

My current battery is OEM AGM battery. I have heard they last a long while. Substantially more then normal wet cell batteries whatever they are called.

Everything works just fine on the car. I wanted to change it but, the guys at the shop told me I don't need to. They tested it with my car on and off, said it was fine. So, I guess its fine.

I'm going to start hooking my battery up to the trickle charger I just got to keep a fresh charge when I'm not using the car.

 

Looks good to me. Those are the values I see on my car

 

OK, Then all is well in my world… Thanks for your input.

 

Im having this problem on my S211 dont no if its normal or if its any problem with the voltage regulator

The battery has only 2 years, I no that it used to go to 14,2 volts in idle, but this week I got only once the following message "Battery Protection: Convenience Functions Temporarily unavailable"

It hasent appear any more but it only goes to 13,9 and oscillates between 13,9 and 13,8 is it normal?


Sorry for the video that is in Portuguse, but first two photos is with key on only, when the video starts running is with the car in idle.

 

Looks fine to me. Mine does the same on occasion. same Voltage as yours.

You might need to change your AUX battery under the hood. That is what controls the convenience functions.

 

Isent the AUX Battery only for the SBC unit, I think so.

And 13,8 volt isent that great since it should allways be on the 14,2 volts, at lest I used to have the 14,2 volts at idle , but since it appeared the convenience functions deactivated it only shows 13,8 volts.

 

Sounds fine to me . But as you said , if you don't drive it daily then get a battery tender and throw on it . Especially during winter time.

 

I dont have garage to have a battery tender , my wagon sleeps in the star garage, outside

 

No it's not just for SBC, it is for convenience functions. When the AUX battery goes low the convenience functions stop working. to save battery life for SBC brakes.

 

Ok, but could you tell me if its normal that the voltage is inconstante, and not fixed on 13,8 ou 13,9 volts.

 

I just checked mine for you. It's always on a battery tender, the Deka AGM(850AH) battery is 5 years old. Car off=Position 1 ignition shows 12.2v. Position 2 (with vent fans running) is 12.0. Car idling=13.9, 2000RPM 14.2. Hope that helps. I too think yours is OK.

 

Hey Max..... Since you checked your battery I went and checked my main battery and got a reading when it's off at 12.4v so I'd say we are similar on that level

HOWEVER

Here is MY question to you. When you drive your car say for 30 minutes and go back to turn it on does it have a hard time cranking? Like if the battery is low on voltage? turns on but it struggles. I have that problem and I can't find the solution. Dealer mentioned my starter was pulling too many amps. hhmmmm I was wondering if they were diagnosing that correctly or making me spend

Your thoughts?

 

Do you have the OEM battery? If it's taking longer to start, it may be a sign that the battery is starting to go. Only way to tell is to take it to an auto parts store and have them do a load test on it. Also if you check the voltage when you just turn it off, the reading will be higher than if you let it sit overnight and check it first thing in the morning before starting it.

 

Well my car in Idle doesen't gets to 14,2 voltas thats why I think there is a problem, I now that last year when I was cheking the voltage it was always on 14,2 volts but now it only gets to 13,8 volt and some times less.

Well yesterday I did again the teste and it dosen't seem normal, if it was it shoul at least always stay at 13,8 volt, and some times it does some times it doesen't

Look wat was yesterdays the max of voltage I got was 12,3 volts at Idle

https://www.youtube.com/watch?v=l5sr...ature=youtu.be

 

12.3 at alternator or battery? If battery is toast the load will draw voltage down at battery post read. 12.3 at alt. different story.

 

I think that you didn't see the last video I posted, because you would see that its the voltage of the alternator.

 

Did not see that...my apologies! Alt should be over 14v and I've had a few pre-game playoff drinks to boot so bad time to post I suppose.

 

no problem, yes I now that it should be over 14 volts but now some times its on 13,8 volts other times its 12,3 volts

its my be the regulator tension dont you think?

 

No, it turns on just fine. No struggling 30 minutes or overnight. Hmmm did you have your battery load tested?