When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hi,
quick question about battery voltage.
I just bought a 2013 carrera base and the battery died in a day so they replaced to a new OEM battery.
but it still reads only 12.3-12.4 when I turn the ignition on. It will go up when I start the engine about 13.6, when I drive at 20mi it hits 14.5. I heard it needs to be over 12.6 when turn the ignition on. But still, is it normal for 911 to lose it’s battery in a week if you don’t drive?
Doesn't sound like a tech for a 100k car...
I don’t think I cam ignore it since the number projects the life on the battery. Will your car go dead if you don’t drive it for 3 days ?
probably in Fairbanks in mid winter....the greatest predictor of battery life is the calendar. I routinely do not drive my car every day - sometimes I don't drive it for a week - and since June 15, 2012 the battery has survived to start the beast.
I did replace a 6 year old OEM battery with a Duracell AGM...it's just fine.
Should be able to go at least a couple of weeks without a charge and start the car. For peace of mind get a maintainer. Once the car is started what you are seeing is alternator output which will depend on what load it's dealing with at the time. Only a small part of it is battery recharging.
In addition to everything else, the voltage reading also varies with temperature. There is a temperature sensor in the negative battery terminal cable clamp. Batteries are harder to charge when they are cold, so the computer increases the charging voltage when it senses that the battery is cold.
All we do is batteries though we do lightweight Lithium-Ion for performance vehicles instead of Lead/Acid.
What many people said above is accurate.
1- You had and old battery and bought a used car. So battery died. It should not be relevant to your new batteries performance.
2- You should get a minimum of about 4 weeks if not 6-8 weeks from a 991. I have tested that a bit since I have a 991 variant and tested our Lithium Batteries in it. For a 30Ah battery we get about 6 weeks of storage... you should actually get longer with a new big Lead/Acid battery.
3- Lead/Acid resting voltage is 12.6~12.8v... when you first turn on car it will drag it down a little as you system turn on... then when you start it the Alternator kicks in raising the voltage... then you will see it vary a bit from low 13s to high 14s.... don't worry about it, that is just what it does and it charges the battery and provides power to they cars systems. It will vary quite a bit due to a number of conditions... if you have lights on, AC on, temperature and more.
If you're into watching your battery and want to know how long it will sit in the garage and not over-discharge or if you want to know the voltage without getting in the car we've got something you might like and find very helpful.
Its called the Battery Tracker. Its a Bluetooth Voltage Tracker and it will monitor your voltage and all your charging, starting and any other voltage data over the course of 31 days and display it on your phone. You don't even have to get in your car to see the real time voltage... its all on your phone. Real Time and Historical Data.. So you will see if you have a fast parasitic drain on the car, see when you started the car and what voltage it is charging at when you stopped the car. If you're on vacation you can see if anyone was driving your car because you can check your Battery Tracker and it will show if the voltage indicates if it was driven while you were away.
Long story short, by the time you get a reading from the dash voltage indicator, many computers and other system are already energized and depleting the battery - hence your low indicated voltage ! Mine read 12.2 one day before starting and so I replaced it. When I pulled the old battery and measured it outside the car, that old gal read 12.7 !!! ha ! Also note in sports mode the alternator will charge more vigorously and you will see 14V, maybe 15 at times, doesn't mean much...
I ended up wiring a CTEK charger plug (with a rubber cap) on the battery that exits top of the front trunk by the wipers.. I can measure my true voltage there without opening the car and sucking electrons. It's fine and higher than what the car says when I put the key in the ignition. That said 991s IMO suck a lot of juice so replacing a battery and putting the car on a a maintainer is a great idea.
All we do is batteries though we do lightweight Lithium-Ion for performance vehicles instead of Lead/Acid.
What many people said above is accurate.
1- You had and old battery and bought a used car. So battery died. It should not be relevant to your new batteries performance.
2- You should get a minimum of about 4 weeks if not 6-8 weeks from a 991. I have tested that a bit since I have a 991 variant and tested our Lithium Batteries in it. For a 30Ah battery we get about 6 weeks of storage... you should actually get longer with a new big Lead/Acid battery.
3- Lead/Acid resting voltage is 12.6~12.8v... when you first turn on car it will drag it down a little as you system turn on... then when you start it the Alternator kicks in raising the voltage... then you will see it vary a bit from low 13s to high 14s.... don't worry about it, that is just what it does and it charges the battery and provides power to they cars systems. It will vary quite a bit due to a number of conditions... if you have lights on, AC on, temperature and more.
If you're into watching your battery and want to know how long it will sit in the garage and not over-discharge or if you want to know the voltage without getting in the car we've got something you might like and find very helpful.
Its called the Battery Tracker. Its a Bluetooth Voltage Tracker and it will monitor your voltage and all your charging, starting and any other voltage data over the course of 31 days and display it on your phone. You don't even have to get in your car to see the real time voltage... its all on your phone. Real Time and Historical Data.. So you will see if you have a fast parasitic drain on the car, see when you started the car and what voltage it is charging at when you stopped the car. If you're on vacation you can see if anyone was driving your car because you can check your Battery Tracker and it will show if the voltage indicates if it was driven while you were away.
My voltage reads 12.3- 12.4 when only ignition on.
I just replaced my battery and it’s still lower than 12.6.
Putting it simple, I left my ignition on for about 10 minutes and the battery went dead. This means I cannot turn ignition on anywhere I go, in case I just want to listen to music with engine off, or fan on without AC on. Is this totally normal? My Macan does not have any of these issues, and seems like a lot of people using the battery charger which I assume they have similar problems. But even with a charger you cannot use it outside of the garage...
My voltage reads 12.3- 12.4 when only ignition on.
I just replaced my battery and it’s still lower than 12.6.
Putting it simple, I left my ignition on for about 10 minutes and the battery went dead. This means I cannot turn ignition on anywhere I go, in case I just want to listen to music with engine off, or fan on without AC on. Is this totally normal? My Macan does not have any of these issues, and seems like a lot of people using the battery charger which I assume they have similar problems. But even with a charger you cannot use it outside of the garage...
If we're really talking only 10 minutes here, No, this seems extremely excessive and there shouldn't be a draw large enough to discharge the battery that fast. Any aftermarket items installed on the car and out of curiosity did you have the old battery tested prior to replacing it with the new one? While there's the possibility of a bad new battery it might be a good idea to get a meter, dig in and start doing some testing on draw to see what's going on and what it is that's pulling power when the ignition is not on as well as once it's turned to the on position.
All we do is batteries though we do lightweight Lithium-Ion for performance vehicles instead of Lead/Acid............
If you're into watching your battery and want to know how long it will sit in the garage and not over-discharge or if you want to know the voltage without getting in the car we've got something you might like and find very helpful.
Its called the Battery Tracker. Its a Bluetooth Voltage Tracker and it will monitor your voltage and all your charging, starting and any other voltage data over the course of 31 days and display it on your phone. You don't even have to get in your car to see the real time voltage... its all on your phone. Real Time and Historical Data.. So you will see if you have a fast parasitic drain on the car, see when you started the car and what voltage it is charging at when you stopped the car. If you're on vacation you can see if anyone was driving your car because you can check your Battery Tracker and it will show if the voltage indicates if it was driven while you were away.
So I installed one of these Trackers (Lead/Acid version) on my 6.8 year old OE Porsche battery (Banner H6), as I want to watch it's condition more closely due to its age. The battery is still strong, with the Tracker reading a resting voltage around 12.7 volts and indicating "100% Battery OK" . Since I'm paying more attention to it, I've noticed that on a cold start (battery/car resting for 12 or more hours), the dash system indicates a Charging Voltage of ~12.5 volts after starting, and will stay there for about 30 - 45 minutes of drive time, then will increase to the 13.5 - 14.5 Volt range.
After the initial install, with the car sitting over night, I tried the "Crank Test" function which states "Automatically Tests Each Time Vehicle is Started", yet my Tracker does not..... and only shows the resting voltage from when I originally installed the Tracker. So something is "Frozen" there, or I do not know how to have it display the latest information on the Crank Test Screen? The Battery Voltage Monitor shows the Voltage Drop at Start (Crank), yet not on the Crank Test Function Screen. I possibly need to disconnect & reconnect the Tracker (I.e. reboot the unit).
I then tried the "Charge Test" function of the Battery Tracker, and after the cold start it said that the car was not running and I needed to Start it, when it was actually running at idle. Charging system on dash and on tracker displayed 12.5 volts, So I "guess" (which is usually bad to do), that the Tracker is looking for some minimum voltage above 12.7V to think that the car is running??
The graph below shows the Battery Voltage over time. I installed the Tracker on October 16, about 3:30pm. So this graph starts the next day (Oct 17th).
The Time Axis scale is in Hours, and I do not know the data point frequency, so it may not show all events.....
This device can be useful, if it was fully functional. I'll try the "reboot", and report back.
If the folks at Antigravity have any input, it would be welcome!
Update on my Antigravity Battery Tracker: I performed a "Reboot", by disconnecting the Negative terminal from the battery, waited 45 seconds and reconnected.
That did the trick! All functions on the Tracker are working now So what have I learned about my 6.8 year old battery?
It is still fairly strong as shown by the 18 hour resting Voltage, after a 25 minute drive home.
However it is Marginal after Multiple Starts in a short time period.....
Initial minimum Cracking Voltage is OK........
However, after a 12 minute drive to the store and resting for 48 minutes while I was shopping,
the Battery showed its age......... (Note that the car Started fine with no issues)
So I will continue to monitor the Battery and try to avoid short trips with insufficient Charge Time between Starts.
Probably time to start looking for Battery Sales this Fall/Winter season! At close to 7 years old, this Battery does not owe me any more and has done its job, and continues to do its job very well!
I would consider a Antigravity Lithium Battery if the cost of their H6 (40Ah) was in the $500 range, or about twice what a Porsche OEM Lead Acid battery costs. Yet at $830, I can't justify the $$.
Sorry I'm a little late on the follow up 981KMAN, but glad the reset did the trick, may have just been hung up or something, but I also imagine we may see some software/firmware updates to increase efficiency and functionality with the release of updated phones and software as of late.
Best regards,
Chad chad@antigravitybatteries.com
06-10-2019, 05:03 PM
Battery Voltage reading
So what have I learned about my 6.8 year old battery?
