Regular battery voltage

I've only had mine for about 3 months but it usually shows 11.8v also

 

11.8is about 35% charged.

12.6v is100%

 

Here’s my state while charging, my car has the AGM (non lithium) battery installed
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Wondering if the lower voltage level of 11.8V is seen when unplugged. Now that I have the app working, I'll be able to monitor things.

 

Check your battery to see if you have a Lithium or AGM. Passenger footwell, there's two thumbscrews and battery cover comes off.

 

My battery is always at 11.8v and I drive my car often. There was another thread about this and I mentioned it to the service manager at BH Ferrari. He told me they had troubleshooted it and the actual battery measures correctly, but at the sensor it reads 11.8v due to some sort of wiring/chip/relay ( I forget exact words ). He says normal.

 

As an FYI, for a lead/acid Battery your resting voltage should be 12.6v if in a good state of charge, Lifepo4 (LFP) will be 13.2v. Those are the nominal/resting voltages of those types of battereries after having being charged and settling back down to their resting voltages. As an FYI, even if battery are charged to above thier resting voltage by the alternator, or a stand alone Charger, for example 14.6v, they will always drop to ther nominal/resting voltage once removed from charging.

To sort of address your question, imagine you go to your 296 and get in the car and the instrument cluster is showing 11.8v and you thinking.... "my battery is pretty low.." But the fact is that it is that display is NOT the actual voltage of the battery. This is because you did not notice that by opening the door you have made the Car "turn on" to get ready to be driven. So what happens is the computer awakens, the interior lights go on, and other systems start doing there thing, so all those devices were trigger to go on and create a "load" on the battery which creates a voltage sag because energy is beging drawn from the Battery. Yet in reality if your battery was not subjected to those loads from opening the door you voltage would be at 12.6v. So often you can get a LIVE reading by looking at your voltage on a Cars display, but it is not the actual voltage the battery would be at if just resting.

Below is a screenshot I just took to demonstrate what I said above. This screen shot if from a cool device we make called the Battery Tracker that allows battery voltage and other data to be shown real-time and historically on the Battery Trackers Bluetooth App. So this image depicts how I am reviewing a real-time voltage data and in the Graph at the bottom of the app you will see a straight line showing the voltage at about 12.6v, that is when I am outside the car and looking at the app, then you will see a immeidate voltage drop when I open the doors to the 296 and the screen and other devices in the car wake up. So if I am trying to read my voltage from the Car screen or app when I have opened the doors of the Car the actual voltage for the battery will not be accurate, and you will be reading a voltage while the battery is under a load, which does not really reflect the true voltage the battery might be at. See the red arrows in my image.

Also note below I post another image that shows the 296 Plugged into its Hybrid Charger. You will see hours on the bottom of the graph starting at 12 midnight then showing a 24 hour day. So the Low Voltage Battery is charged when it drops to about 12.7v and the High Voltage Battery starts the Charging again, but it is a constant profile roughly every 9 to 14 Hours as show in the image. But keep in mind this same profile exists even with the Charger not plugged in, this is because it is the High Voltage Batteries capacity that is then charging the low Voltage Battery. Also of note is you will also see a large drop in voltageat about 3pm, and that is when I'm cleaning the cars with the door opens so the load from the system being ON is causing the voltage drop... then I go for a short drive immediately after and you see the voltage spike after that drop..... Also note that those plateaus of higher voltage are the LV being charged at 14.9v by the HV Battery for about 45 minutes then it turns off and the voltage starts dropping to nominal, and the process continues until you run out of high voltage battery capacity and discharge both the batteries, and your sort of jacked, as I recently did.