Anyone successful at using a Smart 12V charger on a Model 3?

[rrolsbe]

I have read many posts regarding using a battery tender/smart charger to maintain the 12V battery on the Model S but has anyone had any success doing this on a Model 3? I instrumented my Model 3 and tried to get my NOCO G7200 to keep the 12V AGM battery topped off. I tried several settings over a 14 day period and could never get the G7200 to top off or maintain the 12V battery. The phantom drain was still around 4 miles a day over this test period (ie.. no change). I monitored the G7200 charger power usage over the 14 day test period using a Kill-O-Watt meter (almost no power used). While sleeping, the Model 3 seems to draw around 0.5 to 0.6A from the 12V battery. Does anyone have statistics on what average power draw is while the Model 3 is sleeping? If accurate, that would be less than about 8W average but would need to supply approx 1KW of power from the wall to replace that 12V power draw (that is around 42W). If interested, I can supply more details about my experiment. There has to be something slightly different with the 12V AGM battery top off charging logic on the Model 3?

Regards, Ron

PS - The car was not driven and the Gen 2 UMC charger was not plugged in during the 14 day experiment.

 

[ewoodrick]

Why are you trying to charge the 12V battery? Honestly the only thing that I think it would do is harm it.
That's what the built in charger and computers are for.

Yes the car has phantom drain, that's on purpose. It's part of it's design.

Charging of the 12V battery is closely monitored by the computers. Some of the other cars had issues and they've worked hard to fix it. I don't think that I have heard of many, it any Model 3 12V battery issues.
I certainly hope that you didn't park the car for 2 weeks just to run the test.

My recommendation, drive the car, stop worrying about the battery and just enjoy the car.

 

[jjrandorin]

I have read many posts regarding using a battery tender/smart charger to maintain the 12V battery on the Model S but has anyone had any success doing this on a Model 3? I instrumented my Model 3 and tried to get my NOCO G7200 to keep the 12V AGM battery topped off. I tried several settings over a 14 day period and could never get the G7200 to top off or maintain the 12V battery. The phantom drain was still around 4 miles a day over this test period (ie.. no change). I monitored the G7200 charger power usage over the 14 day test period using a Kill-O-Watt meter (almost no power used). While sleeping, the Model 3 seems to draw around 0.5 to 0.6A from the 12V battery. Does anyone have statistics on what average power draw is while the Model 3 is sleeping? If accurate, that would be less than about 8W average but would need to supply approx 1KW of power from the wall to replace that 12V power draw (that is around 42W). If interested, I can supply more details about my experiment. There has to be something slightly different with the 12V AGM battery top off charging logic on the Model 3?

Regards, Ron

PS - The car was not driven and the Gen 2 UMC charger was not plugged in during the 14 day experiment.

I asked a mobile ranger who posted here about charging the 12V battery in a model 3 and he basically said there was no point in it.

 

[Big Earl]

The 12 volt battery is charged by the high voltage battery as necessary. Model 3 standby consumption seems to be about 50 Watts.

Model S was infamous for killing 12 volt batteries for a while due to the charging algorithm that the car used, often times supplying more voltage than 12 volt batteries like to receive. I suspect this has been corrected in recent software updates and does not apply to the Model 3 (no widespread reports of 12 volt battery problems).

 

[miimura]

In order to determine whether a 12V charger should be used on the Model 3, you would have to duplicate the tests that others have done on the Model S. You need to use a data logger to watch the voltage on the 12V battery to see how many times the car wakes up and charges the 12V from the traction battery. The excessive cycling on the 12V battery in the Model S is why the 12V charger is useful on that vehicle. Even on the Model S, it's only significant if you don't drive it every day.