12v battery question

12v battery question

I added a subwoofer and where it was done they wired the woofer to the 12v. battery. now I'm getting a message from the 12v battery being drained. does anyone know if theres another source to wire the woofer instead of the 12v battery or can I upgrade the 12v battery to be able to handle the woofer?

lilbean | 2018年6月16日

I’ve heard of this happening. There is no upgrade to the 12v battery that I know of. I’ve heard that some are wiring to an external battery supply instead of connecting to the car’s 12v. It’s unfortunate. This is not an issue in the Model S or the Model X.

ReD eXiLe ms us | 2018年6月16日

The installers should have added an accessory 12V battery of their own to their custom project.

Itrnhds | 2018年6月16日

thanks, I'm gonna call first thing on monday and see what they could do

Coastal Cruiser. | 2018年6月17日

Please let us know the outcome. Even if an auxiliary battery is installed it must be charged, so perhaps you would be back in the same boat. It would be interesting if you find out what is triggering the message, since the battery provides power to other devices as well. Perhaps there is a threshold on current flow.

Keep in mind that another potential place to tap is after the DC-DC converter that makes 12 volts from the high voltage traction battery. Plenty of power there, but likely not tenable because I suspect the contactors have to engage to fire up the converter. But if you're only running the subwoofer when the car is on...

There have been some other threads where people posted where they tapped in. If the posts can be found. If you come up with a solution I will update the MODEL 3 FACT THREAD with the info so that others can benefit.

jdwil | 2018年6月17日

Could it be that because it is connect to the battery and it is always drawing some power even when no music is playing? It might have to be connected to a 12volt that shuts off with the car. To do this you might have to have a relay installed that comes on when the car turns on.

djharrington | 2018年6月17日

It’s likely that the car meters all sources of power draw. It should have this ability since it uses digital “fuses”. Likely, your subwoofer is triggering the message because the car doesn’t meter that energy depletion since you’re pulling directly off the battery. I’d imagine a fix would be to add an auxiliary battery and charge that battery with another circuit from the car (e.g.: cigarette lighter circuit, etc). That circuit will be metered and the car will expect the consumption. Just my guess, fwiw

syclone | 2018年7月1日

The Subwoofer has to be wired to a switched supply. Unless it's turned off it will continue to draw power and deplete the 12 volt battery, even while the car is off.