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12V battery what is the use

Tam

Well-Known Member
Nov 25, 2012
11,291
10,331
Visalia, CA
besides using for an old charger for the smart phones...why do I have a 12V in my new car? And what will I use it for in the future?

12V is very useful:

.Portable inflator & and other power tools (12V jack, 12V impact wrench for a flat tire on the road)
.Portable Stereo: Your A/C can continue to work but your built-in stereo will timeout so you need Sentry Mode to run your 12V portable one.
.Portable TV
.Portable kettle
.Portable stove
.Portable refrigerator...
 
12V is very useful:

.Portable inflator & and other power tools (12V jack, 12V impact wrench for a flat tire on the road)
.Portable Stereo: Your A/C can continue to work but your built-in stereo will timeout so you need Sentry Mode to run your 12V portable one.
.Portable TV
.Portable kettle
.Portable stove
.Portable refrigerator...
thanks for the info. Kind of thought these were the uses. I don't plan on camping or living in my X so I still can't see the use for me specifically.
 

boaterva

Well-Known Member
Supporting Member
Actually (lol) a lot of the parts in the car run off 12 V. I believe the idea was to get rid of it totally but they finally didn’t. The Y may not have one but since 75% of the parts are the same as the 3, maybe it will?

Wonder if the pickup won’t have a 12 V?

It’s definitely a weak point since it has to be replaced every two years or so (just had my X’s replaced (under warrantee, of course)).
 

ewoodrick

Well-Known Member
Apr 13, 2018
5,285
4,292
Buford, GA
besides using for an old charger for the smart phones...why do I have a 12V in my new car? And what will I use it for in the future?

I'll second everyone else's statements. The entire car runs off of 12V. Pretty much the only thing I think that doesn't are the wheels and possibly heater core.
The 12V accessory outlet is for all sorts of items. The USB ports are slow charging, for example, if you want faster, you need to use a aftermarket 12V USB charger.
 
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I'll second everyone else's statements. The entire car runs off of 12V. Pretty much the only thing I think that doesn't are the wheels and possibly heater core.
The 12V accessory outlet is for all sorts of items. The USB ports are slow charging, for example, if you want faster, you need to use a aftermarket 12V USB charger.
am I understanding you correctly, that the car mobility is "driven" by the batteries under the seats and anything else like dash lites, wipers radio is powered by the 12V..that seems hard to believe
 

Tam

Well-Known Member
Nov 25, 2012
11,291
10,331
Visalia, CA
am I understanding you correctly, that the car mobility is "driven" by the batteries under the seats and anything else like dash lites, wipers radio is powered by the 12V..that seems hard to believe

Correct!

400V Main battery powers:
HVAC,
Heater
Drive Units

12V powers the rest:
Lights
Audio
Screens
wipers
Powered brakes (without power, you can still mechanically brake but harder)
Powered steering (without power, you can still mechanically steer but harder)
Battery Management System (no 12V means no way to charge the main battery)
Small motors/solenoids/electronic latches: for seats, windows, doors...
Accessories...
 
Correct!

400V Main battery powers:
HVAC,
Heater
Drive Units

12V powers the rest:
Lights
Audio
Screens
wipers
Powered brakes (without power, you can still mechanically brake but harder)
Powered steering (without power, you can still mechanically steer but harder)
Battery Management System (no 12V means no way to charge the main battery)
Small motors/solenoids/electronic latches: for seats, windows, doors...
Accessories...
ok then! First thanks for quick response. Where is this 'fella' stored..I am assuming it is what is normally charging a ICE ..that large? and how long is the warranty?
 

Tam

Well-Known Member
Nov 25, 2012
11,291
10,331
Visalia, CA
..that large?...

Model X's 12V battery doesn't look that big. It certainly looks smaller than my former Ford Escort's.

...stored..

The 12V battery is located under and between your 2 windshield wipers (after you take out the frunk tub and its HEPA filter):


Gti0oMT.jpg



...warranty..

12V battery is considered a consumable item just like your tires or your windshield fluid. However, Tesla has been covering it under the warranty in the past but I don't know whether it will continue to do so in the future.
 
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Model X's 12V battery doesn't look that big. It certainly looks smaller than my former Ford Escort's.



The 12V battery is located under and between your 2 windshield wipers (after you take out the frunk tub and its HEPA filter):


Gti0oMT.jpg





12V battery is considered a consumable item just like your tires or your windshield fluid. However, Tesla has been covering it under the warranty in the past but I don't know whether it will continue to do so in the future.
thanx very helpful
 
ok then! First thanks for quick response. Where is this 'fella' stored..I am assuming it is what is normally charging a ICE ..that large? and how long is the warranty?
The reason the Tesla 12volt is a bit smaller than ICE 12volt is ICE have the HUGE demand of cranking the engine to start, once running, the accessories in an ICE run off the alternator which recharges the battery too. In a BEV there is an inverter that steps voltage down from the big battery to power everything when driving and recharge the 12volt as needed. In a Tesla though when the car is parked it really is much less asleep than other cars so the 12volt drain is much higher when parked.
 
The reason the Tesla 12volt is a bit smaller than ICE 12volt is ICE have the HUGE demand of cranking the engine to start, once running, the accessories in an ICE run off the alternator which recharges the battery too. In a BEV there is an inverter that steps voltage down from the big battery to power everything when driving and recharge the 12volt as needed. In a Tesla though when the car is parked it really is much less asleep than other cars so the 12volt drain is much higher when parked.
Because???
 

Tam

Well-Known Member
Nov 25, 2012
11,291
10,331
Visalia, CA
Because???

Conventional cars do not need to drain its 12V while parking because they don't need to keep a computer alive. So, it has less vampire drain.

On the other hand, Tesla believes in electronics and it keeps its computers alive even when it's "asleep" so its battery drain is much more than conventional cars'.

Sentry Mode uses a lot of 12V power. Your car keeps monitoring and keeps communicating to its mothership looking for a new update, reporting its position and status... Even in its deep sleep, the computer still monitors the temperature of your main battery and automatically turn on heater / HVAC to keep the main battery happy.... All these do drain the 12V battery.
 

Rocky_H

Well-Known Member
Feb 19, 2015
8,154
10,423
Boise, ID
am I understanding you correctly, that the car mobility is "driven" by the batteries under the seats and anything else like dash lites, wipers radio is powered by the 12V..that seems hard to believe
The car has a lot of regular car parts that come from standard automotive suppliers, like for window motors, windshield wiper motors, cigarette lighter sockets, etc. and the auto suppliers don't make versions of those common car parts that run on 400V DC, so Tesla does need to supply a 12V system that can run the regular little accessories like that.
 
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ewoodrick

Well-Known Member
Apr 13, 2018
5,285
4,292
Buford, GA
Conventional cars do not need to drain its 12V while parking because they don't need to keep a computer alive. So, it has less vampire drain.

On the other hand, Tesla believes in electronics and it keeps its computers alive even when it's "asleep" so its battery drain is much more than conventional cars'.

Sentry Mode uses a lot of 12V power. Your car keeps monitoring and keeps communicating to its mothership looking for a new update, reporting its position and status... Even in its deep sleep, the computer still monitors the temperature of your main battery and automatically turn on heater / HVAC to keep the main battery happy.... All these do drain the 12V battery.

Uh, yes they do. How else do you think that the wireless keys work.
You just don't have a detailed battery voltage monitor attached to it.
Other cars have alarms systems as well, just not as high of a current draw as sentry. But the basic Tesla alarm is pretty close to that of any other car.
 
Tesla stays a lot more connected. My 2015 Chevy took a long time to respond to the OnStar app. The Tesla being more awake responds faster to the app. You get into functions like summon, sentry mode drain can be higher.

Tesla also allows a smaller 12volt by being able to charge at any time. An ICE has to run the engine to charge, which I suspect causes legacy manufacturers to design in smaller "standby" electrical loads.
 
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