12 Volt Battery for Tesla – All You Need to Know

The 12 volt battery is used to power all sorts of things on the vehicle. It powers the headlights, fog lights, turn signals, wipers, door locks, seat heaters, etc. The 12 volt battery can be recharged from either 110 or 220 volts AC via the charging port located under the dash.

12 Volt Battery

If you need to know more about 12 Volt Batteries, then this article is for you!

What Is The 12 Volt Battery In Teslas For?

In order to understand why a Tesla uses two batteries, we need to first talk about how electric cars work. Electric cars use two types of batteries: a low voltage battery and a high voltage battery.

The low voltage battery is typically found inside the passenger compartment and is used to provide power to most of the electronics in the car.The high voltage battery is usually found underneath the hood and is used to provide the power needed to start the engine and run the air conditioning.

The reason Tesla uses both batteries is that they want to make sure that their cars always have access to sufficient energy to drive safely.

What Does The 12 Volt Battery Power?

The 12 volt lithium-ion battery provides power for everything on the car except the traction motor(s). The traction motor(s) are what actually move the wheels and propel the car forward. This means that if you were to remove the 12 volt battery completely, your car would not be able to go anywhere.

Different Types Of 12 Tesla Batteries

Tesla offers two different types of 12 volt batteries:

  1. Lithium-ion Battery Pack – These packs are made up of individual cells that are placed inside a protective case. They come in three sizes: 40Ah, 60Ah, and 85Ah. Each cell can hold about 1.2 volts.
  2. Lead Acid Battery – These packs contain numerous small lead acid cells that are arranged in series to create higher voltages. They come in four sizes: 22 kWh, 24 kWh, 32 kWh, and 48 kWh.

Which Battery Is Better?

Both batteries are great choices for electric vehicle owners. However, the lithium-ion battery pack is more expensive than the lead acid battery pack. 

Also, the lithium-ion battery packs have a longer lifespan than the lead acid battery packs.

How Do I Know Which Type Of Battery Is Right For Me?

The following factors will help you decide whether a lithium-ion battery pack or a lead acid battery pack would work best for you:

  • Cost – The cost of the battery depends on what size you need, but generally, the larger the battery, the more money you’ll pay.
  • Life Span – The lifespan of a battery depends on how much power it provides. The smaller the battery, the less time you’ll have to replace it.
  • Size – Most cars require a specific number of cells to provide enough power. For example, most cars require a minimum of eight cells to provide adequate power.
  • Weight – If you plan to tow a trailer behind your car, you’ll want a lighter weight battery.

Battery Capacity

Battery capacity is measured in Ah or Amp-hours. This means how much current the battery can provide for one hour. 

For example, if you have a 12 volt battery with a capacity of 10 amp-hours, it can provide up to 10 amps for one hour.

How Long Does A Lithium-Ion 12 Volt Tesla Battery Last?

In general, a 12 volt lithium-ion battery lasts about 15 years. Keep in mind that this does not include the lifespan of the car itself.

What Affects Battery Life For Lithium-Ion Batteries?

There are many things that affect the lifespan of a lithium-ion battery. Some of them are:

  • Temperature – Cold weather reduces the lifespan of a battery because it causes the battery to lose its ability to store energy.
  • Voltage – High voltage decreases the lifespan of a 12 volt lithium-battery pack.
  • Overcharging – Overcharging shortens the lifespan of a Li-ion battery.
  • Discharge Rate – Discharging too fast also decreases the lifespan of the battery.
  • Charging Time – Charging creates heat, and if you charge too fast you can risk overheating the battery, which can shorten its life.

How Long Do Lead-Acid 12 Volt Tesla Batteries Last?

A 12 volt lead acid battery should last 10 years or more. But again, keep in mind that these figures do not take into account the lifespan of the vehicle.

What Affects Battery Life For Lead-Acid Batteries?

As with lithium-ion batteries, there are many things that affect a lead-acid battery’s life span. Some of them are temperature, voltage, discharge rate, charging time, and overcharging.

What Is An AGM Battery?

An AGM battery is a type of lead-acid battery. AGM batteries cost twice as much as regular lead acid batteries. They last longer but aren’t always practical because you need to get them replaced every year or two.

The good news is that the price of AGMs have dropped pretty consistently over the last two years.

How Long Do AGM 12 Volt Tesla Batteries Last?

An AGM battery should last about five years. Again, this figure does not take into account the actual life span of the vehicle itself.

What Affects Battery Life For AGM Batteries?

AGM batteries have various external components that determine their capacity. The most important one is the thickness of the absorbent glass mat between the plates.

Thicker mats mean fewer plates, so they’re better suited for cars with high horsepower. Thin mats are good for smaller engines where there is little torque. This makes them ideal for vehicles like golf carts or scooters.

Other factors that affect battery life include:

  • Temperature – Colder temperatures reduce the lifespan of an AGM battery.
  • Voltage – Higher voltages decrease the lifespan of an AGM battery.
  • Overcharging – Overcharging shortens the lifespan of an AGM battery pack.
  • Discharge rate – A higher discharge rate means faster depletion of the battery.

Charging 12 Volt Tesla Batteries

A battery charger is used to charge batteries. When connecting the wires, make sure to attach them securely. Usually, the negative terminal is marked “–“ and the positive terminal is marked “+.”

After charging, check the display to see if the battery is fully charged. Remove the cables and disconnect them. Your battery is now ready to be used.

Charging The High Voltage Battery

When you plug into a standard 120V outlet, your car will automatically begin charging the high voltage battery. If you don’t plug in right away, the car won’t start until the high voltage battery has been fully charged.

Charging The Low Voltage Battery

While the car is plugged into a standard 120V wall socket, the low voltage battery will also be charging. In order to get the best performance from your car, it’s recommended that you wait until the low voltage battery is at least 80% full before starting the car.

Why Should I Use A Dual Battery Charger?

There are several reasons to use a dual battery charger. One of the biggest benefits is that it allows you to charge each battery separately. Some people prefer this method because they like to keep the low voltage battery fully charged while the high voltage battery is still being charged.

Another benefit is that some dual battery chargers allow you to set up multiple levels of charging

For example, you could choose to only charge the high voltage battery to 50%, then leave it alone for another hour or so. Then you could switch over to the low voltage battery and finish charging it.

A third benefit is that when you connect the charger to the car, you may notice that there is no resistance between the charger and the car. This indicates that the charger is properly connected to the car.

Do I Need To Be Concerned About Safety When Using A Dual Battery Charger?

Yes! Always follow these safety guidelines when using any type of electrical device:

  • Never put anything metal near a live circuit.
  • Keep fingers off of hot surfaces.
  • Keep all loose objects away from the car.
  • Use extreme caution around water.
  • Always unplug your charger after use.

Where Is The 12 Volt Battery In A Tesla?

To gain access to the 12 volt battery, you’ll need some tools and gloves. Make sure you’ve got an extra set of hands available.

  • Then, open up the trunk and unlock the doors.
  • Once you’re inside, turn off the ignition and make sure your windows are rolled down. Finally, use the touchscreen to power off your vehicle.
  • Unclipping and raising the back seat reveals a compartment. There is a black cover under which is a rectangular clip. This is what you need to remove.
  • Once this is done, you can open the trunk and get to the battery.
  • There is a bolt right on the top that you’ll take out along with the two supports. The negative side comes off first (the black part) and then the positive (the red part). Once all is disconnected the battery goes in.
  • The car comes on with a whirring noise after putting the new battery in place, securing it with bolts and support bars, putting on the positive first (red) then the negative (black), and putting the vent cover back on.
  • Then you put the top cover back on – line it up before pushing it in as the clips will break easily – go back to your backseat and reconnect the high voltage plug and the cover, and then you push the seats back into place.

Can I Charge My 12 Volt Battery Using An Alternator?

No. The alternator only charges the battery when the engine isn’t running. When the engine starts, the alternator stops charging the battery.

Why Should I Use an Inverter?

An inverter allows you to run accessories like air conditioners, refrigerators, and lights without draining the battery.

Do Tesla Cars Have Battery Failure Warning Indicators?

They do have this feature. All Tesla vehicles have an indicator light on top of the dashboard that indicates whether the battery is healthy or whether the battery needs replacing. 

These indicators look somewhat similar to those on hybrid vehicles. If the light flashes red, it means that the battery is deteriorating quickly. If the battery is damaged and cannot be fixed, this could result in a fire. In this case, the car may stall out completely.

When Does My Warranty On My Tesla Battery Expire?

Your warranty begins when you take delivery of the car. However, your warranty expires after 6 years, regardless of how many miles you drive the vehicle. After that, you can purchase extended warranties up to 5 years.

Will a Jump Start Fix My Low Battery Problem?

This only works with certain types of batteries. A jump starter can fix a dead battery temporarily. But, we recommend that you replace the battery.

How Fast Can You Charge A 12 V Battery?

Most 12 volt batteries can be charged within 4 hours using a standard car charger.

What Should I Look For When Buying The Best 12 Volt Battery?

When buying a new 12 volt battery, look for one that has been manufactured by an authorized Tesla dealer. This means that the battery came from the factory ready to go directly into your vehicle. Additionally, look for a battery that was tested by Tesla before selling it to you.

Can You Charge A 12 Volt Battery With A Solar Panel?

Yes, you can use solar panels to recharge a 12 volt battery. As long as you don’t overload the battery, you can use a solar panel to recharge a 12 volt lead acid battery.

Battery Servicing

 A lot of times, this battery gets damaged and needs to be replaced. Sometimes, if the owner doesn’t want to swap out the battery, then he or she can get a new one at a local auto parts store.

Other times, if the owner wants to swap out the battery himself, he or she can call a local shop and have them do it for him or her.

A Tesla is a very expensive car. It needs regular maintenance to keep running properly. Service centers keep 12V batteries for Teslas in stock, and you can easily swap them out yourself.

However, you might be stranded without a battery if you live far away from a service center. Mobile service is available 24/7, but you’ll need to schedule an appointment ahead of time.

You should always use the official charger if possible. Driving a long distance to a service center is never fun. Having someone else tow your car to a service center is also not ideal.

However, if you’re stuck without a charger or a tow truck, there is another option. An overnight delivery may be the best bet. This option requires a bit of planning ahead of time, but it could save you a lot of money.


Hopefully this guide has helped you to learn about 12 Volt Tesla Batteries!

Michael Schuck

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