Teslas have two types of onboard “batteries”: storage devices for chemical energy.
- A low voltage battery like cars have had forever, to manage everything besides the big electrical drivetrain components. This battery ranges from 12-48 volts, depending on the Tesla model and its equipment, and weights between 10-30 pounds.
- A high voltage battery that essentially replaces the gas tank, powering all propulsion between recharges. This battery ranges from 600-1000 volts and 1200-1700 pounds.
This article covers costs to replace #1, the low voltage battery.
For information about the cost of replacing a Tesla high voltage battery, click here.
Low voltage: Why?
Many Tesla owners are surprised to discover that their cars have a standard(ish) low voltage battery. Why does a car with a fancy, gigantic, high voltage battery also need a boring 20th-century tender?
It’s true that all cars with high voltage (HV) batteries use those high voltage batteries to support low voltage systems through a DC/DC converter. That is, the low voltage system is still powered by the great big battery.
But all of these cars also have a low voltage system to run all the things for which low voltage is more practical (headlights, door locks, wiper motors, you name it).
The low voltage battery, the chemical energy storage device, is there to smooth out the charging and discharging for low voltage across all the various current demands and operating conditions. It’s an energy reservoir to smooth out the spikes.
Also, in the case the HV battery is disconnected, the low voltage battery can still supply power to necessary systems and then reconnect the HV battery as appropriate.
Low Voltage: A more common problem
As of 2025, Tesla has sold over seven million vehicles. Very few of them have needed to replace their HV battery.They’re too new.
But every Tesla owner should expect to replace their low voltage battery within 3-5 years of the vehicle’s birthday (but some do last longer). It’s a normal wear item like tires and brake pads (just like other cars), and it should be inspected on a regular basis to avoid getting stranded when it finally fails.
Failure patterns are still being collected on Lithium Ion (Li-Ion) low voltage batteries, which are fairly new compared to the standard lead acid (PbA) batteries that have been around forever.
At Earthling we regularly encounter Tesla’s with low voltage lead acid (PbA) batteries that need to be replaced, and we stock parts to be able to perform most repairs in house the same day.
Sometimes the low voltage battery will trigger an alert and you can reach the service center before things escalate. Sometimes the alert will set once the condition has reached much higher severity, giving you a short time to pull over before the vehicle powers down. Sometimes there is no alert at all, and the car can simply not be started.
Example alerts are:
3 and Y: VCFRONT_a182_replaceLVBattery
S and X: GTW_w174_Replace12VBattery
A degraded LV battery may be the issue when:
- The battery repeatedly does not hold charge while in discharge mode (indicated by SX: GTW_w156, 3Y: VCFRONT_a219).
- The battery repeatedly accepts too much charge while charging, without reaching a low current cutoff (indicated by SX: GTW_w158, 3Y: GTW_a213).
- A resistance estimation test reveals low battery power (indicated by SX: GTW_w173, 3Y: VCFRONT_a404).
Cost of low voltage battery replacement:
The type of low voltage battery and the cost of replacement will vary depending on your model of Tesla and how it is equipped. For later model vehicles with options for low voltage battery chemistries (lead acid or lithium ion) you can look up which one your vehicle has by navigating through your center display:
On a Tesla’s touchscreen, in Software menu, click on the “Additional Vehicle Information” link in blue, and the car will display various build options that the car is equipped with.
As of May 2025:
Most lead acid batteries range between $100-250, cost of parts. Deep cycle styles are purchased through Tesla. Standard 12v batteries are available in the aftermarket.
Lithium Ion batteries are sourced from Tesla only and currently cost $350.
Cost to install ranges from $100-200.
Have alerts? Let us pinpoint the problem and provide you with an informed estimate for repairs. 100% Tesla factory service information and Toolbox scan tool.
If the internet could have fixed cars by now, repair shops would be out of business! Partner with Earthling Automotive to get your Tesla back on the road at the minimum cost: only what you need, ASAP. Call or text 415-875-9030, or book online today.
