2024 Tesla Model Y Battery Size, Specs, and Replacement Guide

As an ASE-certified master technician, I frequently get questions about electric vehicle (EV) maintenance. A common source of confusion is the low-voltage battery system in modern EVs. If you are looking for the traditional 12V battery specs for a 2024 Tesla Model Y, you are in for a technological surprise. Starting in late 2021 and carrying through to the 2024 model year, Tesla completely ditched the traditional 12V lead-acid battery in favor of a proprietary 16-volt lithium-ion (Li-ion) low-voltage battery.

Because of this massive architectural change, standard battery metrics like Cold Cranking Amps (CCA) and BCI group sizes do not apply to the 2024 Model Y in the traditional sense. Here is everything you need to know about servicing and replacing the low-voltage battery in this generation.

Quick answer: 2024 Tesla Model Y Battery Specs

• BCI Group Size: N/A (Proprietary Tesla 16V Lithium-Ion form factor).
• Cold Cranking Amps (CCA): N/A (EVs do not "crank" an engine; this battery simply boots the computers and engages the high-voltage contactors).
• Reserve Capacity: ~6.9 Ah / 99 Wh (Lithium-ion rating, highly efficient).
• AGM vs Flooded Requirement: Neither. The 2024 Model Y strictly requires the OEM 16V Lithium-Ion battery.
• Terminal Layout: Proprietary quick-disconnect data and power harness, located under the hood near the HEPA filter/cowl area.
• Physical Dimensions: Considerably smaller and lighter than a standard automotive battery (roughly the size of a large motorcycle battery).
• Dual-Battery Setup: N/A.

Replacement battery options

Because the 16V lithium-ion architecture is entirely proprietary to Tesla, you will not find aftermarket replacements at your local auto parts store. Traditional brands like Interstate, Optima, DieHard, Odyssey, and ACDelco do not manufacture a 16V lithium-ion drop-in replacement for the Model Y.

• OEM Tesla 16V Li-ion Battery: You must purchase this directly from a Tesla Service Center or via the Tesla app. (Part numbers vary by specific build date, but commonly fall under Tesla PN 1129182-00-B or superseding numbers).

Do not attempt to retrofit a 12V AGM or flooded battery into a 2024 Model Y. The DC-DC converter is programmed to charge a 16V lithium system, and connecting a 12V battery will cause immediate catastrophic system faults.

AGM vs flooded — which does this vehicle need?

The 2024 Tesla Model Y needs neither. Older Model Y vehicles (2020 and early 2021) utilized a traditional 12V flooded/lead-acid battery (AtlasBX). However, lead-acid batteries degrade rapidly in EVs due to constant deep cycling, often failing every 1 to 2 years. Tesla engineered the 16V lithium-ion replacement to last the lifetime of the vehicle, completely eliminating the need for AGM or flooded lead-acid chemistry.

Post-installation relearn / reset procedure

If you are replacing the 16V battery (usually only necessary if the battery has suffered a physical fault or internal failure, as they are designed to last 10+ years), you must follow strict safety protocols:

1. Open the frunk and remove the plastic cowl/maintenance panel.
2. Navigate to Controls > Safety > Power Off on the center touchscreen.
3. CRITICAL: Disconnect the High Voltage (HV) First Responder Loop under the hood to isolate the high-voltage pack.
4. Disconnect the 16V battery harness.
5. Install the new 16V battery and reconnect the harness.
6. Reconnect the HV First Responder Loop.
7. The vehicle's computers will boot up automatically once the 16V and HV systems are re-engaged. The vehicle's Battery Management System (BMS) will automatically recognize the new module and perform its own internal self-checks. No external scan tool reset is required.

Signs of a failing battery

Even lithium-ion batteries can experience anomalies. Watch for these symptoms:

• Screen Warnings: The most obvious sign is a persistent alert on the main screen stating, "Electrical system backup power is reduced - Vehicle may consume more energy while idle." or "Schedule service to replace low voltage battery."
• Software Glitches: Slower than normal screen boot times, erratic window behavior, or failing to wake up from the Tesla app.
• Loss of Accessories: The 16V battery powers the lights, horn, windows, and computer displays. If the car is completely dead and unresponsive, the 16V system has failed or depleted.

Common battery issues for this generation

The switch to 16V lithium-ion has made the Model Y's low-voltage system incredibly reliable compared to previous generations. However, the most common issue owners face is jump-starting confusion.

Because the system runs at 16 volts, you cannot jump-start a standard 12V gas car using a 2024 Model Y. Attempting to do so will damage the Model Y's sensitive electronics. If your Model Y’s 16V battery dies, it must be jumped using an external 12V-16V portable jump pack applied to the specific jump posts hidden behind the front tow-eye cover to pop the frunk, followed by a proper charge sequence.

If you are dealing with EV battery warnings or are uncomfortable working around the High Voltage loop to service your 16V system, leave it to the professionals. Find a trusted shop on Repairius.