2017–2023 Tesla Model 3 Battery Size (BCI Group and CCA)

Which Tesla Model 3 model years does this cover?

These battery specifications apply to every Tesla Model 3 built from 2017 through 2023 — the 1st generation (original, pre-Highland), compact ev sedan. Nothing in this specification changes between those model years. Pick your year for the engines it offered, what changed that year, and the problems recorded against it.

What changed during the 2017–2023 Tesla Model 3

• 2017US deliveries began July 2017, Long Range RWD only (310 mi), 18-in Aero or 19-in Sport wheels
• 2018Dual Motor Long Range AWD and Performance added mid-year; Mid Range RWD (264 mi) added in October
• 2019Standard Range and Standard Range Plus launch (Feb); Long Range RWD and Mid Range dropped during the year; Autopilot made standard
• 2021Major running refresh: heat pump replaces the PTC heater, chrome delete, powered trunk, new center console, double-pane front glass, 82 kWh pack on LR/Performance, ranges rise (SR+ 263 mi, LR 353 mi, Performance 315 mi)
• 2022SR+ renamed 'RWD' with a 272-mi LFP battery (charge to 100% weekly). Cars built after ~Dec 2021 switch the 12V lead-acid accessory battery for a 16V Li-ion unit
• 2023Final year of the original body; carryover, with the original-generation production ending late 2023 for the Highland changeover

What size battery does a 2017–2023 Tesla Model 3 take?

BCI group 85B24LS (JIS; 12V 45 Ah) through ~Nov 2021 production; 16V Li-ion after. Group size is a physical dimension and terminal-position standard, so a battery from a different group may not clamp down or may put the terminals on the wrong side.

Does the 2017–2023 Tesla Model 3 need an AGM battery?

The factory battery is a conventional flooded type. AGM is a valid upgrade, but never downgrade from AGM to flooded.

Where is the battery on a 2017–2023 Tesla Model 3?

Front compartment, behind the cabin-intake trim panel at the base of the windshield.

Does a 2017–2023 Tesla Model 3 need the battery registered after replacement?

This is the low-voltage accessory battery only, separate from the high-voltage pack. Cars manufactured before approximately December 2021 use a sealed 85B24LS 12V 45 Ah lead-acid battery (Tesla sells the OEM replacement for roughly $85–$130; typical life 3–4 years, and the car will warn on screen when it is failing. Replace promptly or the car can be bricked shut). Cars manufactured after approximately December 2021 (late-build MY2022–2023) instead have a Tesla 16V Li-ion low-voltage battery (15.5 V / 6.9 Ah, part 1598486-00-x) that Tesla says is designed to last the life of the vehicle. Check Controls > Software or the battery label to confirm which you have before buying parts. After replacing, run Learn New Battery from the service menu on supported firmware.