2019 Tesla Model S Battery Size & Group

Quick answer

• BCI Group Size: 51R
• CCA Rating: 360-400 CCA (approximate, consult your owner's manual for exact specifications)
• Reserve Capacity: 60-70 minutes (approximate)
• AGM vs. Flooded: AGM (Absorbed Glass Mat) is highly recommended, and often required, due to the vehicle's electrical demands and charging system characteristics.
• Terminal Layout: Top post, typically positive on the left, negative on the right (R-terminal layout for a 51R battery).
• Physical Dimensions (approximate): 9.38 inches (L) x 5.06 inches (W) x 8.81 inches (H).
• Dual-Battery Setup: Not applicable; the 2019 Tesla Model S uses a single 12V auxiliary battery.

Replacement battery options

Finding direct, readily available part numbers specifically marketed for the 2019 Tesla Model S can be challenging as Tesla often sources batteries through their service network. However, several premium AGM batteries in the 51R group size are excellent choices:

• Interstate: MT51R or MTX-51R (check for AGM versions)
• Optima: Optima YellowTop DH5
• DieHard: Platinum AGM 51R
• Odyssey: ODP-AGM51R (PC925L-A - verify fitment)
• ACDelco: 51RAGM (check for specific ACDelco AGM models)

Always verify the BCI group size, CCA, and physical dimensions before purchasing to ensure compatibility.

AGM vs. flooded — which does this vehicle need?

A 2019 Tesla Model S almost exclusively requires an Absorbed Glass Mat (AGM) battery for its 12V auxiliary system. While traditional flooded lead-acid batteries might physically fit, they are not designed to handle the unique electrical demands and charging profile of a Tesla. The Model S relies on its 12V battery for critical functions like powering various onboard computers, accessories, and initiating the high-voltage battery contactors. AGM batteries offer several advantages vital for this application:

• Deep Cycle and High Electrical Load Capability: Teslas place significant demands on their 12V battery, even when the car is