What kind of battery does a 2018 Honda Accord take?

Most 2018 Honda Accord gas models (1.5T and 2.0T) use a BCI Group 51R 12‑volt lead‑acid battery, and many trims benefit from an AGM or EFB variant if equipped with idle‑stop; the 2018 Accord Hybrid uses a Group 51R AGM 12‑volt auxiliary battery. The key fob takes a CR2032 coin cell. Below are the details, options, and tips to ensure a correct and durable replacement.

The 12‑volt battery: size, type, and key specs

For starting, lighting, and accessories, the 2018 Accord uses a compact “Asian/JIS” fitment commonly specified as BCI Group 51R. This group size defines the battery’s physical dimensions and terminal layout (the “R” denotes reversed terminals compared with Group 51). Depending on trim and features, Honda may specify enhanced designs such as EFB or AGM to better tolerate frequent cycling from idle‑stop systems.

Here are the core specifications you should match when buying a replacement battery:

• Group size: BCI 51R (top‑post, reversed terminals)
• Chemistry/type: Lead‑acid; AGM or EFB recommended where idle‑stop is present; standard flooded is acceptable on non–idle‑stop trims
• Cold Cranking Amps (CCA): Typically 410–500 A (equal or higher than OEM is fine)
• Reserve Capacity (RC): As high as practical within the 51R form factor for better resilience
• Dimensions (approx.): 9.3 x 5.1 x 8.9 inches (L x W x H)

Matching the group size and terminal orientation ensures the battery fits the tray and cables, while choosing AGM/EFB improves durability if your Accord frequently cycles the engine at stops or endures hot/cold climates.

By engine and trim

Battery fitment is consistent across most 2018 Accord models, but type recommendations vary with powertrain and features like idle‑stop. Use the owner’s manual or a VIN-based parts lookup to confirm your exact spec.

• 1.5T and 2.0T (gasoline): Typically BCI Group 51R; standard flooded is common, but AGM/EFB is preferred for trims with idle‑stop for improved cycling life.
• Accord Hybrid: BCI Group 51R AGM 12‑volt auxiliary battery (powers vehicle systems; high‑voltage traction battery is separate). Location is commonly in the rear of the vehicle.

While the physical size is generally the same (51R), hybrids almost always specify AGM, and some non‑hybrid trims with idle‑stop also benefit from AGM/EFB for longevity.

Choosing a replacement: what matters most

Beyond size, a few practical considerations can help you pick a battery that lasts longer and performs better in your climate and driving pattern.

• Type: AGM or EFB for idle‑stop or short-trip driving; standard flooded is acceptable for steady highway use without idle‑stop.
• CCA and RC: Meet or exceed the OEM ratings; higher CCA helps in cold climates, higher RC supports accessories with the engine off.
• Warranty: Look for at least a 3‑year free replacement on AGM/EFB; pro‑rated terms vary.
• Venting and fit: Ensure proper venting (AGM often includes vent provisions) and that the case and terminals match 51R exactly.
• Brand/quality: Established brands and fresh stock (recent manufacture date) improve reliability.

Selecting a high‑quality 51R with appropriate technology for your driving conditions can significantly extend service life and reduce no‑start issues.

Replacement basics, relearns, and battery sensor reset

Swapping the battery on a 2018 Accord is straightforward, but a few steps help preserve settings and ensure stable idle and charging behavior afterward.

1. Preserve memory: Use a 12‑volt memory saver if available to retain radio presets and window auto‑up/down.
2. Safety first: Park, set the brake, wear eye protection. Remove the negative (–) cable first, then the positive (+).
3. Swap the battery: Remove the hold‑down, lift out the old battery, clean terminals/tray, install the new 51R, secure the hold‑down, connect positive (+) then negative (–).
4. Battery sensor: The negative cable includes a battery management sensor. After replacement, perform a battery sensor reset and idle relearn if available with a scan tool; many shops can do this quickly.
5. Idle relearn (if needed): With all accessories off, warm the engine fully, then let it idle undisturbed for about 5 minutes. Some procedures call for holding 3,000 rpm until the radiator fan comes on, then idling for several minutes.
6. Restore auto functions: Re‑initialize auto‑up/down windows and, if equipped, the moonroof by fully closing and holding the switch for a second.

These steps help the ECU and charging system “learn” the new battery and prevent rough idle or charging anomalies, especially on vehicles with idle‑stop.

Key fob battery

If you were asking about the remote, the 2018 Accord key fob uses a common coin cell that’s easy to replace at home.

1. Battery type: CR2032 3V coin cell.
2. Replacement: Remove the metal key, gently pry the fob case apart along the seam, swap in a fresh CR2032 (positive side facing the correct direction), snap the case closed, and test.

A fresh CR2032 quickly restores range and responsiveness; avoid touching the cell faces with bare fingers to keep contacts clean.

Summary

The 2018 Honda Accord typically uses a BCI Group 51R 12‑volt battery. Gas models commonly accept standard flooded or, preferably for idle‑stop trims, AGM/EFB; the Hybrid specifies a Group 51R AGM auxiliary battery. Match the 51R size and equal‑or‑higher CCA, consider AGM/EFB for durability, and perform a sensor reset/idle relearn after installation. The key fob uses a CR2032 coin cell. For exact specifications by VIN or trim, consult the owner’s manual or a dealer parts lookup.

How much does it cost to replace a battery in a Honda Accord 2018?

The average cost for a Honda Accord Battery Replacement is between $223 and $244. Labor costs are estimated between $45 and $66 while parts are typically priced around $178. This range does not include taxes and fees, and does not factor in your unique location. Related repairs may also be needed.

What group size is a Honda Accord battery?

The Honda Accord typically uses a Group 51R battery for 4-cylinder models and a Group 35 or 24F battery for V6 models, according to various sources. However, some sources mention that the 24F battery can be used as an upgrade for the 4-cylinder models as well. The 24F battery is larger and may require some adjustments for fitment, but it provides more power. 
Here’s a more detailed breakdown:

• 4-cylinder Accords: Typically use a Group 51R battery, according to multiple sources. 
• V6 Accords: Typically use a Group 35 or 24F battery, according to some sources. 
• Upgrade: The Group 24F battery can be used as an upgrade for 4-cylinder Accords, offering more power and potentially longer life, according to a YouTube video. 

When selecting a battery, it’s always a good idea to:

• Consult your owner’s manual: This will provide the specific battery size recommended for your year and engine type. 
• Check with a parts store: They can verify the correct battery size for your vehicle based on the year, make, and model. 
• Consider the climate: If you live in a very cold climate, you may want to consider a battery with a higher cold cranking amp (CCA) rating. 

Do Hondas need a special battery?

Types of Batteries for Honda Vehicles
Honda vehicles typically require either lead-acid or AGM (Absorbent Glass Mat) batteries.

What battery does a 2018 Honda Accord take?

The Honda Accord 2018 battery type depends on the engine, with the 1.5L engine typically using a Group Size H5 (or 47) AGM battery, and the 2.0L and Hybrid models using a Group Size H6 (or 48) AGM battery. You should confirm the exact battery group size by checking the sticker on your current battery or referring to your car’s owner’s manual.
 
Key Details

• 1.5L Engine: Generally uses a Group Size H5 (or 47) AGM battery. 
• 2.0L & Hybrid Engines: Typically use a Group Size H6 (or 48) AGM battery. 
• AGM vs. Standard: The 2018 Accord often comes with an Absorbed Glass Mat (AGM) battery for better performance, and you should not replace an AGM with a standard flooded battery. 

How to Confirm Your Battery Type

1. Check the sticker on your current battery: The group size (e.g., H5, H6) and type (AGM) should be listed on the label. 
2. Consult your owner’s manual: This will provide the exact specifications for your specific vehicle. 
3. Use an auto parts store locator tool: Websites like Firestone Complete Auto Care, Advance Auto Parts, or AutoZone.com have tools to help you find the correct battery for your year and engine.