What battery is in the 2018 Honda Accord Sport?

The 2018 Honda Accord Sport uses a 12‑volt BCI Group 51R starting battery under the hood, and its smart key fob uses a 3‑volt CR2032 coin-cell battery. In most trims and engines for the Sport model year, Honda fitted a Group 51R battery from the factory; owners sometimes upgrade to a physically larger unit, but 51R is the stock specification.

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

Honda equips the 2018 Accord Sport (both 1.5T and 2.0T variants) with a BCI Group 51R lead‑acid battery as standard. This is the familiar compact Honda/Toyota size with the reversed (R) terminal layout, and it fits the factory tray and hold‑down without modifications. Many cars came with a conventional flooded battery; some higher-demand trims and cold-climate replacements may use an EFB or AGM in the same group size.

Here are the key specifications you can expect for a Group 51R that meets or exceeds OEM performance:

• BCI group size: 51R (reversed terminals)
• Nominal voltage: 12 V
• Cold cranking amps (CCA): typically 410–500 A (higher is better for cold climates)
• Reserve capacity: roughly 70–85 minutes
• Dimensions (approx.): 9.3 in L × 5.1 in W × 8.9 in H (236 × 130 × 227 mm)
• Chemistry: Flooded lead‑acid (OEM), with EFB or AGM accepted as upgrades in the same size
• Terminal orientation: Positive on the right (when posts face you)

These specifications ensure proper fit and electrical performance with the Accord’s charging system and accessories. Choosing a higher CCA and quality construction (EFB/AGM) can improve durability, especially in extreme temperatures or with frequent short trips.

Variations, upgrades, and what to know

While Group 51R is the factory size, some owners opt to retrofit a larger Group 24F battery for additional reserve and cranking capacity. That requires a tray/hold‑down change and is not a direct drop‑in. If your Accord Sport has auto idle‑stop (common on many automatic/CVT models), an EFB or AGM in the 51R size is a smart choice for better cycle life. Manual‑transmission cars without idle‑stop typically do fine with a quality flooded 51R.

Consider these points when selecting a replacement:

• Climate: Choose higher CCA for cold regions; heat favors AGM/EFB for longevity.
• Driving pattern: Frequent short trips or heavy accessory use benefit from AGM/EFB.
• Warranty/support: Look for strong warranty terms and fresh manufacturing dates.

Matching your battery to your climate and driving habits will maximize reliability and lifespan, regardless of brand.

The key fob battery (remote)

The 2018 Accord Sport smart key fob uses a single CR2032 3V lithium coin cell. Replacements are widely available from major brands (Panasonic, Sony, Energizer, Duracell).

To replace the fob battery safely, follow these steps:

1. Slide out the mechanical key using the release switch.
2. Insert the key tip in the seam and gently twist to split the fob case.
3. Note battery orientation (positive “+” side typically faces up).
4. Swap in a new CR2032, avoiding contact with the flat faces to keep oils off.
5. Snap the case back together and reinsert the mechanical key.

After replacement, test lock/unlock and proximity start. If range is poor, re-open the fob and confirm the battery is fully seated with correct polarity.

How to verify what your car has

To confirm your exact battery specification, check the label on your current battery for “51R” and CCA, consult the owner’s manual (12‑volt battery section), or ask a dealer/parts retailer to look up your VIN. If a previous owner upgraded to a different group size (like 24F), the tray and hold‑down will usually look non‑factory or use adapters.

Summary

The 2018 Honda Accord Sport uses a 12‑volt BCI Group 51R battery from the factory, typically a flooded lead‑acid unit, with EFB/AGM upgrades available in the same size; the smart key fob takes a CR2032 coin cell. Verify on the battery label or in the owner’s manual, and choose higher CCA or AGM/EFB if you drive in extreme climates or want longer service life.

What type of battery does a Honda Accord have?

The Honda Accord typically uses either a Group Size 51R, 35, or 24F battery, depending on the model year and engine. Some newer models, like the 2018 Accord Hybrid, may use an H6 or H5 battery. 
Here’s a more detailed breakdown:

• 4-Cylinder Models: Often use a Group Size 51R battery. 
• V6 Models: May use a Group Size 35 battery. 
• 2018+ Models: Some may use an H6 or H5 battery. 
• Hybrid Models: May use an OPTIMA H6 YELLOWTOP or similar. 
• General Recommendation: A Group Size 24F battery can be used as a larger, more readily available alternative in some cases. 
• AGM Batteries: Many Honda Accords can also use AGM (Absorbent Glass Mat) batteries, which are a type of lead-acid battery. 

When choosing a replacement battery, it’s best to:

1. Check your owner’s manual: This will have the specific battery group size and type for your Accord model. 
2. Consult a parts professional: They can help you determine the correct battery for your specific Accord. 
3. Consider an upgrade: You can sometimes upgrade to a larger battery for increased power, but ensure it fits the battery tray and hold-down bracket. 

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 is the voltage of the battery in a Honda Accord 2018?

A properly functioning battery should produce about 12.4 to 12.7 volts of power.

What kind of 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.