What Does a 151R Battery Fit?

A 151R battery is a BCI Group-size 12‑volt starting battery that commonly fits many small Japanese cars—especially several Hondas such as the Honda Fit, CR‑Z, and some years/trims of the Insight and HR‑V. It shares the compact “51R-sized” footprint with reverse (right‑hand) positive terminal orientation, but you should always verify with your owner’s manual or a VIN-based fitment tool before buying.

What “151R” Means

The “151R” designation refers to a Battery Council International (BCI) group size with the “R” indicating reverse terminal orientation (positive post on the right when the posts face you). In practice, Group 151R batteries are compact, lightweight starting batteries designed for tight engine bays in small cars and certain hybrids’ 12V systems.

Key physical and performance traits

Understanding the typical size and layout helps confirm whether a 151R will fit your vehicle’s battery tray and cables.

• Form factor: Compact case comparable to Group 51R footprint
• Terminal orientation: Reverse (positive on right when posts face you)
• Typical dimensions: About 9.4 in (L) x 5.1 in (W) x 8.9 in (H), though small variations exist by brand
• Typical ratings: Roughly 350–500 CCA and 45–70 minutes reserve capacity (varies by model)
• Hold‑down style: Commonly top or bottom lip—match what your tray uses

Because dimensions and terminal layout are critical, confirm space, cable reach, and hold‑down compatibility on your specific vehicle before purchase.

Vehicles That Commonly Use a Group 151R Battery

While fitment can vary by year, trim, market, and whether the vehicle requires an AGM or flooded battery, the models below are among the most frequently associated with Group 151R. Always confirm with your owner’s manual, the label on your existing battery, or a VIN-based lookup.

• Honda Fit (many U.S. model years)
• Honda CR‑Z (2011–2016)
• Honda Insight (especially many 2010–2014 models)
• Honda HR‑V (select years/trims; verify per VIN)
• Other small import cars in the subcompact/compact class on a case‑by‑case basis

Because manufacturers can change battery trays or electrical specs mid‑generation, treat this list as a starting point, not a final authority.

151R vs. 51R: Are They Interchangeable?

Group 151R and 51R share a very similar footprint and the same reverse terminal orientation, which is why many owners notice cross-listings. In many vehicles, they physically interchange. However, there can be differences in case height, hold‑down lip geometry, and performance ratings across brands. Use the group size specified in your manual, and if you deviate, verify tray clearance, hold‑down fit, and minimum CCA requirements.

How to Confirm Fitment for Your Vehicle

To avoid a return or starting problems, verify the correct battery before you buy. These steps help ensure a proper match.

1. Check the owner’s manual for the specified BCI group (e.g., 151R or 51R) and whether AGM is required.
2. Read the label on your existing battery for group size, CCA, RC, and terminal orientation.
3. Measure the tray and compare hold‑down style and height clearance.
4. Confirm cable reach with the positive post on the correct side (reverse/right‑hand for 151R).
5. Use a VIN-based lookup from a reputable parts retailer for an additional cross-check.
6. If the vehicle has start‑stop or sensitive charging strategies, match chemistry (AGM/EFB) and specs.

When in doubt, matching the original equipment specifications is the safest route to ensure reliable starting and proper charging system performance.

Specs at a Glance

Here are the common characteristics you’ll see when shopping for a 151R battery.

• Nominal voltage: 12 V
• BCI group: 151R (reverse terminal layout)
• Approximate size: ~9.4 x 5.1 x 8.9 inches (L x W x H)
• Typical CCA range: ~350–500 (varies by brand/model)
• Chemistry options: Flooded lead‑acid or AGM (match vehicle requirements)

Exact numbers vary between manufacturers; always compare the label to your vehicle’s minimum requirements.

Summary

A 151R battery is a compact, reverse‑terminal 12V starting battery commonly fitted to small Japanese cars—especially many Honda Fit, CR‑Z, and some Insight and HR‑V models. It shares a footprint with 51R and can sometimes interchange, but you should verify group size, chemistry, dimensions, hold‑down, and CCA against your owner’s manual or a VIN‑based guide before purchasing.

What does 51 R mean on a battery?

The “51R” designation refers to the battery’s size and terminal orientation, with the “R” indicating that the positive terminal is on the right side when the battery is viewed from the front.

What does the R mean on a battery?

And the fourth shows the polarity of the battery based on the position of the negative pole. The R attribute indicates the position of the negative pole on the right side, while the L attribute indicates the position of the negative pole on the left side.

Are all 51R batteries the same size?

Group 51 and 51R batteries have nearly the same dimensions, typically measuring around 9.3 x 5.1 x 8.7 inches.

What cars use a 151R battery?

Delivering 340 Cold Cranking Amps (CCA), it ensures reliable starts for vehicles like Honda Civic, Insight, and Fit, even in tough conditions. The Group Size 151R features a maintenance-free design and durable construction, making it perfect for daily commutes and long trips.