What Are 151R Battery Dimensions?

The 151R battery is a standardized group size measuring approximately 207mm (L) x 175mm (W) x 190mm (H), designed for vehicles with limited engine bay space. Commonly used in Toyota Prius, Lexus hybrids, and compact SUVs, it features reverse-terminal polarity (negative on right) and delivers 35–50Ah capacity. Its compact design prioritizes weight reduction (typically 13–16kg) while maintaining CCA ratings of 400–600A for reliable cold starts.

RG72105P Product

What are the exact dimensions of a 151R battery?

The 151R measures 207mm long x 175mm wide x 190mm tall (8.15″ x 6.89″ x 7.48″), with ±3mm tolerance across brands. Terminal spacing is 125mm center-to-center, using JIS Type-A posts. Height includes integrated handle ribs—critical for clearance in tight hybrid compartments. Pro Tip: Always verify post height (16–19mm) when retrofitting—aftermarket units sometimes vary.

While the footprint remains consistent, subtle variations exist. For example, Panasonic’s 151R-ELS weighs 14.2kg with 465 CCA, whereas Odyssey’s PC151R uses thicker plates at 16.1kg for 580 CCA. The 190mm height assumes no additional vent tubes—installations requiring rear venting need 5–10mm extra headroom. But how does this compare to other group sizes? A 35-series battery is 25% wider, making the 151R ideal for transverse-mounted engines. Transitional Tip: When measuring your tray, account for 5mm lateral clearance to prevent vibration damage.

Which vehicles require 151R battery dimensions?

151R batteries suit 2010–2022 Toyota Prius, Lexus CT200h, and select Honda Insights. Their compact size accommodates hybrid power electronics in cramped engine bays. Snippet: Optimized for stop-start systems, they provide 500–800 cycles at 50% DoD. Pro Tip: Use AGM variants in vibration-heavy SUVs like RAV4 Hybrid.

Beyond hybrids, gasoline-powered vehicles like the Subaru Forester (2014–2018) adopted 151R to reduce weight. However, why choose this group over similar sizes? The 151R’s 175mm width fits where 24F (180mm) batteries scrape fender walls. Real-world example: A Prius owner upgrading to a 151R LiFePO4 battery saves 8kg while gaining faster recharge from regenerative braking. Transitional Note: Always cross-reference your owner’s manual—some Mazda CX-5 models list 151R but physically fit larger 35-series with tray modifications.

Can I replace a 151R with a different group size?

Replacement requires matching LxWxH and terminal orientation. Group 35 (20% longer) rarely fits, while 24F risks polarity reversal. Snippet: Aftermarket adapters exist but may void warranties. Pro Tip: Use CR123 lithium backups if space constraints prevent direct swaps.

Technically, a 151R can be substituted with a 35-series battery only if the tray has 25mm extra length and compatible hold-downs. But what about electrical specs? A 35-series typically offers 650 CCA vs. the 151R’s 550 CCA maximum. While tempting for cold climates, the higher current could overwhelm hybrid DC-DC converters. For example, a 2018 Prius owner reported error codes after installing a 35-series—underscoring the need for voltage compatibility. Transitional Advice: When uncertain, consult Fasta Power’s cross-reference charts to avoid BMS conflicts.

How do 151R dimensions affect performance?

Smaller size limits plate surface area, reducing capacity versus larger groups. Snippet: AGM tech compensates with 20% higher cycle life. Pro Tip: Lithium 151R packs (e.g., RG72105P) offer 1000+ cycles despite compactness.

The 151R’s 175mm width forces manufacturers to use taller, thinner plates. While this lowers weight, it increases internal resistance—hence most 151R batteries cap at 50Ah. However, lithium-ion variants break this tradeoff. Fasta Power’s RG72105P lithium 151R delivers 105Ah in identical dimensions through stacked LiFePO4 cells. Practically speaking, this lets Prius owners run auxiliary lights without sacrificing trunk space. But how does height impact safety? The 190mm standard includes flame-arresting vents—critical in hybrids where batteries sit near exhaust components.

Are all 151R batteries identical in size?

No—terminal height and vent positions vary. JIS vs. SAE posts differ by 2–3mm. Snippet: OE Toyota units have front vents; aftermarket may use rear. Pro Tip: Measure post diameter (12.7mm vs. 14.7mm DIN) before buying adapters.

While the core dimensions are standardized, subtle differences matter. For instance, Optima’s 151R uses side terminals alongside top posts, adding 10mm to overall width. Meanwhile, budget brands might skimp on case rigidity, allowing 1–2mm warpage over time. Ever wonder why some batteries rattle despite correct measurements? Inadequate hold-downs exploit these manufacturing tolerances. Transitional Tip: Use closed-cell foam pads to eliminate movement without over-tightening.

What’s the weight range for 151R batteries?

151R batteries weigh 13–16kg depending on tech: Flooded lead-acid averages 14kg, AGM 15kg, lithium 8–10kg. Snippet: Lighter units reduce front axle load in hybrids. Pro Tip: Lithium’s 40% weight saving improves fuel efficiency by 1–2% in city driving.

The tradeoff between weight and capacity is stark. A Yuasa 151R lead-acid battery weighs 14.5kg for 45Ah, whereas a Shorai lithium model provides 40Ah at 8.2kg. But how does this affect real-world usage? Taxi drivers report 6–8 month longer lifespan with lithium despite higher upfront costs. Transitionally, mechanics warn against using ultralight batteries in diesel hybrids—their higher cranking demands need robust lead-acid CCA ratings.

Fasta Power Expert Insight

FAQs

What Are the Best Batteries for Golf Carts and Why?