Skip to content

Optima Red Top Starter Battery - 8003-251 12V 50Ah - RTR4.2, 2 Years Warranty

Original price £194.69 - Original price £194.69
Original price
£194.69
£194.69 - £194.69
Current price £194.69
  • Product Description
  • Technical Specification
  • Warranty Details
  • Product Number: RTR4.2

    High-performance starter batteries must deliver reliable cranking power across a wide range of temperatures and operating conditions, particularly in tuned, modified, and demanding street applications. The Optima Red Top 8003-251 is an absorbed glass mat starter battery engineered specifically to meet these requirements, providing strong, consistent starting performance where conventional flooded batteries may fall short. Optima's proprietary Spiral Cell AGM technology arranges pure lead plates in a tightly wound cylindrical cell configuration. This construction eliminates free electrolyte, delivers low internal resistance, and produces a high, stable discharge rate - resulting in the 815A cold cranking amp rating that underpins the battery's starting capability across temperature extremes." The 8003-251 operates at 12V with a 50Ah capacity (C20 rating) and measures 254mm x- 175mm - 200mm including terminal height. It weighs 18kg and is fitted with SAE post terminals in a standard positive-left (polarity 0) arrangement. Hold-down type is B00. This unit is compatible with start-stop technology - verify suitability against the vehicle label before fitment. No direct cross-reference data is provided; confirm compatibility prior to ordering. No additional variants of this SKU are currently listed. This battery is supplied with a 2-year manufacturer's warranty against defects in materials and workmanship. " . The OPTIMA REDTOP high-performance AGM Battery is designed for starter applications. Its ideal for tuned and street cars, and other high-performance applications. Its even powerful enough to start generators while having small space requirements. Key Feature: Backed by 2-year warranty for reliable use and dependable performance. Product Group: 3100, OPTIMA RED TOP BATTERY, Optima AGM Battery, purpose-built for dependable performance in the intended application. Engineered as a AGM Battery, delivering consistent, reliable operation in daily use. Manufactured by Optima, a trusted name known for dependable quality. Weighs 18.0kg, balancing power and manageability for easier installation and handling. . OEM-style fitment supports straightforward replacement and proper mounting. 12V system compatibility with standard vehicle electrical requirements. Compatibility: Engineered for modern passenger vehicles, providing reliable starting power, voltage stability, and long-term durability to support daily commuting and standard automotive electrical demands. Uses: Restores dependable starting for vehicles that need consistent, everyday performance. Suited to AGM battery applications, delivering steady operation in daily driving conditions. Supports stable power delivery for ignition, lighting, and onboard electronics. Performs reliably across short trips and longer runs where dependable restarts are essential. About MachineRefurb: MachineRefurb is an e-commerce platform specialising in replacement parts, spares and consumables for construction, agriculture and industrial machinery, serving customers across Ireland, the United Kingdom and Europe. We offer an extensive catalogue of over 200,000 products to keep your machines running. Standard delivery: 1-7 working days across Ireland, the UK and Europe. Fitment Warning: You must check your current battery against the specifications of this battery before ordering to ensure that this is the correct battery for your vehicle. Check battery technology, dimensions, terminal type, polarity, capacity (AH) and cranking performance (CCA). We cannot guarantee correct fitment under any circumstances.

    • Brand: Optima Batteries
    • Voltage: 12V
    • Capacity AH (C20): 50Ah
    • Cold Cranking Amps (EN): 815A
    • L x- W x- H: 254mm x- 175mm x- 200mm
    • Warranty period: 2 Years
    • Weight (Kg): 18
    • Capacity AH (C5):
    • Capacity AH (C10):
    • Capacity AH (C100):
    • Marine Cranking Amps (MCA):
    • Watt-Hours (WH):
    • Length (mm): 254
    • Width (mm): 175
    • Height Inc. Terminal (mm): 200
    • Terminal Placement: 0
    • Terminal Type: 1
    • Hold Down: B00
    • Case Size:
    • ETN Number:
    • TTNR:
  • New Grade - 24 Months Warranty from purchase is available on this product.
Frequently Asked Questions

Q1- What is the cold cranking amp (CCA) rating of the Optima Red Top RTR4.2?
ANS- The Optima Red Top 8003-251 is rated at 815A CCA measured to the EN standard, making it well suited to high-performance and modified engine applications that demand strong, reliable starting power.

Q2- What are the dimensions of the Optima Red Top 8003-251 battery?
ANS- The battery measures 254mm in length, 175mm in width, and 200mm in height including the terminal. Please verify these dimensions against your vehicle's battery tray before ordering.

Q3- What terminal type and polarity does the RTR4.2 use?
ANS- The RTR4.2 uses SAE post terminals with a standard positive-left polarity arrangement (polarity code 0, terminal type 1). Confirm your vehicle's terminal layout matches before fitment.

Q4- Is the Optima Red Top RTR4.2 compatible with start-stop vehicles?
ANS- The AGM technology used in this battery supports start-stop functionality in principle; however, suitability depends on the specific vehicle. You must verify compatibility against the vehicle's battery specification label before fitting this unit.

Q5- What hold-down type does the RTR4.2 require?
ANS- This battery uses hold-down type B00. Ensure your vehicle's battery mounting system is compatible with this hold-down configuration prior to installation.

Q6- What is the capacity of the Optima Red Top 8003-251?
ANS- The battery has a rated capacity of 50Ah measured at the C20 discharge rate. This figure reflects the total charge the battery can deliver over a 20-hour period under standard test conditions.

Q7- What technology does the Optima Red Top use and why does it matter?
ANS- The Red Top uses Optima's SpiralCell absorbed glass mat (AGM) construction, in which pure lead plates are wound in a tight spiral. This eliminates free liquid electrolyte, reduces internal resistance, and enables the high cranking output required for tuned and performance applications.

Q8- Does the Optima Red Top RTR4.2 have an IP rating for water or dust resistance?
ANS- No formal IP rating is published for this product. The AGM construction means there is no free electrolyte, which offers inherent resistance to vibration and spillage, but installation in fully exposed or submerged environments is not specified by the manufacturer.

Q9- What warranty is provided with the Optima Red Top RTR4.2?
ANS- The battery is covered by a 2-year manufacturer's warranty against defects in materials and workmanship from the date of purchase. Retain proof of purchase for any warranty claim.

Q10- How will the Optima Red Top RTR4.2 be delivered and what is the returns policy?
ANS- You may cancel your purchase within 14 days of delivery without providing a reason. To be eligible for a return, the item must be unused, in its original packaging and in a resellable condition. Proof of purchase is required.
Please note returns are not accepted for personalised or customised items, sealed goods that have been unsealed, or items that cannot be returned for hygiene reasons.
To arrange a return, contact us at customer@machinerefurb.com with your order number, reason for return and photos if applicable. Return postage is the customer's responsibility unless the item is defective, damaged or incorrect.

Q11- What are the delivery times?
ANS- Estimated delivery times are as follows:
* Ireland: 1-3 business days
* UK Mainland: 1-3 business days
* Northern Ireland: 3-7 business days
* European Union: 3-7 business days
All orders are shipped with tracking. You will receive tracking details by email once dispatched.

Q12- What is the warranty period for this product?
ANS- This product is covered under a 2-year warranty from the date of purchase.

Grade: New

Compare products

{"one"=>"Select 2 or 3 items to compare", "other"=>"{{ count }} of 3 items selected"}

Select first item to compare

Select second item to compare

Select third item to compare

Compare