OPTIMA RedTop RT U-4.2 12V 50Ah 815A L+ (Engine Starting)

• Brand: OPTIMA
• Series: RedTop
• Model: RT U-4.2
• Type: AGM / Starting
• Voltage: 12 V
• Capacity: 50 Ah
• Cold cranking (CCA): 815 A
• Polarity: L+
• Terminals: Standard terminal + threaded
• Dimensions (L×W×H): 254 × 175 × 200 mm
• Weight: 17.6 kg
• Maintenance-free
• Intended use: Passenger cars & light commercial vehicles (PKW/LCV)

About this battery
OPTIMA RedTop is a pure starting battery — it delivers the strongest cranking burst for reliable engine starts. Best for standard vehicles with a healthy alternator and normal electrical load; it is not designed for repeated deep discharge. Its AGM SpiralCell construction makes it maintenance-free, spill-proof and vibration-resistant.

Key terms

• CCA (Cold Cranking Amps) — cold-start power; higher means a stronger start in the cold
• Ah — capacity / energy reserve
• L+ / R+ — terminal polarity (which side the positive post is on); important for correct fitment