OPTIMA® RedTop S 2,1 6volt


Battery Model: RT S 2,1
Part Number: 8010-355
Nominal Voltage: 6 volts
NSN: 6140 01 475 9414
Description: High power, sealed lead acid, engine starting battery

Warranty: 2 Year Manufacturers

Physical Characteristics:
Plate Design: High purity lead-tin alloy. Wound cell configuration utilizing proprietary SPIRALCELL® technology.
Electrolyte: Sulfuric acid, H2SO4
Case: Polypropylene
Color: Case: Dark Gray
Cover: OPTIMA Red

  Standard Metric
18.4 lb.
254 mm
83 mm
203 mm (height at the top of the terminals)
8.3 kg

Terminal Configuration: SAE / BCI automotive.

Performance Data:

Open Circuit Voltage (fully charged):     6.4 volts
Internal Resistance (fully charged):       0.0019 ohms
Capacity:                                           50 Ah (C/20)
Reserve Capacity:                               BCI: 110 minutes


CCA (EN -18°C):        815 amps
MCA (BCI 0°C):        1000 amps

Recommended Charging:

The following charging methods are recommended to ensure a long battery life:
(Always use a voltage regulated charger with voltage limits set as described below.)

Model: RT S 2,1
These batteries are designed for engine starting applications. They are not recommended or warranted for use in deep cycle applications. 

Recommended Charging Information:

Dynamo:                  6.65 to 7.5 volts; no amperage limit

Battery Charger:   6.9 to 7.5 volts; 10 amps maximum; 6-12 hours approximate

Float Charge:         6.6 to 6.9 volts; 1 amp maximum current (indefinite time at lower voltages)

Rapid Recharge:  Constant voltage charger) Maximum voltage 7.8 volts. No current limit as long as battery temperature remains below 50°C (125°F). Charge until current drops below 1 amp.

All limits must be strictly adhered to.

Recharge Time: (example assuming 100% discharge - 5.25 volts)


Approx. time to 90% charge


100 amps

50 amps

25 amps


35 minutes

75 minutes

140 minutes


Recharge time will vary according to temperature and charger characteristics. When using Constant Voltage chargers, amperage will taper down as the battery becomes recharged. When amperage drops below 1 amp, the battery will be close to a full state charge.

(All charge recommendations assume an average room temperature of 25°C, 77°C)

Always wear safety glasses when working with batteries.

Always use a voltage regulated battery charger with limits set to the above ratings. Overcharging can cause the safety valves to open and battery gases to escape, causing premature end of life. These gases are flammable! You cannot replace water in sealed batteries that have been overcharged. Any battery that becomes very hot while charging should be disconnected immediately.

Not fully charging a battery can result in poor performance and a reduction in capacity.

Shipping and Transportation Information:

OPTIMA batteries can be shipped by AIR. The battery is nonspillable and is tested according to ICAO Technical Instructions DOC. 9284-AN/905 to meet the requirements of Packing Instructions No. 806 and is classified as non-regulated by IATA Special Provision A-48 and A-67 for UN2800. Terminals must be protected from short circuit.

RT S 2.1 6V - 8010-355
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