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Battery Model: YT S 4,2
Part Number: 8012-254
Nominal Voltage: 12 volts
NSN: 6140 01 457 5392
Description: High power, dual purpose engine start and deep cycle, sealed lead acid battery

Physical Characteristics:
Plate Design: High purity lead-tin alloy. Wound cell configuration utilizing proprietary SPIRALCELL® technology.
Electrolyte: Sulfuric acid, H2SO4
Case: Polypropylene
Color: Case: Light Gray
Cover:  OPTIMA Yellow
Group Size: BCI: 34

	Standard	Metric
Length: Width: Height: Weight:	10. 6.875 7.813 42.9 lb.	254 mm 175 mm 200 mm (height at the top of the terminals) 19.5 kg

Terminal Configuration: SAE / BCI automotive.

Performance Data:
Open Circuit Voltage (fully charged): 13.1 volts
Internal Resistance (fully charged): 0.0028 ohms
Capacity: 55 Ah (C/20)
Reserve Capacity: BCI: 120 minutes
(25 amp discharge, 80°F (26.7°C), to 10.5 volts cut-off)

Power:
CCA (EN -18°C): 765 amps
MCA (BCI 0°C): 870 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: YT S 4,2
These batteries are designed for starting and deep cycling applications and for use in vehicles with large accessory loads.

OPTIMA® YellowTop S 4,2

Recommended Charging Information:
Alternator: 13.65 to 15.0 volts
Battery Charger (Constant Voltage): 13.8 to 15.0 volts; 10 amps maximum; 6-12 hours approximate
Float Charge: 13.2 to 13.8 volts; 1 amp maximum (indefinite time at lower voltages)
Rapid Recharge: (Constant voltage charger) Maximum voltage 15.6 volts. No current limit as long as battery temperature remains below 50°C (125°F). Charge until current drops below 1 amp.
Cyclic or Series String Applications: 14.7 volts. No current limit as long as battery temperature remains below 50°C (125°F). When current falls below 1 amp, finish with 2 amp constant current for 1 hour.
All limits must be strictly adhered to.

Recharge Time: (example assuming 100% discharge  10.5 volts)

Current	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°F)

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.