12 V 55 Ah AGM battery

This battery uses AGM (Absorbed Glass Mat) technology. The electrolyte is absorbed in glass fiber mats, making it fully sealed, maintenance-free, and free of gas emissions under normal use. It provides excellent cranking performance, low internal resistance, and extended service life thanks to the use of thicker plates.

The battery has external dimensions of 257 x 132 x 200 mm (Length x Width x Height, with handles). Its weight is 17 kg.

The battery must be installed in an upright position. It is recommended to leave at least 1 cm of space between batteries and to keep them away from heat sources.

For the 55Ah model, the recommended torque for the screw connections is 11 to 14.7 Nm (97 to 130 InLbs).

Only chargers with an IUoUo characteristic must be used to charge this battery.

Recommended voltage settings are: Float charge: 13.80 V at 25°CAbsorption charge: 14.25 V at 25°C (maximum 5 hours)Temperature compensation of charging is also recommended (–30 mV/°C or –17 mV/°F).

The maximum charging current is 30% of the nominal capacity C10, which corresponds to 15.3 A for this 55 Ah battery.

Before installation, ensure all loads and chargers are turned off. For optimal connection, it is recommended to mount the cable lug directly onto the battery terminal by first removing the pole adapter. Use reliable cable lugs and terminals of the appropriate size, tighten all connections firmly, and connect the negative cable last. Ensure correct polarity is observed.

Yes, it is possible to connect multiple batteries in series or parallel. However, all connected batteries must be of the same brand, type, capacity, and state of charge. Mixing old and new batteries is not recommended.

The nominal capacity of this battery is 55 Ah (C20).

The cold cranking amps (CCA) are 250 A according to DIN standard and 400 A according to SAE standard.

Yes, this battery is particularly suitable for systems requiring high currents, such as engine starting, thanks to its AGM technology which allows rapid discharge at high currents.

The battery is equipped with M6 / type A terminals. They are removable and compatible with all standard battery terminals, making it easy to integrate into various electrical configurations.

To optimize battery lifespan, avoid regular deep discharges beyond 50% of nominal capacity. Recharge the battery immediately after each discharge and ensure it is fully charged to 100% regularly, at least once per month. Keep the battery at a nominal operating temperature of 25°C, as a 10°C increase can halve its lifespan.

The allowed operating temperature range is –20 to 55°C. The recommended nominal operating temperature is 5 to 35°C, with an ideal temperature of 25°C.

No, this battery is designed to be maintenance-free thanks to its AGM technology. It is never necessary to add acid or distilled water. However, it is recommended to check the connections and the battery's general condition at least every three months, and to keep it clean and charged.

The battery must be recharged when its open-circuit voltage drops below 12.3 volts. Incomplete charges can damage the battery, so it is essential to fully charge it regularly, at least once a month.

To clean the battery, use only a soft, damp cloth. Never use additives, acids, or abrasive products on the battery.

Under normal use, AGM technology ensures the battery is fully sealed and does not release gas. However, in case of overcharging, lead-acid batteries can vent an explosive mixture of hydrogen gas. It is therefore crucial to ensure adequate ventilation if the battery is installed in an enclosed space and to respect the recommended charging voltages.

The Mastervolt AGM 12/55Ah battery comes with a two-year warranty.