Rafgeymir MVG gel 12 V 55 Ah

The MVG gel 12V/55Ah battery from Mastervolt is a high-performance, sealed service battery. Its main features include:

A voltage of 12V and a capacity of 55Ah.Strictly maintenance-free Gel technology.No gas release during normal use.Excellent resistance to intensive charge and discharge cycles.

This Mastervolt battery weighs 19 kg. Its overall dimensions, including terminals and transport handles, are 261 x 136 x 230 mm (Length x Width x Height).

No, never open the battery or add acid or distilled water. Thanks to its technology where the electrolyte is fully absorbed in gel form, it is maintenance-free. The pressure valves are sealed and opening them would destroy the battery.

It is recommended to install it in a vertical position (upright). However, a horizontal installation is also possible, provided it is not mounted on its shortest side. Its sealed design prevents any electrolyte leakage.

Under normal use, Gel technology produces no gas emissions. You can therefore install this battery in confined onboard spaces without requiring rigorous ventilation, unlike classic lead-acid batteries.

You must use a battery charger with an IUoUo charging profile. It is also highly recommended to use a charger equipped with a temperature compensation probe (-30mV/°C) to optimize the lifespan of your battery bank.

At a reference ambient temperature of 25°C, your charger voltage settings should be as follows:

Absorption voltage: 14.25 V (for a maximum of 5 hours). Float voltage: 13.80 V.

The battery accepts a maximum charging current of 27.5 A, which corresponds to 50% of its nominal capacity of 55Ah. This allows for exceptionally fast recharging compared to standard marine market practices.

To preserve its lifespan, avoid regular discharges exceeding 60 % of its nominal capacity. It is also essential to fully recharge the battery completely and immediately after each discharge cycle.

Although it is primarily optimized to serve as a house battery (powering onboard equipment), it delivers a cold cranking amperage (CCA) of 380 A (SAE standard) or 230 A (DIN standard). It can therefore occasionally assist with engine starting, but this is not its primary function.

Yes, you can connect them in series or parallel to increase the voltage or overall capacity of your battery bank. However, all batteries connected together must be of the same brand, type, capacity, and have the same initial charge level. Never mix new batteries with old ones.

When installing multiple units side by side, it is essential to maintain at least 1 cm of space between each battery to allow adequate heat dissipation and prevent overheating.

The permitted operating temperature range is between -20°C and 45°C. However, the recommended nominal temperature is 20°C. Note that every 10°C increase above this reference temperature halves the battery's lifespan.

The battery is maintenance-free internally. Simply check the connections every three months to ensure they are tight and free of corrosion. Keep the battery housing clean and dry using only a soft, damp cloth—no chemicals or abrasives.

Yes, due to its extremely low self-discharge rate, it maintains excellent charge during prolonged wintering periods. It is still recommended to store it fully charged and check its voltage periodically (recharge if it drops below 12.3 V).

The battery is equipped with standard type A terminals. During installation, it is recommended to use properly sized cable lugs, tighten connections firmly, and add insulating caps to prevent accidental short circuits.

No. It is strongly recommended to keep the battery away from any heat source, including the engine block. High ambient temperature accelerates self-discharge and significantly reduces overall battery life.

If the voltage of one battery differs by more than +0.49 V or -0.24 V from the average float voltage, or if the surface temperature difference between batteries exceeds 5°C, there is a malfunction. It is recommended to have a qualified technician inspect your installation.

Yes, for obvious electrical safety reasons, all loads (equipment) and chargers must be turned off during handling, installation, and connection of battery terminals.

Repeated incomplete recharges can irreversibly damage the battery. It is imperative to fully recharge it regularly to 100% of its capacity, ideally at least once a week during cyclic use.