Battery to battery charger 12V to 12V with 20A for lead-acid, GEL, AGM and lithium batteries

The device is primarily designed for operation on the 13-pin trailer socket of the towing vehicle to charge the caravan battery. It automatically regulates itself so that the load capacity of the socket and the vehicle's electrical system connected to it (12 V / max. 20 amps) is not exceeded. From this perspective, the device's performance results. The charging converter is installed in the caravan/camper cabin and provides the optimal charging voltage for the battery, independent of vehicle electrical system voltage fluctuations and cable/connector voltage losses.

For this purpose, 4 adjustable IU1oU2 charging programs for classic lead-acid, gel, AGM, and modern lithium LiFePO4 leisure batteries are stored in the device. They enable unsupervised, rapid, and gentle full charging from any state of charge, followed by full maintenance.

In modern EURO 6, 6 + plus vehicles with energy-saving, intelligent alternators, their voltage fluctuates significantly depending on the driving condition (12.6 V ... 15.5 V). The charging converter now completely compensates for these fluctuations for uniform charging of the leisure battery and to protect the 12 V consumers connected to it.

Even with conventional alternators and long connecting cables, shorter charging times and fully charged batteries can now be achieved due to the higher charging currents possible.

Product advantages:

• High charging performance even on short journeys or full charge during longer journeys.
• Increases/decreases the voltage to the necessary level to precisely charge the leisure battery with its optimal charging curve.
• Completely compensates for line losses and voltage fluctuations of the alternator, such as those that constantly occur to a significant extent in Euro 6 vehicles (intelligent alternators).
• Compact design, low weight (high-frequency switch mode technology) and robustly dimensioned power components for safe operation.
• Significantly better energy balance of the leisure battery without interfering with the starter circuit
• Connected 12 V consumers are protected against overvoltage and voltage fluctuations.
• The charging voltage is free of peaks and regulated so that overcharging of the batteries is impossible.
• Fully automatic operation: The device is constantly connected to the batteries and is automatically activated by the running alternator of the vehicle. When the engine is off, the batteries are not discharged.
• Parallel and buffer operation: With simultaneous consumption, the battery continues to be charged or kept full. The device automatically calculates and monitors the adjustment of charging times.
• Unsupervised charging: Multiple protection against overload, overheating, overvoltage, short circuit, malfunction and battery reverse discharge through electronic regulation up to complete disconnection of the device and battery.
• Built-in vehicle electrical system filter: Trouble-free parallel operation with other charging sources (EBL, chargers, engine and fuel generators, solar systems) on one battery.
• Charging cable compensation: Voltage losses on the charging cables are automatically regulated.
• Connection for battery temperature sensor (included in delivery): For lead batteries (acid, gel, AGM), the charging voltage is automatically adapted to the battery temperature, resulting in better full charging of the weaker battery in cold weather, and unnecessary battery gassing is avoided in summer temperatures.
• LiFePO4 batteries: Battery protection at high and especially at low temperatures < 0°C.
• Charging aid for deeply discharged lead batteries: Gentle pre-charging of the (lead-acid, gel, AGM) battery up to 8 V, then powerful support of the battery even with consumers still switched on.
• Adjustable battery types: 4 charging programs for the different battery types are stored in the device, selectable via 2 slide switches on the device.
• GEL Batteries: 14.4V / 13.8 / 6-12h
• AGM-2 and Lead Crystal Batteries: 14.7V / 13.6 / 1.5-5h
• LiFePO4 Batteries: 14.4V / 13.8 / 0.3-1h / Charging current reduced to 2A below 0°C
• LiFePO4 Batteries (Heated): 14.4V / 13.8 / 0.3-1h / Full charging current below 0°C for batteries that are internally heated or suitable for charging below 0°C.

Further settings and functions:

Return charging branch for 12V starter battery

The device contains a charging branch that can provide support charging and charge maintenance for the 12 V STARTER battery during long periods of inactivity. It automatically activates when the LEISURE battery is sufficiently charged, e.g. by a mains charger (see Technical Data "Return charging branch"). A small portion of the charger current (approx. 0 - 1 A) is branched off from the LEISURE battery to the STARTER battery.
Charging voltage and current are reduced, so that overcharging of the STARTER battery is impossible.

2 operating modes for automatic ON / OFF control of the device are possible:

Connect terminal "D+" or terminal 15 (ignition): Activation of the charging converter by control signal "D+" or terminal 15 from the vehicle. Particularly recommended for EuroNorm 6 and 6+
For special applications, voltage-controlled from the increased starter battery voltage when the engine is running (not suitable for EURO 6 vehicles!)

Scope of delivery:

• B2B20Vo1212V battery-to-battery charger / charging booster, Votronic 3321
• Battery temperature sensor 825