Battery-to-Battery Chargers for Boats

Battery-to-Battery Chargers

- Optimised battery charging without modifying the alternator -

What is a battery to battery charger? 

Also known internationally as B2B chargers, these devices are used wherever optimum battery charging is wanted without requiring intervention/manipulation of the alternator or complicated modifications to the on-board installation.

How is a battery to battery charger installed on board?

Installation is simple. Just connect the device between an existing battery and the battery you want to charge. Both PLUS cables should be fused close to the battery. Important: Both batteries must have a common MINUS connection. The unit becomes active as soon as a sufficiently high charging voltage is supplied to the device input. Depending on the version, B2Bs enable the charging voltage to be converted from 12 to 24 volts or vice versa. A battery for a 24 V bow thruster can easily be charged in the 12 V on-board power supply or a battery for 12 V navigation or radio equipment in the 24 V on-board power supply. With various characteristics for lead-acid, AGM, gel or LiFePO4 batteries, an additional battery of a different type can also be charged: For example, a LifePO4 battery can be charged in addition to a 12 V lead-acid starter battery.

Using an additional "thin" measuring line (1x 1.5 mm²) between the B2B and the battery to be charged, line and terminal losses can be detected and compensated for by the B2B, which is an ideal solution for charging bow thruster batteries that are often insufficiently charged due to long cable lengths.

Battery to battery chargers for service batteries

Battery to battery chargers are particularly useful for charging service batteries for use with low-emission Euro 6 engines. With these motors, the alternator is controlled by battery management systems (BMS), which prevent the alternator from charging the starter battery continuously and only up to a certain level. Normally, service batteries cannot be sufficiently charged with standard charging current distribution (isolating diode, etc.).