Battery Remote Switches & Relays

Sale of Battery Remote Switches and Relays for Boat

This price catalog presents remote battery switches for yachts, as well as relays for boats from the world's best manufacturers of specialized electrical equipment for use in aggressive marine conditions.

If you find it difficult to choose battery remote switches and relays for your yacht, get free professional advice right now from experienced sailors - topRik marketplace experts. To do this, use the feedback form, call the specified phone number or send your questions to email address [email protected].

Working Principles of Battery Remote Switches & Relays

The electrical system of a sailing yacht runs on batteries most of the time. On a motor yacht, the engine runs longer, but during anchorages the onboard equipment is also powered by the battery. If the yacht does not have solar panels or a wind generator, then the batteries are regularly deeply discharged.

Incorrect or untimely charging of batteries leads to loss of capacity, reduces operating time without recharging and, ultimately, batteries fail prematurely. Replacing a high-capacity battery is an expensive procedure, which can be avoided with chargers specifically designed for yachts. There are two types of charging devices used on sailing and motor yachts. The first charges the batteries from the shore AC power supply, the second - from the internal combustion engine generator.

AC devices have a high power factor, operate over a wide input voltage range and are capable of charging all types of lead-acid and lithium batteries.

Models powered by a yacht engine generator have an input voltage of 12 V or 24 V and a charging current of up to 400 A. They are suitable for charging battery groups with a capacity of up to 900 Ah or more.

The devices are equipped with a battery temperature sensor, a sensor that compensates for voltage drop in a long cable, and a remote control.

To prevent short circuits and provide convenient battery management, relays and switches, both manual and remote, are used.

How Does a Remote Switch Work?

Circuit breakers are designed to disconnect the main positive or negative conductors from the battery in a DC electrical system. The devices allow you to isolate the battery remotely from anywhere in the vehicle, which reduces the likelihood of a fire in the event of a malfunction and creates additional convenience when operating electrical equipment under normal conditions.

On boats, 12 and 24-volt ground switches are used with both service and starting battery groups. Since the operating modes of these batteries are different, the requirements for remote power switches for them are also different. The circuit breaker for the service group is selected based on the maximum continuous current expected in the circuit. For the starting battery disconnector, the overload capacity is important, that is, the current that the switch can withstand for 30 seconds.

How Does a Battery Relay Work?

The battery decoupling relay automatically connects a second battery for charging from the generator or battery charger. The device is installed between the starting and additional batteries and is activated in one of two ways:

  • when it is supplied with control voltage from the ignition or generator;
  • when the voltage at the battery terminals exceeds the set value, usually 13.0-13.3 volts.

After the engine turns off, the battery voltage drops to 12.8 volts, the relay opens and disconnects the batteries.

If the cross-section of the cable connecting the relay to the battery is chosen correctly, then, regardless of the method of activating the relay, the voltage drop across it is 0.04-0.06 volts, which is significantly lower than that across a diode insulator. And since the length of this cable often does not exceed one meter, the cost of installing a relay is lower than a charging insulator of the same rating.

If one of the batteries connected to the relay is severely discharged, and the other, on the contrary, is fully charged, then, depending on the relative sizes of the batteries, when turned on for the first time, a high, short-term inrush current will occur, which will damage the relay. Therefore, to avoid dangerous overheating, the decoupling relays and cables must be designed to withstand this load.

Types and Choice of Battery Remote Switches & Relays

Choice of the type of remote switches for a particular boat depends on the layout of the boat's electrical system and the amount of equipment that needs power.

Battery disconnect switches with remote control are used on cars and boats in circuits with voltages from 12 V to 48 V and a maximum continuous load of up to 500 A (at 12 V).

Models are available to open one or two conductors at the same time; some devices are equipped with a lock or a removable key that prevents accidental activation.

A lock on the ground switch immobilizes the boat or vehicle and ensures its safety. With the switch locked, there is less chance of battery drain or theft. Switches with flange housing allow flush-mounted or surface-mounted installation.

Double-pole and Single-pole Battery Switches

Double-pole ground switches are used where it is necessary to open the positive and negative conductors and completely disconnect the electrical system from the voltage source. Another use case is to simultaneously turn off the 12 V and 24 V circuits on the car.

The maximum continuous load in each circuit of such switches is up to 350 A. The permissible current for 10 seconds is up to 1000 A.

Single-pole rotary switches disconnect the car or boat battery from the load. They are used to open a positive or negative conductor. The tinned copper studs in such devices have low resistance and provide maximum conductivity.

Both types of mechanical disconnect switches are available with fire protection and IP66 protection, so they can be installed in open areas and on vehicles carrying dangerous goods, such as fuel tankers. Remote switches for yachts have a high level of moisture resistance.

Combined Battery Switch

If two batteries are installed on a boat, truck or car, one of which is used to start the engine, and the second to power the equipment, then a four-position power switch is used.

This switch allows you to use the first or second batteries independently and, if necessary, combine them to start the engine. If the switch does not open the generator excitation circuit, then in order not to damage the diodes, turning it to the “off” position is only allowed when the engine is turned off.

Choosing a Relay for a Boat

Relays are a battery decoupling device. Such devices are designed to charge two or three batteries from a single charging source - a generator or a single-output AC charger. There are four types of devices that solve this problem.

  • Manual connection is the oldest method used, with a four-position rotary switch. The advantage is ease of installation. Disadvantage - it requires constant human supervision to connect and disconnect batteries. Operator errors will result in both batteries being discharged, not charging correctly, and possibly damaging the generator. If a high current flows through the switch for a long time, the springs in it heat up, the contact density drops, and a breakdown occurs, which can cause the plastic case to melt.
  • Diode isolators - a set of diodes mounted on the heatsink ensures current flows in one direction and ensures that high current does not flow towards a dead battery and cause a fire. This is the most common and safest method of decoupling batteries at the moment. However, its significant drawback is the voltage drop across the device of 0.8-1.2 volts. This voltage drop reduces the generator's ability to charge the batteries by 70% and requires the installation of an external generator voltage regulator to compensate for the voltage drop.
  • Battery separators based on MOSFET transistors are electronic devices whose voltage drop is 0.04-0.6 volts. Like diode insulators, they allow current to flow in only one direction. Separator decoupling circuits are used to connect one or two generators simultaneously and are designed for two to four battery outputs.
  • Battery decoupling relay - connects a second battery after the voltage on the battery connected to the charge source reaches a preset value, most often 13.3 volts.

Incorrect use of the relay or incorrectly selected relay rating to the power of the charge source or load installed in the circuit leads to failure of the relay and possibly a fire if the relay does not have a built-in current limit.