A useful “craft” for a car is a do-it-yourself battery disconnect switch. Features of connecting and using the battery disconnect switch Remote battery disconnect switch

Simple scheme ground switch for a car.

Many motorists, when parking their car for a long time, want to disconnect the battery from the on-board network, and in order not to constantly remove the terminals, they independently install all kinds of mechanical switches in the engine compartment, because in serial passenger cars There are no such switches.

The contacts of mechanical switches must be designed to carry a current of several hundred amperes and have a very low transition resistance, so the use of conventional network switches or toggle switches in this situation is not acceptable. For these purposes, there are special car mass switches, for example, VK-318, or in some articles found on websites, the RAD-1 remote mass switch device is mentioned, although we were unable to find information on the RAD on the Internet. (Maybe, of course, we were looking in the wrong place, but still...).

The circuit that we want to propose does not have mechanical contacts, and its main advantage is that this mass switch can be controlled remotely using a small toggle switch or a button with fixed positions, installed in any place convenient for you. It can be installed inside the car, and in order to turn off the mass it is not necessary to open the hood lid.

This diagram was once published a long time ago in one of the radio engineering magazines, so we will not reinvent the wheel and redraw it in our own way, it is quite informative and intelligible, so we are posting a scan for you schematic diagram in the original as is without changes.

The figure shows that a powerful thyristor and diode are installed on an aluminum corner with dimensions indicated. On the vertical side (as shown in the picture) there is a hole through which it is attached in the engine compartment to the car body, not very far from the battery.

The thyristor works like a key; when the toggle switch is turned on, it will be open. But there is one “but”... As you know, a thyristor can pass current only in one direction (from the anode to the cathode), and in order for the battery to receive recharging from the generator while driving, a diode with the opposite polarity is installed in parallel with the thyristor.

Attaching the angle to the car body must have good electrical contact, and the wire connecting the thyristor to the tip must have a fairly impressive cross-section; you can use the one that connects the negative terminal of the battery to the car body; otherwise, there are no critical requirements. Some craftsmen advise placing the device in a metal box and painting it in the color of the car body.

The parameters of some powerful thyristors are shown in the following image, to enlarge which click on the picture.

In an attempt to protect their “iron horse” from talented and resourceful car thieves, car owners resort to all sorts of tricks and inventions. Some people install expensive alarms on their cars with a satellite tracking function, others tightly block steering wheel with a gear shift knob or a clutch pedal, while others install a simple sound “beeper”. There are even stories of bear traps being set at night. However, some car enthusiasts, in the old fashioned way, prefer to de-energize their “swallow” through a power switch, which can be hidden anywhere in the car and thereby seriously complicate the task of a potential thief.

Disadvantages of alarms

Of course, comparing such high-tech systems and a mass switch is like comparing Tetris and an iPhone, but even the simplest but time-tested things sometimes serve much more effectively than their modern counterparts.

What it is

Let's figure out what this device is. Any electrical circuit is a closed system. If the system is open, then no electric current flows and the electrical appliance does not work. An electrical device can be a light bulb, an electric motor, an integrated circuit, or a combination of them. The user just needs to press a button, press a key or flip a toggle switch - the circuit is closed - the light comes on, for example, the vacuum cleaner turns on, the TV starts working. Moreover, the wire through which voltage is supplied to the device is called a phase, and the second wire that completes the circuit is called “zero”.

Sometimes, in order to close the circuit and protect, for example, some machine, the neutral wire is diverted into the ground, then it is called “ground”. You can ground the equipment through something made of steel that has direct contact with the ground, for example, through water pipes. A large surface area sharply increases the conductor's flow area, reducing its voltage and making it safe for humans to touch. The tapping of zero over a large surface area is called mass. A ground switch is a device for breaking a circuit by opening the neutral wire.

In the car

A similar power supply system, only of a different voltage and amperage, exists in every car. Without paying attention to the details, we can distinguish two main elements of the automotive electrical circuit. The battery is a source of electricity, and the generator is a device that removes part of the thermal energy from fuel combustion to replenish the battery. The phase is given by the positive terminal of the battery, the ground is given by its negative terminal.

The car's ground switch is mounted to open the zero circuit, that is, that side of it that is not under load. This is done in order to prevent sudden voltage surges during the circuit closure, which could cause short circuit, failure of the vehicle's electrical and electronic equipment, and sometimes even to prevent a fire.

Installing the mains switch

It is quite simple and does not require serious intervention in the electrical circuit. However, it is still better to entrust installation to a qualified specialist. A modern mass switch can be mechanical (screwing in a locking screw) and electronic (pressing a button or a sequence of them).

They can also be divided by type of installation: open type and hidden installation. By activation method: manual (tactile pressure) and remote (activation from the key fob). IN last years The electronic mass switch, activated by sequentially pressing various buttons on the dashboard, has gained particular popularity. The user is told a combination of keys (usually in a completely random sequence) that he must press before turning on the ignition. Otherwise, the engine will not start because the mains switch will be open. The diagram of the simplest circuit breaker is shown below.

It should also be remembered that after a circuit break, failures in the electronic settings of various vehicle systems are possible. And in the latest cars premium class, even a short-term power outage to the on-board network is unacceptable and is considered a gross violation of operating conditions.

You will learn the necessary minimum information about the battery disconnect switch right now. Every yacht, boat or boat receives electricity using battery and often not alone. To switch between them, use a special device. The switch makes it easy to select a power source. If necessary, you can also select a combined (shared) mode of using batteries.

You may also need toggle switches, relays and switches that will help protect your boat's electronics from short circuits and provide additional contact reliability.

Mass switch - price and other features of the device

With its help, a yacht, boat or boat is disconnected from the electrical supply system in one motion. Thus, it is possible to protect the ship’s electrical equipment from short circuits during repair work or parking lots. Plus the battery discharges much more slowly. Using the built-in voltmeter or ammeter, it is convenient to monitor battery consumption.

The most common types:

• Mechanical with manual control;
• Automatic - the action occurs simultaneously with the engine starting;
• Electromagnetic or electric - activated by a special button or toggle switch;
• Electronic - control via a special board;

The most convenient is the model with a button on the panel or control panel. If the device is not included in the initial configuration of the vessel, the issue can be resolved by purchasing a remote device. The device itself is inexpensive, and its price is determined primarily by the features of the small vessel.

In the online store “1000 sizes”, with the help of experienced consultants, you will quickly find your way around a wide range of switches and select the option that suits all parameters. All types of electrical equipment are protected by the manufacturer's warranty and are carefully checked before shipment.

A common question is how to connect the car's ground switch. After all, not everyone modern car has such useful function. And people regularly encounter dead batteries after parking for several days. After all, a car has a lot of different equipment that is constantly connected to the battery. And even in economy mode, energy consumption is constant.

Also, the risk of electrical equipment breakdowns and current leakage through damage to the insulation cannot be excluded. In all these cases, such a switch will not be superfluous, so experienced car enthusiasts recommend installing such a device in the car.

How to connect the vehicle's ground switch? Before asking this question, you should determine where to put it. Most often, the button is installed near the battery, this allows you to significantly reduce the length of the “mass” wire. Most modern button models are of the remote type. Stores often offer buttons that are combined with a negative terminal; this is the most convenient option.

What will you need?

To install you will need the following things:

• Mass off button;
• Wires with a cross section of 5-10 mm;
• Crimp connectors;
• Seal from the mirror;
• Negative terminal for battery;
• Hot glue gun;
• Fuse.

Installation

Before installation, you need to take into account that you will have to work with an electrician, so evaluate your capabilities. If possible, consult or ask for help from a more experienced person. Installation is done as follows:

• Disconnect the battery, this will avoid a short circuit. Remove the negative wire;
• A place for the button is selected, and holes for its fastening are drilled in this place. Usually you need to drill 2-3 holes;
• Next there are 2 options. The first is to use the wire already on the battery, but in this case, you will have to carefully select the location of the button. The second option uses a new wire. A terminal is attached to it. On the other side, a crimp connector is installed. With this method, you can install the switch in any convenient place;
• We take the wire and crimp it on both sides into the mounting connectors;
• We install the button in its proper place;
• Connect the wires to the button. The wire from the terminal is connected to “-B”;
• The next step is to screw the second free wire to ground.

After that, all that remains is to check the operation of the button.

Connecting ground to bypass the alarm

If you want to use the ground shutdown with simultaneous work alarms. So, you'll have to tinker a little. An additional wire is attached to the negative terminal; for this purpose, you can choose one that is not too thick. A fuse is cut into it, and this structure is screwed to the body.

This will be enough for the alarm to work, but when you try to start the engine or turn on any other equipment, the fuse will simply burn out. Thus, if the ground is connected, it will not be possible to start the engine; any attempt will simply de-energize the car.

Terminal care

To maintain battery terminals in working condition, it is necessary to take proper care of them in a timely manner. To do this, do the following:

• Remove the battery;
• Prepare a strong solution of baking soda. The terminals are lowered into it. You should keep them in the solution for about 5 minutes. During this time, bubbles can be seen rising from the metal. The terminals are removed when the bubbles stop flowing;
• The removed terminals are inspected; they should not be severely damaged by corrosion. Wipe the terminals;
• Apply special lubricant or technical petroleum jelly to the contact points.

Prevention should be carried out at least 2 times a year. Experienced motorists recommend doing this in spring and autumn.

In some cases, connecting ground is simply not possible. The reason is the features technical characteristics cars. In some modern cars The engine control unit does not respond well to being disconnected from the power supply. In this case, he begins to suspect a malfunction, and after the power is returned, he simply begins testing, preventing the engine from starting.

To avoid such problems, before installing the switch, study the features of the vehicle's electrical system. If necessary, you can apply a negative voltage to the block using a wire and a fuse.

Conclusion. Many car enthusiasts regularly turn off the power to their car for various reasons. Usually, to do this, remove one of the terminals from the battery. But, having exhausted themselves with this everyday procedure, they begin to wonder how to connect the car's ground switch. In fact, it's all quite simple, you just need to choose the right place and connect everything carefully.

I read the comments. Apparently, most people know about circuit breakers that they exist. How they work or their parameters is a completely dark forest. Moreover, there is not even knowledge from Wikipedia.
And instead of creating a bunch of comments, I’ll write one big one.

For the author
I’m not the first to write - such a discharge of the battery is abnormal. We need to look for the problem.
And as noted below, the generator current may well be greater than the maximum permissible long-term current for the machine (in in this case 71.2A).

Battery
Here's more general information:

ish

Well, the starting current indicated on the battery is 640A, apparently it doesn’t bother the author either

This is the nameplate limit value of the battery. This is not the value that you need to focus on in this case.

sergku1213

Again, the discharged part of the battery (even 13%) in the cold begins to undergo sulfation, that is, irreversible degradation of the battery.

Is not a fact. There was a battery lying around at our university that had been standing in an unheated room for 2 or 3 years (remnants of old research). Its capacity was only 10% of the nominal value.
As a result of repeated charges/discharges with a very low current, it was possible to bring it back to life with a capacity of 95%. They drove it for another week and there was no drop in capacity. Then they disposed of it.
Sulfation is not irreversible, but in terms of time it is pointless (1.5 months of constant charges/discharges were spent on restoration).

Switch

A little theory.
Each automaton labeled A, B, C, D, K and Z has certain exact values ​​(). I will focus on B, C, D, as the most frequently encountered and applicable (the rest are often developed by companies for specific purposes).
Each switch has two categories of two main indicators according to international standards:

Overload current
- Short circuit current

Index:

Maximum failure current
- Minimum current guaranteed operation

In general, these values ​​are as follows for overload after 1 hour (thermal energy triggering) for circuit breakers up to 63A (type B,C,D)
Maximum failure current = 1.13 rated current
Minimum guaranteed operation current = 1.45 rated current

For short circuits, these values ​​differ for switches (so-called electromagnetic tripping without delay):
type B - 3*In and 5*In
type C - 5*In and 10*In
type D - 10*In and 20*In

No one can or will guarantee what happens between the lines. In principle, the switch can operate immediately from the minimum value or not operate until the maximum. And you need to look based on your own requirements.

Example of current-time lines of 63 A circuit breakers from Siemens B, C, D series 5SY

Now for the errors in the comments:

kvazimoda24, george_vernin

Speaking about current, first of all we are talking about the protective function of the machine itself. It is rated for 63 amps and at higher currents, it will open the circuit

It won’t go out - it will need more than 100 amperes in this mode - electromagnetic protection.

There the value is even greater, the figures are given above.

Valerij56

But after several operations, the “sensitivity” of the thermal relay may increase.

After several operations in a row - it is possible, but if we are talking about “it worked, turned it on - everything is in order”, then the behavior will not change during the declared period of operation (should not be the case with a normal manufacturer).
Valerij56

But, firstly, they are not available in all machines, and secondly, they work at least ten times more than the nominal value, so if it doesn’t work, then everything is in order.

Depends on the letter of the machine, I described in detail above.

DMGarikk

Doesn't it bother you that the starter current is more than 200A maybe?

Impuls

installing a machine at 60 amperes, while starting currents can reach 200-300 amperes, is not the right decision.

The starting current for C63A can be no more than 315 A. This is exactly how they often set it (after all, he must also turn off the short circuit, so D is not always suitable).

BigBeaver, Ezhyg

That is, if you put a 64 A / 12 V switch into a network with a voltage of 230 Volts and a consumer eating 64 Amps, nothing will change?

I didn't say that. To be precise, there is not enough data to answer this.

MEG123

The machine is designed for alternating current, this is the same as a constant in a car, but variable.

The link I provided above to ABB (this one) describes the S200 series machines, which can be used in direct current voltage from 24V. The only thing is that the electromagnetic trigger operates for currents 1.5 times higher.
In principle, almost any machine can be used without problems at 60V from major manufacturer no problem. In the case of ABB - from 24V.

MEG123

150A, depending on the letter on the machine it will be knocked out either with a 50% probability or with a 100% probability on such a starter.

You can take a look at the chart above from Siemens. Such a machine can knock out after 7 seconds at 150 A regardless from the letter.

MEG123

on this collective farm it will easily drop a couple of volts if you turn on all the lights and heating

The resistance of a 63A machine is somewhere around 0.003-0.004 Ohm. At 200 A this is 0.8V. It's unpleasant, but as long as the battery is new, it's not critical.

MEG123

Regular machine designed for a supply cable with a cross-section of 6-10 squares, the mass leaving the battery is about 25-40 squares, i.e. in order to stuff it into the machine, I obviously had to cut the cross-section of the wire

What about Google? As a rule, a 63A circuit breaker allows you to connect up to 35 mm² single-core or 25 mm² multi-core. Your 6-10 is for machines with 16A-25A, maybe 40A (but only with open routing of cables and wires, since the machine must protect the wire from overload).

Serge3leo

The C63 circuit breaker goes back and forth, it operates within 10 s at currents of 315...630A.

Siemens has up to 10 seconds in the version above (5SY switch), here you need to look at a specific manufacturer or even the lineup(Siemens also has longer ones for the same letters, but they are few).