The car emergency starting power supply is a multifunctional portable mobile power supply developed for car lovers and business people who drive and travel. Its characteristic function is to start the car when it loses electricity or cannot start the car for other reasons. At the same time, the air pump is combined with emergency power supply, outdoor lighting and other functions, which is one of the essential products for outdoor travel.
Car emergency starting power: Car Jump Starter
Life applications: cars, mobile phones, notebooks
Product features: standard LED super bright white light
Advantages: high rate discharge, recycling, portable
Battery type: lead-acid battery, winding battery, lithium ion battery
Brief introduction of automobile starting power supply:
The design concept of automobile emergency starting power supply is easy to operate, convenient to carry, and able to respond to various emergency situations. At present, there are mainly two kinds of emergency starting power supplies for automobiles on the market, one is lead-acid battery type and the other is lithium polymer type.
The lead-acid battery type of automobile emergency starting power source is more traditional. It uses maintenance-free lead-acid batteries, which are relatively large in mass and volume, and the corresponding battery capacity and starting current will also be relatively large. This type of product is generally equipped with an air pump, and also has functions such as overcurrent, overload, overcharge and reverse connection indication protection, which can charge various electronic products, and some products also have functions such as inverters.
Lithium polymer emergency starting power supplies for automobiles are relatively trendy. It is a product that has appeared recently. It is light in weight and compact in size and can be controlled with one hand. This kind of product is generally not equipped with an air pump, has an overcharge shutdown function, and has a relatively powerful lighting function, which can supply power for various electronic products. The lighting of this type of product generally has the function of flashing or SOS remote LED rescue signal light, which is more practical.
Life application:
1. Cars: There are many types of lead-acid battery start-up currents, and the approximate range is 350-1000 amperes. The maximum current for lithium-polymer start-up cars should be 300-400 amperes. In order to provide convenience, the car's emergency starting power supply is compact, portable and durable. It is a good helper for emergency starting of the car. It can provide auxiliary starting power for most vehicles and a small number of ships. It can also be used as a portable 12V DC power supply to prepare for the car. Used in emergency situations.
2. Notebook: The multifunctional car emergency starting power supply has a 19V voltage output, which can provide a stable power supply voltage for the notebook to ensure that some business people go out and reduce the battery life of the notebook. Generally speaking, 12000 mAh polymer batteries should be able to work. Provide 240 minutes of battery life for the notebook.
3. Mobile phone: The car's starter power supply is also equipped with a 5V power output, and more supports battery life for a variety of entertainment devices such as mobile phones, PAD, and MP3.
4. Inflation: Equipped with an air pump and three kinds of air nozzles, which can inflate car tires, inflation valves, and various balls.
Types and characteristics:
At present, the following types of emergency start power sources are mainly used in the world, but no matter which type, they have higher requirements for discharge rate. For example, the current of lead-acid batteries in electric bicycles and lithium batteries in mobile phone chargers is far from enough to start a car.
1. Lead acid:
a. Traditional flat lead-acid batteries: The advantages are low price, extensive durability, high temperature safety; disadvantages are bulky, frequent charging and maintenance, dilute sulfuric acid is easy to leak or dry out, and can not be used at low temperatures below 0°C.
b. Coiled battery: The advantage is that it is cheap, compact and portable, safe at high temperature, can be used below -10°C, simple maintenance, and long life; the disadvantage is that it is relatively large in size and weight, and has less functions than lithium batteries.
2. Lithium ion:
a. Polymer lithium cobalt oxide battery: The advantages are small, beautiful, multifunctional, portable, and long standby time; the disadvantages are high temperature explosion, low temperature unusable, complex protection circuit, no overload, small capacity, high quality products are expensive.
b. Lithium iron phosphate battery: The advantages are small and portable, beautiful, long standby time, long life, higher temperature resistance than polymer batteries, and can be used at low temperatures below -10°C; the disadvantage is that high temperatures above 70°C are unsafe and the protection circuit is complicated. The capacity is smaller than that of wound batteries and the price is more expensive than polymer batteries.
3. Capacitors:
Supercapacitor: The advantages are small and portable, the discharge current is large, the charging is fast, and the life is long; the disadvantage is that the high temperature above 70 ℃ is not safe, the protection circuit is complicated, the capacity is the smallest, and the price is extremely expensive.
Product features:
1. The car emergency starting power supply can ignite all cars with 12V battery output, but the applicable product range of cars with different displacements will be different, and it can provide services such as field emergency rescue;
2. Standard LED super bright white light, flickering warning light, and SOS signal light, a good helper for travel;
3. The car emergency start power supply not only supports car emergency start, but also supports a variety of outputs, including 5V output (supporting all kinds of mobile products such as mobile phones), 12V output (supporting routers and other products), 19V output (supporting most laptop products) ), increasing the wide range of applications in life;
4. The car's emergency starting power supply has a built-in maintenance-free lead-acid battery, and there is also a high-performance polymer lithium-ion battery, with a wide range of options;
5. Lithium-ion polymer vehicle emergency start-up power supply has a long service life, charging and discharging cycles can reach more than 500 times, and it can start the car 20 times when it is fully charged (the battery is displayed in 5 bars) (the author uses this, not all brands);
6. The lead-acid battery emergency start power supply is equipped with an air pump with a pressure of 120PSI (pictured model), which can facilitate inflation.
7. Special note: The battery level of the lithium-ion polymer emergency starting power supply must be displayed above 3 grids before the car can be ignited, so as not to burn the car's emergency starting power host. Just remember to charge it.
Instructions:
1. Pull up the manual brake, place the clutch in neutral, check the starter switch, it should be in the OFF position.
2. Please place the emergency starter on a stable ground or a non-moving platform, away from the engine and belts.
3. Connect the red positive clip (+) of the "emergency starter" to the positive electrode of the battery that lacks power. And make sure the connection is firm.
4. Connect the black accessory clip (-) of the "emergency starter" to the grounding pole of the car, and make sure the connection is firm.
5. Check the correctness and firmness of the connection.
6. Start the car (no more than 5 seconds). If a start is not successful, please wait for more than 5 seconds.
7. After success, remove the negative clamp from the grounding pole.
8. Remove the red positive clip of the "emergency starter" (commonly known as "Cross River Dragon") from the positive terminal of the battery.
9. Please charge the battery after use.
Start power charging:
Please use the supplied special electric appliance for charging. Before using it for the first time, please charge the device for 12 hours. The lithium-ion polymer battery usually can be fully charged in 4 hours. It is not as long as it is said before. Maintenance-free lead-acid batteries require different charging times depending on the capacity of the product, but the charging time is often longer than that of lithium polymer batteries.
Lithium polymer charging steps:
1. Insert the supplied charging cable female plug into the "emergency starter" charging connection port and confirm it is secure.
2. Plug the other end of the charging cable into the mains socket and confirm it is secure. (220V)
3. At this time, the charging indicator will light up, indicating that charging is in progress.
4. After the charging is completed, the indicator light is turned off and left for 1 hour to detect that the battery voltage reaches the requirement, which means it is fully charged.
5. The charging time should not be longer than 24 hours.
Maintenance-free lead-acid battery charging steps:
1. Insert the supplied charging cable female plug into the "emergency starter" charging connection port and confirm it is secure.
2. Plug the other end of the charging cable into the mains socket and confirm it is secure. (220V)
3. At this time, the charging indicator will light up, indicating that charging is in progress.
4. After the indicator light turns green, it means charging is complete.
5. It is recommended to charge for a long time for the first use.
Recycle:
In order to reach the maximum service life of the car's starting power supply, it is recommended to keep the machine fully charged at all times. If the power supply is not kept fully charged, the life of the power supply will be shortened. If not in use, please ensure that it is charged and discharged every 3 months .
The basic principle:
The power architecture of most cars must follow the most basic principles when designing, but not every designer has a thorough understanding of these principles. The following are the six basic principles that need to be followed when designing automotive power architecture.
1. Input voltage VIN range: the transient range of the 12V battery voltage determines the input voltage range of the power conversion IC
The typical car battery voltage range is 9V to 16V. When the engine is off, the nominal voltage of the car battery is 12V; when the engine is working, the battery voltage is around 14.4V. However, under different conditions, the transient voltage may also reach ±100V. The ISO7637-1 industry standard defines the voltage fluctuation range of automotive batteries. The waveforms shown in Figure 1 and Figure 2 are part of the waveforms given by the ISO7637 standard. The figure shows the critical conditions that high-voltage automotive power converters need to meet. In addition to ISO7637-1, there are some battery operating ranges and environments defined for gas engines. Most of the new specifications are proposed by different OEM manufacturers and do not necessarily follow industry standards. However, any new standard requires the system to have overvoltage and undervoltage protection.
2. Heat dissipation considerations: heat dissipation needs to be designed according to the lowest efficiency of the DC-DC converter
For applications with poor air circulation or even no air circulation, if the ambient temperature is high (> 30°C) and there is a heat source (> 1W) in the enclosure, the device will quickly heat up (> 85°C). For example, most audio amplifiers need to be installed on heat sinks and need to provide good air circulation conditions to dissipate heat. In addition, the PCB material and a certain copper-clad area help to improve the heat transfer efficiency, so as to achieve the best heat dissipation conditions. If a heat sink is not used, the heat dissipation capacity of the exposed pad on the package is limited to 2W to 3W (85°C). As the ambient temperature increases, the heat dissipation capacity will decrease significantly.
When the battery voltage is converted into a low voltage (for example: 3.3V) output, the linear regulator will consume 75% of the input power, and the efficiency is extremely low. In order to provide 1W of output power, 3W of power will be consumed as heat. Limited by the ambient temperature and the case/junction thermal resistance, the 1W maximum output power will be significantly reduced. For most high voltage DC-DC converters, when the output current is in the range of 150mA to 200mA, LDO can provide a higher cost performance.
To convert the battery voltage to low voltage (for example: 3.3V), when the power reaches 3W, a high-end switching converter needs to be selected, which can provide an output power of more than 30W. This is exactly the reason why automotive power supply manufacturers usually choose switching power supply solutions and reject traditional LDO-based architectures.
3. Quiescent current (IQ) and shutdown current (ISD)
With the rapid increase in the number of electronic control units (ECUs) in automobiles, the total current consumed from the car's battery is also increasing. Even when the engine is turned off and the battery is exhausted, some ECU units still keep working. In order to ensure that the static operating current IQ is within the controllable range, most OEM manufacturers begin to limit the IQ of each ECU. For example, the EU requirement is: 100μA/ECU. Most EU automotive standards stipulate that the typical value of ECU IQ is less than 100μA. Devices that always keep working, such as CAN transceivers, real-time clocks, and current consumption of microcontrollers are the main considerations for ECU IQ. The power supply design needs to consider the minimum IQ budget.
4. Cost control: OEM manufacturers’ compromise between cost and specifications is an important factor affecting the power supply bill of materials
For mass-produced products, cost is an important factor to be considered in the design. PCB type, heat dissipation capability, package options and other design constraints are actually limited by the budget of a particular project. For example, using a 4-layer board FR4 and a single-layer board CM3, the heat dissipation capacity of the PCB will be very different.
The project budget will also lead to another constraint. Users can accept higher cost ECUs, but will not spend time and money on transforming traditional power supply designs. For some high-cost new development platforms, designers simply make some simple modifications to the unoptimized traditional power supply design.
5. Position/layout: PCB and component layout in power supply design will limit the overall performance of the power supply
Structural design, circuit board layout, noise sensitivity, multi-layer board interconnection issues, and other layout restrictions will restrict the design of high-chip integrated power supplies. The use of point-of-load power to generate all necessary power will also lead to high costs, and it is not ideal to integrate many components on a single chip. Power supply designers need to balance overall system performance, mechanical constraints, and cost according to specific project requirements.
6. Electromagnetic radiation
The time-varying electric field will produce electromagnetic radiation. The intensity of radiation depends on the frequency and amplitude of the field. The electromagnetic interference generated by one working circuit will directly affect another circuit. For example, the interference of radio channels may cause the airbag to malfunction. In order to avoid these negative effects, OEM manufacturers have established maximum electromagnetic radiation limits for ECU units.
In order to keep electromagnetic radiation (EMI) within the controlled range, the type, topology, selection of peripheral components, circuit board layout and shielding of the DC-DC converter are all very important. After years of accumulation, power IC designers have developed various techniques to limit EMI. External clock synchronization, operating frequency higher than AM modulation frequency band, built-in MOSFET, soft switching technology, spread spectrum technology, etc. are all EMI suppression solutions introduced in recent years.
