1
Fast charging
Compared with nickel-metal hydride and lithium-ion power batteries with good development prospects, traditional lead-acid batteries are Mature,
low cost, large battery capacity, good load following output characteristics and no memory effect, etc., but there are also low specific energy,
short driving range on a single charge. question. Therefore, in the current situation where power batteries cannot directly provide more driving range,
If battery charging can be achieved quickly, it will in a sense solve the fatal problem of short driving range of electric vehicles. Weak
point.
2
. Universal charging
In the context of the market where multiple types of batteries and multiple voltage levels exist, it is used in public ** *The charging device in the place must
have the ability to adapt to multiple types of battery systems and adapt to various voltage levels. That is, the charging system needs to be versatile in charging and have multiple types of batteries. The charging control algorithm can match the charging characteristics of different battery systems on various types of electric vehicles, and can charge different batteries. Therefore, in the early stage of commercialization of electric vehicles, relevant policies and measures should be formulated to standardize the charging interfaces, charging specifications and interface protocols of charging devices used in public places and electric vehicles
Wait.
3
Intelligent charging
One of the most critical issues restricting the development and popularization of electric vehicles is the performance and application level of energy storage batteries. The goal of optimizing the intelligent battery charging method is to achieve lossless battery charging, monitor the battery's discharge status, and avoid over-discharge, thereby extending the battery's service life. and energy saving purposes. The development of intelligent charging application technology is mainly reflected in the following aspects:
●Optimized, intelligent charging technology, chargers and charging stations
;
p>
●Battery power calculation, guidance and intelligent management
;
●Automatic diagnosis and maintenance technology of battery faults, etc.
4
High efficiency of electric energy conversion
The energy consumption indicators of electric vehicles are closely related to their operating energy costs. Reducing the operating energy consumption of electric vehicles and improving their economics are one of the key factors in promoting the industrialization of electric vehicles. For charging stations, considering the power conversion efficiency and construction cost, priority should be given to charging devices with many advantages such as high power conversion efficiency and low construction cost.
5
Charging integration
In line with the requirements for miniaturization and multi-function of subsystems, as well as the improvement of battery reliability and stability requirements, The charging system
will be integrated with the electric vehicle energy management system as a whole, integrating functions such as transmission transistors, current detection and reverse discharge protection
without external components. A smaller and more integrated charging solution can save layout space for the remaining components of electric vehicles, greatly reduce system costs, optimize charging effects, and extend battery life
Battery Charging
Solutions
In fact, all
3G
mobile phones use lithium-ion batteries as the main power source. Due to heat dissipation and space constraints, designers must
carefully consider what type of battery charger to choose and what features are needed to ensure safe and accurate charging of batteries
.
An obvious trend for linear lithium-ion battery chargers is that package size continues to decrease. But what is worth paying attention to is the cooling during the charging cycle
(
Especially during the high current stage
)
Cooling
IC
Required board space or ventilation.
The power consumption of the charger will increase the temperature of the junction of the IC
. Combined with ambient temperature, it can reach high enough levels to overheat the
IC
and reduce circuit reliability. Additionally, many chargers will stop the charge cycle if they overheat, only to resume operation when the junction temperature drops. If this high temperature persists, the charger's repeated "stop and start" cycles will continue to occur, extending charging time.
To reduce these risks, users can only choose to reduce the charging current to extend the charging time or increase the board area to dissipate heat. Therefore,
due to the increase in
PCB
heat dissipation area and thermal protection materials, the cost of the entire system will also increase.
There are two solutions to this problem. First, there is a need for a smart linear lithium-ion battery charger that does not have to sacrifice PCB area for the worry of
heat dissipation and uses a small The thermally enhanced package allows it to monitor its own junction temperature to prevent overheating. If a preset temperature threshold is reached, the charger can automatically reduce charging current to limit power consumption, keeping the chip temperature at a safe level. The second solution is to use a charger that generates almost no heat even at high charging currents. This requires the use of a pulse charger, which is a completely different technology than linear chargers. Pulse chargers rely
on a well-regulated, current-limited wall adapter to charge.
Option 1
LTC4059A
Linear battery charger
LTC4059A
is a single-cell A linear charger for lithium-ion batteries that does not require the use of three discrete power devices and can be charged quickly without worrying about system overheating. The monitor is responsible for reporting the charging current value and indicating when the charger is connected to the input power source. It comes in the smallest possible package without sacrificing thermal performance. The entire solution requires only two discrete components
(
Input
capacitor and a charging current programming resistor
)
, the footprint is
2.5mm
×
2.7mm
LTC4059A
adopted
2mm
×
2mm
DFN
package, occupying only
SOT-23
Half the package and can provide approximately
60
℃
/W
Low thermal resistance to improve heat dissipation
efficiency. With proper
PCB
layout and heat dissipation design,
LTC4059A
can operate at an input voltage of
Safely charge a single-cell lithium-ion battery at 5V
with a maximum current of
900mA
. In addition, there is no need to consider worst-case power consumption when designing, because
LTC4059A
adopts patented thermal management technology that can operate under high-power conditions.
(
If the ambient temperature is too high
)
The charging current will be automatically reduced
.
Option 2
: LTC4052 with overcurrent protection function
Pulse charger