Use of High-voltage Batteries in Electric Cars and Solar Systems

What is A High-voltage Battery？

High voltage batteries provide high energy density and also a high discharge plateau. They likewise supply a lot more ability under the exact same usage problems, so they last much longer while delivering even more power. Normally, BSLBATT ESS high voltage batteries will last 15-25% longer.

 ● The complying with sums up the benefits of using our high-voltage batteries.

 ● High power thickness and longer battery life: 15% more than regular batteries.

 ● High as well as stable discharge plateau: constant use does not affect battery life as high as with normal batteries.

 ● A battery that can still deliver 80% of its initial capacity also after 400 cycles

 ● Based upon practical applications, the battery can still fulfill a minimum of 3 years of service life, operate at low and high temperature levels, and also meet various multiplier requirements in the power sector.

 ● Can be mass-produce as well as have excellent battery uniformity.

How Do High-voltage Batteries Work? What Are Their Advantages in Operation with A PV System?

Functional Principle of High-voltage Batteries in Electric Cars

Along with the electric motor, the high-voltage (HV) battery is one of the key components of the electric and electric hybrid vehicle. Although the technology is already suitable for everyday use, the high energy density in a confined space can lead to short circuits and fires. Research is therefore continuing into materials for the high-voltage battery that do not trigger unwanted chemical reactions. In addition, further research is worthwhile because without a high-voltage battery, the production of an electric car would be as expensive as that of a diesel or gasoline vehicle. This is because the price premium of several thousand euros comes from the high-voltage battery alone.

Today's high-voltage vehicles usually have a three-phase machine that serves as both a motor and a generator. In generator mode, the three-phase machine generates 3-phase alternating current (AC) like conventional generators or alternators, but with significantly higher voltages. In motor operation, the three-phase machine is fed with a 3-phase AC voltage and the speeds are controlled by varying the frequency of the 3-phase AC voltage.

Metal hydride batteries are mainly used here, as well as lithium-ion batteries in some cases. In the modules of the high-voltage batteries, individual cells with a voltage of one to two volts are then connected in series. In total, this results in the required high-voltage.

The inverter converts the 3-phase AC voltage of the generator into a DC voltage for charging the battery or the DC voltage of the battery into a 3-phase AC voltage for driving the electric motor. In the DC/DC converter, the high-voltage of the high-voltage battery is lowered accordingly for charging the "12 V battery".

Integration of High-voltage Batteries in Photovoltaic Systems

Recently, the advantages of a high-voltage battery have also been tapped with an appropriately adapted solar inverter. This is because the high voltage level of the high-voltage battery allows it to be connected directly to an intermediate circuit of the inverter, so that with the very wide input voltage range of 150 to 1,000 volts and corresponding maximum power trackers, almost any combination of series connections and alignments of solar modules can be served.

Solar installations on east-west oriented roofs as well as on roofs partially shaded during the day could especially benefit from the wide-ranging freedom in connecting the modules into different strings. Since the high-voltage storage system (> 350 V) is connected directly to a DC link of the feed-in inverter, particularly high efficiencies can be achieved during charging and discharging from the battery. In addition, the direct connection of the battery to the feed-in inverter can save costs for the connection components in the photovoltaic battery storage systems offered today.

SMA Solar Technology AG was one of the first manufacturers to launch a battery inverter for private households that is adapted to high-voltage batteries. The AC-coupled "Sunny Boy Storage" system enables simple and flexible integration of an electricity storage system into both existing and new photovoltaic systems, as the SMA high-voltage inverter system runs in parallel with the photovoltaic system and therefore does not need to intervene in the photovoltaic system.

Due to the AC coupling of the high-voltage battery storage and standardized interfaces, the system can be adapted and expanded to individual needs at any time, even after installation, due to changed life circumstances such as the integration of an electric vehicle as well as a change in own energy demand. According to SMA, the storage costs per kWh of the high-voltage battery should be at the level of average German household electricity prices.

High Voltage (HV) Battery Storage System

High-voltage technology is a relatively new concept in lithium battery storage technologies. Each lithium battery module has a voltage of 48 volts. In a high-voltage storage system, there are several lithium batteries with a total voltage of 200 - 500 volts. This is created by connecting the individual lithium battery modules in series. This high output voltage results in a higher efficiency, which is due to the reduction of conversion losses. If a high-voltage battery is installed with a hybrid inverter, a very efficient storage system can be built.

In high-voltage systems (inverter + battery), the efficiency of the system increases with the number of high-voltage battery modules, as they are connected in series. The more battery modules, the higher the input voltage for the battery inverter. As a result, the efficiencies for the large storage capacities are better than those for the small storage systems of the same series. Depending on the capacity of the high-voltage battery, you should ask about the specific efficiency!