There are two main types of stacked energy storage systems: low voltage stacking and high voltage stacking. Although both serve the same purpose, they are very different. Let's examine these differences:
Voltage levels: Low voltage stacking typically refers to systems operating below 48V (51.2V), consisting of 16 cells connected in series. High voltage stacking, on the other hand, operates within a voltage range of 48V (excluding) to 800V.
Design complexity: High voltage stacking requires DC-DC converters to boost the battery output voltage to match the AC inverter input, adding to the complexity and cost of the design. Conversely, low voltage stacking does not require a converter as the battery output voltage is already compatible with the inverter input, making the design simpler and more cost effective.
Module connection methods: In high voltage stacking, modules are connected in series, increasing the voltage while keeping the battery capacity constant. In low voltage stacking, the modules are connected in parallel, increasing the capacity at the same voltage.
Safety requirements: High voltage systems require higher safety standards due to the use of high voltage batteries. Low voltage systems using low voltage batteries have relatively lower safety requirements.
Scalability: High voltage stacking systems usually have a minimum unit of three or four module sets in series. Low voltage stacking systems can start with a single set of modules, offering greater flexibility in scalability.
Energy conversion: Low-voltage stacking solutions incur energy losses during current transfer, whereas high-voltage systems reduce energy losses by lowering the current value. For example, from the same 10kWh of energy, a high-voltage solution can deliver 1-2kWh more than a low-voltage solution.
In addition, high-voltage systems charge and discharge more efficiently and can handle higher energy densities, making them suitable for large-scale energy storage. Low voltage systems are better suited to smaller applications, such as home energy storage.
Conclusion
The choice between high and low voltage systems depends on your application requirements and the amount of energy storage needed. The Sunpack Home Energy Storage battery range offers both high and low voltage stacking options, allowing flexible battery capacity matching and high scalability. We utilize top-quality A-grade lithium iron phosphate battery cells boasting an impressive 6,000+ charge cycles. Our independently developed BMS provides multi-level battery protection for added peace of mind. Plus, our product features RS485/RS232/CAN communication and is fully compatible with a variety of energy storage inverters on the market, allowing us to cater to the unique needs of each user.
