HHS Stackable Battery
HHS stackable battery provides large energy storage capacity and power output capabilities. It consists of multiple battery modules and battery management system (BMS). It is highly scalable to meet various power requirements.
The EMS constantly monitors the grid demand and transfers energy to the BMS to meet the requirement. It also leverages data logging to improve SOC estimation.
Features
The HomeGrid Stack’d Series is a residential battery designed to meet the needs of a variety of storage applications. From off-grid cabins to peak rate TOU offset, family homes in suburbia and small commercial projects — our battery provides the right combination of output, capacity and durability for the job.
Each Stack features an in-built BMS that monitors and manages information about the battery HHS stackable battery cell, including voltage, current and temperature. The BMS can also balance charge and discharge state to extend cycle life and maximize performance. Multiple Stacks can be connected in parallel to expand output and capacity.
Each battery module is built using non-toxic, pollution-free lithium iron phosphate cathode material with high safety and power performance. Its cellular structure ensures that the cathode and anode materials are always in contact to deliver consistent, quality energy. The battery is environmentally-friendly, has low emissions, is non-flammable and operates safely in a wide operating temperature range.
The Battery Management System (BMS) is located at the top of each battery module and monitors battery information, protects against over-charge, over-discharge, over-current, high/low temperatures and balancing current and voltage between cells. It also supports communication with external devices. The modular design of each Stack means that the BMS is easily installed within your system, with no extra wires or bus bars needed between modules.
Capacity
A battery’s capacity is a measure of its ability to power devices for a certain amount of time. It is usually rated in kilowatt-hours (kWh) and is a key energy metric when comparing products. The higher the capacity, the more devices it can power for longer periods of time.
A critical issue with BESS is performance degradation due to aging processes (capacity fade and internal resistance increase). It is essential to monitor battery State of Health (SOH) as well as the overall system operation to extract maximum possible value from the stationary storage system.
It is also important to note that only a passive or active battery cell balancing system can significantly reduce energy losses. ADI’s LTC6811 BMS is a cost-effective, patented active balancer solution that uses a flyback topology to return charge to the cell stack from an auxiliary power rail. This allows the weaker cells in the stack to redistribute charge from stronger ones during a charging cycle, improving the battery performance.
There are a number of publicly available modeling tools for technical and economic analysis of BESS systems. HOMER (Hybrid Optimization of Multiple Energy Resources) developed by NREL is an excellent example and features detailed efficiency, power and energy density models that can be parameterized using data sheets for the various battery sub-components. Another tool is SAM (System Advisor Model), which provides straightforward techno-economic analysis for MG featuring fossil generation, renewables, storage and load management.
Safety
The organic liquid electrolyte inside LIBs is intrinsically flammable, and this is the main reason behind many battery failures that lead to fires. This phenomenon is called thermal runaway, and it can be triggered by various factors including overcharging, external short circuits due to faulty wiring, cell crush such as metal debris penetration (in Tesla car accidents), or internal shorting caused by lithium dendrite formation under high current power-storage-brick density charging conditions or at low temperatures. It can also be triggered by defective separators created during battery assembly or by poor manufacturing processes.
The thermal runaway process has three stages. The onset of overheating in stage 1 causes the batteries to change from a normal to an abnormal state, and the internal temperature quickly starts to rise. In stage 2, the SEI decomposes, triggering more exothermic reactions and heating up the battery even further. Finally, in stage 3, the flammable electrolyte combusts, resulting in fires and explosions.
To improve safety, functional materials are designed to reduce the risk of thermal runaway. For example, a trilayer separator that contains silica nanoparticles sandwiched by two layers of commercial polyolefin separators consumes penetrating lithium dendrites and slows down their growth after they penetrate the separator, thereby significantly improving battery safety. In addition, the encapsulated triphenyl phosphate flame retardant is released into the electrolyte, suppressing the combustion of the flammable liquid.
Installation
With its Lego-like modular design, the Stack’d Series battery has a quick installation time of 30 min. There’s no conduit or wiring between modules, and the batteries are easily upgraded as power requirements grow.
The battery uses LiFePO4 chemistry, which is safe and offers higher cycle life than other lithium batteries. The BMS monitors cell information and balances current and voltage to help extend the battery’s lifetime. Multiple battery modules can be stacked in parallel to expand output and capacity.
The Stack’d Series battery comes with an outdoor case that’s IP65/NEMA3R rated. It protects the battery from direct weather and has UV-resistant plexiglass for viewing the BMS LCD, water-proof vents to manage temperature, holes in the base for ground-mounting, and a security hole for a padlock. This battery also features a high output voltage of 260-400v, making it easier to pair with HV inverters. The Stack’d Series is a great option for off-grid cabins, peak rate TOU (time of use) offset, and residential/commercial projects.
