Five steps to ensure battery quality – pv magazine International

High quality never happens by chance. It is always the result of comprehensive, well thought out, and concerted effort. For Growatt, quality is the lifeline spanning the company’s entire spectrum of operations and extensive portfolio of products, including PV inverters, energy storage systems, EV chargers, and smart energy management solutions.

The Shenzhen-based manufacturer first promoted its storage products back in 2015 and has since expanded its portfolio to include a variety of DC- and AC-coupled solutions for residential and small commercial use. At the end of 2021, Growatt had delivered around 3.8 million sets of its PV inverter and battery systems.

Cutting-edge production

Growatt’s battery manufacturing is co-located with its PV inverter production in Huizhou, China. Spread over approximately 200,000 square metres, its manufacturing facility has an annual capacity of 20 GW of PV inverters and 400,000 battery modules. Faithful to the lithium iron phosphate (LFP) chemistry because of its extreme safety, Growatt has released multiple models of its branded battery energy storage systems, such as AXE, Hope, GBLI and the ARK series.

All of Growatt’s battery systems have gained a good reputation in the market thanks to high quality and reliability, not to mention confirmation by independent testing service providers. Last year, Growatt’s modular ARK residential battery energy storage solution achieved outstanding performance in TÜV Rheinland’s rigorous safety and reliability tests and won the prestigious All Quality Matters Award. As might be expected, for Growatt, quality is all that matters.

“Growatt would never compromise on quality, even under the cost pressure,” says Ray Cheng, head of overseas marketing at Growatt. “We’re very certain the high quality of products can bring cost savings for the company in different ways, such as through reducing maintenance cost or saving marketing costs that occur due to any quality defects.”

Step by step

To deliver top-notch reliability and performance, Growatt strictly executes its tested Five Step Quality System for the new product development and mass production process. The first step of the systematic quality program is Component Engineering. At this stage, Growatt conducts safety tests for the battery cell and module, including over-charge, over-discharge, short circuit, dropping test, thermal runaway test, extrusion test, seawater immersion test, temperature changing test, low air-pressure test , and the shaking test with the goal to ensure that fire, explosion, or leakage accidents do not happen under the worst conditions.

For instance, in the thermal runaway testing, a heating element is placed near a battery cell exposing it to temperatures up to 215 C. As soon as the heat is spread to the adjacent battery cell, an explosion-proof valve will open, preventing fire .

For the second step, Design Engineering, Growatt conducts a variety of engineering verification tests, including state-of-charge (SoC) and state-of-health (SoH), to verify the charge and discharge accuracy under different C rates and temperatures, alongside charge/discharge switch tests. In addition, the battery management system (BMS) test and the state of power (SOP) algorithm import test are also critical for the battery.

The BMS is the brain of the system and the first in line to provide full protection in cases of over/under temperature, over/under voltage, over current, and short circuiting. One of the critical parts of the BMS test is real-time data collection, covering temperature, SoC, cell and pack voltage, charge and discharge current sampling and other parameters, giving a comprehensive picture of the battery’s status and health at any given moment.

Next comes the design verification test stage, in this Growatt assembles the energy storage system and combines inverters, batteries, and monitoring devices to verify that all the elements work seamlessly as a whole under various external conditions.

For the fourth step, Environment and Reliability Engineering in the trial-run and validation stage, Growatt conducts long-term charge and discharge cycle tests and capacity and conformance tests to assess battery status in the full life cycle. In addition, it runs the ecological application tests to guarantee that the whole system is operating reliably in different application scenarios.

The Manufacturing Engineering stage focuses on both product launch and mass production. In the product launch stage, the manufacturer conducts product audit tests, such as the type test, capacity audit test, and conformance test. Overall, there will be at least 128 testing steps for the battery product development, ensuring an exhaustive and extensive quality assurance process.

On top of the rigorous in-house regime, all battery storage products made by Growatt are also subject to the third-party verification tests to achieve global certifications such as CE, IEC 62619, VDE 2510, UL1973, UL9549, UN38.3 MSDS, and more. Finally, for the mass production stage, Growatt cutting-edge manufacturing facility has achieved quality management system certificates ISO 9001, ISO14001 and ISO 45001. In addition, the manufacturer conducts full tests for the whole manufacturing process, including IQC inspection, module test, aging test, air tightness test, and package test to deliver superior quality products and excellent customer experience.

This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: editors@pv-magazine.com.

Leave a Comment