Growatt Battery: An Independent Review by Solar Choice

Background on Growatt – Company history

Growatt is a Chinese company that is best known for their popular solar inverters, although they have recently ventured into the solar battery market since 2019 with their first product being the GBLI6531.

They were founded in 2010 and manufacture residential, commercial and large-scale solar inverters. Based in Shenzhen, China, it didn’t take them long to gain a foothold in the inverter market and by mid 2011 they rose to become the country’s top inverter exporter.  They’ve manufactured and shipped over 1.7 million inverters to over 100 countries and regions around the world.  In 2012 they expanded into the Australian market and have an office based in Silverwater, NSW.

According to IHS Markit’s world inverter shipment ranking, they’ve been recognised as a top 3 single-phase inverter brand.  IHS Market is a British information provider that covers a wide range of data from a wide variety of industries from economic forecasting, finance and the solar PV industry.

Growatt’s research and development team has over 200 engineers, who are committed to their mission of providing clear and convenient access to green energy worldwide.

We’ve gone through an extensive analysis in providing you with informative information for those of you who are looking for an independent Growatt battery review in Australia.

Basics of the Growatt 6.5kWh Lithium Battery (GBLI6531/GBLI6532)

The Growatt GBLI6531 is a 6.5kWh lithium battery designed for residential energy storage with a rated discharge of 3.3kW. This battery is known for it’s compact size and easy installation. Built using Lithium Ion Phosphate (LiFePO4) known for it’s safety, low self-discharge and long life cycle and is commonly used by battery manufacturers.

It appears from Growatt’s website that they have recently released an updated version of this battery, the GBLI6532. We have reached out to Growatt Australia, and they have confirmed that the GBLI6531 is no longer available anymore.  From their datasheets, there doesn’t appear to be much material difference between the two models. The only notable improvement with the GBLI6532 is that the charging/discharging current has increased from a maximum of 96A to 104.2A. The GBLI6532 also has a slight improvement in working temperature from a maximum of 45°C to 50ºC.

These batteries are designed to be connected in parallel to expand the power of your solar PV system. A total of 2 batteries can be connected together, providing a total of 13kWh which means it can handle most residential applications but would place it on the lower end on the commercial side. A Battery Management System (BMS) controls and monitors the batteries giving the customer an online portal through which they can see and manage their energy use.

With IP55 protection against dust and water rating, this battery is fine with being installed indoors or outdoors. Just be keep in mind however the working temperature of the GBLI6532 is -10°C to 50°C so it can handle most Australian environments.

The battery is compatible with and specially developed for either the single-phase or three-phase Growatt battery inverters of the SP and SPH series. It can be installed during installation of a solar PV system or retrofitted.

Growatt Battery – Key Features

There are a number of features of the Growatt battery worth mentioning:

Temperature Management

The performance of a battery is highly dependant on it’s surrounding temperature. With it’s high quality design, the Growatt GBLI6532 can withstand a wide temperature range of between -10°C and 50°C. This is important for the battery to maintain it’s efficiency, as a stable temperature control ensures that the battery cells are protected during a charging and discharging cycle.

94.5% Depth of Discharge

Depth of Discharge (DoD) is the percentage of the battery that has been discharged relative to it’s overall capacity.  This is an important factor because there’s a correlation between the DoD and the cycle life of the battery.  The higher the DoD implies you can use more of the energy stored in the battery.  The more often you charge and discharge a battery, the shorter it’s lifespan will be.  It’s not good practice to discharge a battery fully as that shortens it’s lifespan, with manufacturers advising on a maximum recommended Dod. The DoD of the Growatt GBLI6531 is 94.5%. However, the DoD of the GBLI6532 isn’t shown, but we can safely assume it would be at least this percentage being a newer model.  This means a greater percentage of the batteries capacity is usable than most of Growatt’s competitors such as  Sonnen (90% DoD and Alpha ESS (90% DoD).

Compact Size and Easy Installation

With dimensions of 475*745*149 (width, height & depth), the Growatt GBLI6532 is designed for easy installation as part of your solar PV system for homes large or small. The ease of installation ensures that even novices who are attempting to retrofit their batteries to an existing system won’t get into too much trouble.

How much do Growatt batteries cost?

See the below table which provides an indicative guide based on data from Solar Choice’s Battery Price Index on the cost of installing a Growatt GBLI6532 with different battery capacity:

Please note

• Prices are recommended wholesalers listed price and including back up box – final price a customer would be quoted depend on the installer’s mark up and installation costs
• Price estimates does not include any state-based incentives

To give this cost context it is important to balance the cost of a battery against the return of a cheaper power bill. Solar Choice’s solar and battery calculator is a comprehensive tool to understand the financial viability – although be warned, we looked at 48 scenarios and couldn’t find anything that made financial sense.

Australian warranty terms for Growatt GBLI6532 battery

As per their warranty claim documents, the battery will end its warranty after a period of 10 years.

The time period of the warranty states that the warranty is valid from the date of customer purchase, and no more than 10.5 years from the date of delivery from Growatt. The extra 0.5 years is appropriated for the product to be in stock with the installer or distributor. If Growatt delivers to the installer and they don’t sell it for a year – effectively that would mean that the customer would only get 9.5 years warranty. We have confirmed with Growatt that whilst this may be true in theory, in practise most distributors typically wouldn’t hold their batteries for one year, with most being installed in three months.

It’s worth mentioning that the capacity of the battery is to be under 60% of the Nominal Operation Energy (nameplate value) within 10 years from the date of warrantied period when making a claim. If the battery capacity drops below 60% of its Nominal Operational Energy within 10 years then the customer can make a claim. So for example, if in year 9 a customer only has 2.5kWh of battery capacity from their 5kWh battery then they could make a claim with Growatt.

There are a few interesting provisos to the warranty being performed, namely:

• It’s stated in the document that the battery is intended to only be used with “Growatt Storage Devices” which includes the Growatt SPA, SPH Series and SPF series.  We have confirmed with Growatt that they intend for the user to only use this battery with a Growatt inverter.
• Outdoor installation and usage. This exception is unusual because of the fact that the battery is rated IP55 which is designed for outdoor use. We have confirmed with Growatt that  there must be some shade to cover the batteries and there can not be any direct sunshine or rainfall on the battery.

As with their solar inverter modules, warranty can be claimed through their Australian office based in Silverwater, NSW which can be reached on 1800 476 928 (1800GROWATT) or email australia@ginverter.com

Review Growatt’s warranty document here.

GBLI6532 specifications

Read about home battery government schemes across Australia

South Australia, New South Wales, Victoria, and Australian Capital Territory all currently have a home battery scheme in place.

The South Australian Home Battery Scheme enables eligible South Australian residents to receive up to $4,000 per installed battery.

The New South Wales Home Battery Scheme offers an interest-free loan up to $9000 for eligible households looking to install a solar battery.

The Victorian Government under the Solar Homes Program provides to those eligible, a maximum discount of $4,174 off the battery sale price. The next release of battery rebates is on the 2^nd of September 2020.

The Australian Capital Territory Government under the Next Generation Energy Storage program provides a rebate of $825 per kilowatt (kW). An average household with a 5kW system would be eligible for approximately $4,000.

Read more product reviews from Solar Choice