Battery Review - Energy storage systems
Most modern battery systems used for homes or businesses are made up of lithium battery cells housed in a compact enclosure together with a battery management system (BMS). These battery systems such as the LG chem RESU series work in conjunction with a compatible hybrid or off-grid battery inverter.
In the past the well known lead-acid (Gel or AGM) batteries were the only option available but this review will focus on the newer lithium batteries, plus some unique Redox flow and ultra capacitor based batteries. Until recently almost all batteries were DC or AC coupled, although 'AC batteries' such as the Tesla Powerwall 2 and Sonnen ECO are now becoming popular. AC batteries are essentially a lithium battery unit combined with an integrated battery inverter/charger and smart control systems.
Modern lithium battery systems are housed in a sealed battery enclosure containing multiple sensors and battery management systems (BMS) which is essential to monitor battery voltage, state of charge and cell temperature (thermal monitoring). The 'managed' DC lithium battery systems must be coupled with a compatible solar hybrid or Interactive Inverter to operate and deliver AC power to the loads.
Battery Evolution
A good example of the rapid changes happening in the battery world is highlighted in the evolution of the Tesla Powerwall. The first generation 6.4kWh Powerwall (no longer available) was a high voltage DC-coupled battery which was installed together with a compatible hybrid inverter. The second generation Powerwall 2 released mid 2017 was an AC battery with integrated inverter at double the capacity (13.5kWh) and close to the same price. Another example is the LG chem RESU range of batteries which were only available in one size and are now offered in three sizes and two voltage options.
LG Chem RESU
Extra Low Voltage Residential unit - 48V DC
LG Chem Ltd often referred to as LG Chemical is headquartered in Seoul, South Korea and was the 13th largest chemical company in the world by sales in 2014. LG Chem completed development and began mass production of Korea’s first lithium-ion batteries back in 1999. LG Chem is the world’s third-largest maker with an annual production capacity of 1,000 million cells and is also a supplier of automotive battery for electric vehicles such as the Chevrolet Volt and Ford Focus electric.
See the full LG Chem battery review article here
Basic specifications: (3 battery sizes available)
Type: Battery system - Lithium NMC - 48V battery ELV
Use: Self-use, back-up, Off-grid (when used with an appropriate inverter)
Power output: 4.0kW (4.2kW peak) for 6.5kWh module
Battery System Voltage: 48V (51.8V)
Battery type: Lithium NMC (lithium-nickel-manganese-cobalt)
Battery size - 48V: 3.3kWh, 6.5kWh, 9.8kWh
Usable capacity: 90%
Features:
Compact, lightweight battery module with integrated BMS.
High surge/peak power output.
Expandable with up to 19.6kWh (with LG adapter)
Claimed 3000 cycles at 80% DOD (to EOL 70% capacity)
Compatible with a wide range of hybrid and off-grid inverters - Goodwe, Redback, Selectronic, SMA Sunny island, Schneider, Solax X hybrid, Victron Energy and many more.
Note:
No DC to AC inverter included.
Derates output in high ambient temperatures above 40 degC.
Warranty - 10 years
Price – LV 9.8kWh = AU$7800 ($740 per kWh)
LG Chem RESU-H
High Voltage Residential unit - 400V DC
LG Chem Ltd often referred to as LG Chemical is headquartered in Seoul, South Korea and was the 13th largest chemical company in the world by sales in 2014. LG Chem completed development and began mass production of Korea’s first lithium-ion batteries back in 1999. LG Chem is the world’s third-largest maker with an annual production capacity of 1,000 million cells and is also a supplier of automotive battery for electric vehicles such as the Chevrolet Volt and Ford Focus electric.
See the full LG Chem battery review article here
Basic specifications: (2 battery sizes available)
Type: Battery system - Lithium NMC Higher Voltage DC battery
Use: Self-use, back-up (UPS)
Power output: 3.5kW, 5.0kW for 10kWh module
Battery System Voltage: 350-550V DC (400V nominal)
Battery type: Lithium NMC (lithium-nickel-manganese-cobalt)
Battery size - 7.0kWh and 9.8kWh total capacity
Usable capacity: 90% - 6.6kWh and 9.3kWh
Features:
Compact, lightweight battery module with integrated BMS.
High surge/peak power output.
Low voltage 48V and High Voltage 400V options
Claimed 3000 cycles at 80% DOD (to EOL 70% capacity)
Wide range of compatible inverteres
Note:
No DC to AC inverter included.
Range of compatible hybrid inverters: SMA Sunny boy storage, SolarEdge StorEdge hybrid.
Derates output in high ambient temperatures above 40 degC.
Warranty - 10 years
Price – HV 9.8kWh = AU$8400 ($760 per kWh)
Tesla Powerwall 2
Tesla is an innovative company based California, USA specialising in electric vehicles such as the model S and advanced lithium battery technology. Headed by the well known entrepreneur Elon Musk, Tesla is now known as a world leader in energy storage tehnology and is constructing the worlds largest battery manufacturing facility known as the Gigafactory which is predicted to reduce the cost of lithium-ion storage batteries by up to 30% once fully operational in 2018.
Basic specifications: (1 battery size available)
Type: AC Battery system - Lithium NMC
Use: Self-use, back-up (UPS)
Power output: 5kW (7kW peak)
Battery System Voltage: 350-450V DC
Battery type & size: Lithium - NMC (nickel-manganese-cobalt) 13.2kWh
Usable capacity: 90% - 13.5kWh of total 15kWh capacity (estimated)
Features:
Integrated AC-DC converter.
Outdoor weather rated (IP66).
Only battery available with liquid thermal cooling.
Compatible with a wide range of systems (AC coupled)
Note:
DC model no longer available
Up to 9 units to be connected in parallel
Not designed for off-grid installations
Warranty - 10 years
Price – AU$10500 ($890 per kWh)
Pylon Technologies US2000B
Shanghai Pylon Technologies Co., Ltd. is the leading Chinese supplier and manufacturer of Lithium LiFePO Cell batteries. Producing a large range of battery systems including high Energy LiFePO Cells, Telecom Backup Lithium Battery, Lithium UPS Battery, Car Starter Battery and Electric Vehicle Lithium Batteries.
Basic specifications: (1 battery size available)
Type: Battery system - Lithium LFP
Use: Self-use, back-up (UPS)
Power output: 2kW (2.2kW peak)
Battery System Voltage: 48V
Battery type & size: Lithium Iron Phosphate (LiFePO4)- 2.4kWh
Usable capacity: 80% - 1.92kWh
Features:
Compact battery module with integrated charger & BMS.
High surge/peak power output.
Expandable with up to 4 x 2.4kWh units
Claimed 4000 cycles at 60% DOD (to EOL 80% capacity)
Compatible with Goodwe, Redback, SMA Sunny island, Solax X
Note:
No DC to AC inverter included.
Low surge/peak power output.
Warranty - 5 years
Price – AU$1600 ($660 per kWh)
PowerPlus Energy
PowerPlus Energy is an Australian based manufacturer supplying high performance modular self-managed lithium Iron Phosphate batteries to the Australian market. The batteries available in rack mount modules are easily scalable and 'self-managed' so do not require communications to the inverter like many lithium battery systems, thus can also be used as a drop-in replacement for lead-acid battery systems.
Basic specifications: (2 battery sizes available)
Type: Battery system - Lithium LFP
Use: Self-use, Off-grid (when used with an appropriate inverter)
Power output: 3kW (continuous & peak)
Battery System Voltage: 24V, 48V, 120V
Battery type & size: Lithium LFP - 3.3kWh & 4.0kWh (ECO)
Usable capacity: 100% (refer to warranty details)
Features:
Attractive battery module with integrated charger.
Expandable up to MW scale
Compatible with most off-grid and hybrid inverters
Note:
Relatively low cycle life (2000 cycles)
Two sizes available - 3.3kWh, 4.0kWh ECO only available in 48V
Warranty - 10 years
*Price – AU$2900 ($850 per kWh)
BYD B-Box
Extra Low Voltage Residential unit - 48V DC
BYD Co is a leading Chinease vehicle and lithium battery manufacturer which began operations in 1995. Initially focusing on electric vehicles and mobile phone batteries BYD has recently entered the competitive home energy storage market.
Basic specifications:
Type: Battery system: Lithium LFP - DC battery system
Size - Capacity: 2.5kWh modular (up to 10kWh), 12.8kWh
Use: Self-use, Off-grid (when used with an appropriate inverter)
Power output: 2.5kW per module (continuous & peak)
Battery System Voltage: 48V
Battery type: Lithium LFP (Lithium Iron Phosphate)
Usable capacity: 95% - 2.4kWh per module
Features:
Modular battery system with 2.5kWh units.
Compatible with common hyrbid battery 48V inverters
Compatible with many hybrid inverters including: Selectronic, SMA, Goodwe, Solax, Victron.
Can have up to 8 units in parallel
Warranty 10 years
Note:
No DC to AC inverter included.
Wide operating temperature range (-10 to 50 degC)
Can be installed outdoors (IP55 rated)
Price bracket – TBA
See full specifications and data sheet HERE
BYD B-Box HV
High Voltage Residential unit - 200-500V DC
BYD Co is a leading Chinease vehicle and lithium battery manufacturer which began operations in 1995. Initially focusing on electric vehicles and mobile phone batteries BYD has recently entered the competitive home energy storage market.
Basic specifications:
Type: Battery system: Lithium LFP - HV DC battery system
Size - Capacity: 1.12kWh modular (up to 10kWh)
Use: Self-use, Backup (UPS)
Power output: 1.1kW per module (continuous), Peak = 2kW
Battery System Voltage: 200-500V DC
Battery type: Lithium LFP (Lithium Iron Phosphate)
Usable capacity: 95% - 1.05kWh per module (9.5kWh for 9 modules)
Features:
Modular battery system with 1.12kWh units.
Compatible with HV hybrid inverters including: SMA Sunny boy storage, SolarEdge StorEdge hybrid.
Can have up to 5 systems in parallel
Warranty 10 years
Note:
No DC to AC inverter included.
To be installed in protected location (IP55 rated)
Price bracket – TBA
See full specifications and data sheet HERE
Simpliphi PHI
Simpliphi previously known as LibertyPak is US based battery manufacturer which has been a leading developer of Lithium based batteries since 2002. Initially developed for durable remote and mobile power systems the Simpliphi batteries are known for their high cycle life, safety and stability.
Basic specifications: (2 battery sizes available)
Type: Battery system - Lithium LFP
Size - Capacity: 2.6, 3.5kWh modular (up to 100kWh+)
Use: Self-use, Off-grid (when used with an appropriate inverter)
Power output: 1.7kW per module (continuous), Peak 3.0kW 10sec
Battery System Voltage: 24V, 48V
Battery type: Lithium LFP (Lithium Iron Phosphate)
Usable capacity: 100%
Features:
Modular battery system up to MWh scale
Compatible with common hybrid (24V or 48V) inverters
Very high cycle life (10,000+ claimed)
Safe, stable battery chemistry
Note:
No DC to AC inverter included.
Must be installed indoors (IP20 rated)
Warranty - 10 years
Price bracket – TBA
See full specifications and data sheet
GenZ LFP
GenZ is a small Australian battery manufacturer which assemble high quality imported LFP cells into the modular scalable battery units with integrated BMS. The units are 'self-managed' and do not require communications to the inverter like many lithium battery systems thus can also be used as a drop-in replacement for lead-acid battery systems.
Basic specifications: (2 battery sizes available)
Type: Battery system - Lithium LFP
Size - Capacity: 2.0, 3.0kWh modular (up to 100kWh+)
Use: Self-use, Off-grid (when used with an appropriate inverter)
Power output: 1.5kW per module (continuous & peak)
Battery System Voltage: 24V, 48V
Battery type: Lithium LFP (Lithium Iron Phosphate)
Usable capacity: 100%
Features:
Modular battery system up to MWh scale
Compatible with common hybrid or off-grid (24V or 48V) inverters
Very high cycle life (7,500+ claimed)
Safe, stable battery chemistry
Note:
No DC to AC inverter included.
Must be installed indoors (IP20 rated)
Warranty - 10 years
Price bracket – TBA
See full specifications and data sheet
SolarWatt MyReserve
SOLARWATT GmbH based in Germany was a well known solar panel manufacturer but restructured in 2012 to focus on energy solutions including battery storage systems. SolarWatt also created a partnership with BMW i to deliver high efficiency, large scale solar PV solutions.
Basic specifications: (1 size available)
Type: DC in-string battery system - Lithium-ion
Use: Self-use
Power output: 4kW (continuous & peak)
Battery System Voltage: 48V
Battery type & size: Lithium-ion - 2.2kWh (expandable up to 11kWh)
Usable capacity: 90% - 2kWh
Features:
Modular battery system with integrated inverter/charger.
High efficiency - 96.7% claimed
Expandable up to 11kWh
DC in-string system for easy add-on to existing systems
Compatible with most solar inverters (claimed)
Note:
Cycle life unknown
No back-up capability
Warranty - up to 10 years
*Price – $- TBA
Solax Battery
Suntellite Group headquarters is located in Zhejiang University with two major manufacturing plants in China, 14 laboratories and five engineering research and technology centers throughout China. Solax Power a subsidiary of the Suntellite Group manufacturers solar cells, panels, inverters, solar racking and LED lighting technology. Solax teamed up with LG chem to create the solax battery.
Basic specifications:
Type: Battery system - Lithium NMC
Size - Capacity: 3.3kWh, 6.5kWh (parallel up to 10 units)
Use: Self-use, back-up
Power output: 3.0kW per module (continuous & peak)
Battery System Voltage: 48V
Battery type: Lithium NMC (Nickel-Manganese-Cobalt)
Usable capacity: 95% claimed
Features:
Modular battery system with 3.3 or 6.5kWh (up to 10 units)
Compatible with common hyrbid battery 48V inverters
Optional forced air cooling
10 year warranty
Uses LG chem lithium NMC cells
Note:
No DC to AC inverter included.
Must be installed indoors (IP21 rated)
Price bracket – TBA
Ecoult Ultrabattery
Ecoult was formed in 2007 by the leading Australian scientific research organisation (CSIRO), but was acquired by the United States-based East Penn Manufacturing Company in 2010. The Ultrabattery is based on a unique long-life lead acid/ carbon capacitor technology and is lead based so is easily recyclable and environmentally sound. Ideal for larger commerical energy storage systems wih high demand plus well suited for remote microgrids.
Basic specifications: (Modular battery system)
Type: Battery system - Unique lead-acid capacitor combination
Use: Self-use, Off-grid, back-up
Power output: up to 20kW peak
Battery System Voltage: 48V
Battery type & size: Ultrabattery - 16.9kWh usable
Usable capacity: 90% - 25.4kWh
Features:
Unique lead-acid battery with carbon ultra capacitor
Very high power output -up to 20kW
Very good rapid charge and discharge
Individual battery unit monitoring
90% Depth of Discharge available for backup
Stackable up to MWh storage capacities
Safe, fire retartant system
Good temperature tolerance
Note:
No DC to AC inverter included.
High energy to weight ratio -up to 1,100 kg
More suited to larger commerical applications
Warranty - 10 years
Price bracket – $16500 = $1,650 per kWh
Aquion Energy AHI Battery
(Aquion filled for bankruptcy in early 2017 - Now Chinese owned)
Aquion Energy’s Aqueous Hybrid Ion (AHI™) battery systems are optimized for stationary, long duration daily cycling applications, including off-grid and microgrids, energy management, and grid-scale energy storage applications. The batteries utilize non-corrosive reactions at the anode and cathode to prevent deterioration of the materials. The water-based chemistry results in a nontoxic and non-combustible product that is safe to handle and environmentally friendly.
The batteries were problematic with poor performance due to the high internal resistance resulting in a large voltage drop under load. This caused many inverters to shutdown due to low voltage cut-off limits.
Basic specifications: (Modular battery system)
Type: Battery system - Sodium-ion
Use: Self-use (UPS when used with an appropriate inverter)
Power output: 8.1kW (9.7kW peak) - M100 series module
Battery System Voltage: 48V
Battery type & size: Each Individual S20 stack is 2.4kWh (The M100 module is made up of 12 x S20 stacks for total 25kWh)
Usable capacity: 100% - 2.4kWh (only over low 24hr discharge rate)
Features:
Battery module with integrated protection
100% Depth of Discharge available
Stackable up to MWh storage capacities
Non-toxic materials
Note:
No DC to AC inverter included.
High energy to weight ratio - 113kg per stack
Requires inverters with programmable charge voltage parameters which can operate in wide voltage window (40-60V)
May require additional battery management system to operate.
Cannot be used for high discharge or large surge loads.
Price bracket – TBA
Redflow Zcell (ZBM2)
Redflow, now an International company started in Australia has a new manufacturing facility (relocated) in China. The Zcell was one of the worlds first domestic flow battery systems (based on the previous version Redflow ZBM2 battery). The unique zinc bromide flow battery technology developed by the University of Queensland is capable of 100% discharge and can withstand partial or no charge for prolonged periods of time without degradation.
Basic specifications: (Modular battery system)
Type: Battery system - Zinc Bromide
Use: Self-use, Off-grid when used with an appropriate inverter
Power output: 3.0kW (5.0kW peak)
Battery System Voltage: 48V
Battery type & size: Zinc Bromide flow battery - 10kWh
Usable capacity: 100% - 10kWh
Features:
Unique flow battery system with integrated protection
100% Depth of Discharge available
Stackable up to MWh storage capacities
Safe, fire retartant system
High temperature tolerance
Note:
No DC to AC inverter included.
High energy to weight ratio - 240kg per unit
DC-DC conversion efficiency of 80%
Requires inverter with programmable charge voltage parameters which can operate in wide voltage window (40-60V)
Warranty - 10 years
Price bracket – $10,500 = $1,050 per kWh
Enphase AC Battery
Enphase Energy is a Californian company founded in 2008. Enphase is considered the world's leading manufacturer of solar micro-inverters and is well established in the US market. The recent release of the compact AC battery in mid 2016 is one of the first modular AC battery systems available.
Basic specifications: (Modular AC battery system)
Type: AC Battery system - Lithium-ion
Use: Solar self-use and off-peak charging only
Power output: 0.26kW per module
Battery System Voltage: N/A (AC battery)
Battery type & size: Lithium (LiFePO4) - 1.2kWh
Usable capacity: 95% - 1.14kWh
Features:
Attractive, compact, modular AC-battery
Integrated AC inverter
Can operate as a stand-alone unit (not back-up)
Stackable up to 13 units (15.6kWh)
Sophiticated monitoring system (with additional Envoy)
Very high cycle life (claimed 7,300 at 80% DOD)
Note:
No back-up power capability
Additional Enphase Envoy S unit required for setup and monitoring
Low power output per module - 260W
Low weather rating (IP20) must be installed indoors
Warranty - 10 years
Price bracket – $1550 = $1140 per kWh
Sonnen Sonnenbatterie ECO
Sonnen is successful German company founded in 2010. Previously known as Sonnenbatterie, Sonnon has become a leader in developing high quality, modular energy storage systems for residential and commercial applications.
Basic specifications: (Modular AC battery system)
Type: AC Battery system - Lithium LFP
Use: Solar self-use and emergency back-up power
Power output: 3.0kW (8.0kW peak)
Battery System Voltage: N/A (AC battery)
Battery type & size: Lithium LFP (LiFePO4) - 4kWh to 16kWh (2kWh modules)
Usable capacity: 100% (assumed capacity is 2.2kWh)
Features:
Attractive, modular system
Can operate as a stand-alone unit with some back-up support
Stackable up to 16kWh
Sophiticated monitoring system
Very high cycle life (claimed 10,000 cycles)
Note:
Relatively low inverter power output 3.0kW
Low weather rating (IP20) must be installed indoors
Back-up functionality limited
Warranty - 10 years
Price bracket – Approx AU$960 per kWh
Kilowatt Labs Sirius Super Capacitor
Kilowatt Labs is a US based company which designs and manufacturers energy storage and power management solutions including the worlds first super capacitor based modular energy storage system. See Kilowatt labs website
Basic specifications: (1 size available)
Type: Battery system - Super Capacitor
Size - Capacity: 3.55kWh modular (scalable)
Use: Self-use, back-up & Off-grid (when used with an appropriate inverter)
Power output: 5.3kW per module (continuous 110A)
Battery System Voltage: 48V
Battery type: Super Capacitor
Usable capacity: 100%
Features:
Modular super capacitor energy storage system
Very efficient - 99% round trip efficiency
Compatible with 48V hybrid/off-grid inverter/chargers
Extremely high cycle life - 1 million cycles (claimed)
Wide operating temperature range (-10 to 55 degC)
Safe, stable energy storage system
Low self discharge - 2 % per month
Can be stored at any State of charge without degradation
Note:
No DC to AC inverter included.
Max 54V charge voltage.
Series combiner required for connection of more than 3 modules
Cannot connect in parallel.
Must be installed indoors or in protected area.
Warranty - 10 years
Price bracket – $4500 + GST
See full specifications and data sheet
