The Powerwall 2 is a great product, its attractive for a battery, has a decent amount of storage and a well designed app. Being an AC coupled battery though, it has its pros and cons.
What’s an AC Coupled Battery? – Put simply, it means that the battery charges itself from AC power. It senses surplus solar power and absorbs it and then allows the surplus energy to be exported once the battery is full.
The up side of this is that it can be installed with any solar system. It doesn’t “talk” to your solar system at all so it doesn’t care what solar system you have.
On the down side, it has a 5kW inverter built-in which in Queensland counts towards your total inverter capacity allowance with Ergon and Energex. In Queensland, there is a limit of 10kW of Inverter capacity for single phase properties and because the Powerwall is 5kW, you will then be limited to a 5kW Solar inverter.
The sonnenBatterie is not just a battery, it’s an intelligent storage system that automatically adjusts the energy usage in your household. In combination with solar panels the sonnenBatterie will enable you to supply yourself with clean energy – thus making you independent and protecting you from energy price hikes.
Possibly its most impressive feature is its long life. The sonnenBatterie has a minimum lifespan of 10,000 charging-cycles. That’s over 2 per day. This is ideal to take advantage of Time of use or demand tariffs, so you can rest assured that it will supply you with clean energy for many years to come.
The sonnenBatterie exclusively uses lithium iron phosphate batteries – the safest lithium battery technology available today.
With its high cycle life, Sonnenbatterie is best suited to load shifting applications with a Time of Use tariff. Its also AC Coupled so it can go on any solar system.
The RESU range from LG Chem has become a popular choice of Hybrid systems and Off-Grid systems alike. With both Low Voltage and High Voltage models, they are compatible with virtually every battery inverter on the market. The RESU range is a Lithium battery with a Nickel Manganese Cobalt chemistry which gives it good specific energy (in other words, stored energy per Kg). Being a “managed” battery, it requires communication with its host inverter. RESU is available in 6, 10 & 13 Kwh models.
Sungrow PowCube 4.8
The newly released PowCube from Sungrow is a sleek and compact unit designed to work with the new Sungrow Hybrid Inverter. With similar styling, they are a great
match to each other.
The PowCube comes in the one size 4.8kWh and can be linked together up to 3 units to make a 14.4kWh bank.
PowCube uses the NMC chemistry that gives it the same great Specific Energy characteristic as the LG Chem RESU.
Power Plus Energy
Along with the Gen-Z (see below), these are our current favourite for Off-Grid systems. Australian made quality and being rack mounted they make a very neat, tidy and compact installation.
The PPE battery is an”unmanaged” lithium battery which means they have their own Battery Management System (BMS) on board and dont require communication with their host Inverter. The beauty of this is that each module manages itself, making it very safe and you can add extra batteries at any time. It also makes them essentially a Lead Acid replacement.
PPE batteries use the Lithium Iron Phosphate formula (LiFePo4) which is the safest lithium chemistry there is and they come is two variants.
- Premium LiFe Series 3.3kWh/module
- ECO Series 4.0kWh/module
Quick Comparison (*approx)
|MODEL||Price||Nom Cap kWh||Continuous
|PPE Life 48V||3.3||C2 32A||C1 63A|
|PPE ECO 48V||10% less*||4.015% more*||C2 39A||C2 39A|
It all gets a bit technical here but as you can see, because the ECO modules are limited to a C2 discharge, they can’t deliver all their energy as quickly as the LiFe modules. It makes them a great, value for money choice for some applications but unsuitable for others. Our Off-Grid Specialise will advise you on which model is best for you.
Very similar to the Power Plus, Gen-Z are manufactured by the Australian communications company Radlink. The Gen-Z modules have a casing made of 304 stainless steel with an industrial dip coating so its a good choice for coastal and Island jobs. Available in 2kWh and 3kWh and in 24V and 48v models.
For the mobile market, these Gen-Z N70 format batteries are great performers and very light weight. Built in BMS means they are a lead acid replacement. You can connect multiples in parallel for greater storage and they are available in 12v 100Ah and 24v 50Ah.
An excellent choice for boats, caravans and camper trailers as they weigh less than 14kg each.
For Offgrid use, where multiple days of autonomy is required, we use and recommend Sonnenschein tubular gel VRLA batteries. These German made cells are designed for use with
Solar and offer maintenance free service and high cyclic performance. Although an older technology, they are still an excellent choice for many Off-Grid and some Hybrid applications.
Super Capacitors are an emerging technology and promises to be a game changer for energy storage. Testing shows that they aren’t bothered by many of the issues related to traditional battery storage, including
- Operating temperature. – Its service life seems unaffected by extreme ambient temperatures.
- Cycle life. – The Sirius module pictured here offers 1,000,000 cycles.
- Charge and Discharge rates. – It can accept a wide range of charge & discharge currents.
- Fast charging. It can charge in a fraction of the time of Lithium or Lead Acid.
Climatecare Electrical has an extensive evaluation process for new products so it will be a while before we will be offering these, but keep an eye out for this product over the next few years.
If you want to learn more about Lithium Battery chemistries, click here.