Selecting The Best Battery
When selecting the best battery for your needs, you should consider
Battery size
The battery size is the storage capacity of the battery. Smaller batteries are suitable for smaller solar panel arrays, likewise, larger arrays are better suited to larger batteries. There is no point pairing a Duracell Energy Bank 2 with a 3kW system.
Reliability of batteries
Any reliability issues should be factored into your selection of a battery.
Cycle life
The cycle life figure represents how many times the solar battery can charge and discharge before the battery is no longer usable. For most batteries, the cycle life is around 4,000 cycles which allows for daily charging and discharging over a 10-year period.
Warranty
Most solar battery warranties are valid for 10 years. The warranties typically correlate with the number of cycles. Though warranties are a ranking factor, it is worth considering that currently no lithium-ion battery has been installed for 10 years or more in Australia.
Functionality
You need assess whether or not the battery can be configured to do what you want it to do. If you need backup power, not every battery can provide it.
Value for money
We prefer to use value as opposed to price as a ranking factor. If a battery is twice as dear but lasts three times as long, it is better value. Value is subjective too, it’s very much on you as the buyer, to determine what is value in your own eyes.
Australian presence
An Australian presence for the battery manufacturer is important in case something goes wrong. It’s far easier to speak to Australian representatives than it is a consultant overseas. A local presence also demonstrates the manufacturer’s commitment to the Australian battery market.
The Best Solar Batteries
Solar batteries come in different sizes. Some batteries are suitable for small systems while larger solar panels arrays will be better paired with a larger battery.
The tables below show the best quality batteries according to their size:
Best Small Batteries (5KWH and under)
| Brand: | Size: | Reliability: | Cycle life: | Warranty: | Value: |
|---|---|---|---|---|---|
| Sungrow | 5 kWh | Good | 6,000 cycles | 10 Years | Very good |
| Enphase | 1.2 kWh | Good | 3,650 cycles | 10 Years | Good |
The three best batteries for small solar power systems are:
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Sungrow battery
The Sungrow battery is a well-priced small to medium size battery. At 4.8kWh, the battery is large enough to service smaller panel arrays. So far, the Sungrow battery has performed well during reliability testing.
-
Enphase battery
The Enphase battery comes in 1.2kWh units that can be added to at any point in time. The Enphase solar battery is an AC battery capable of being fitted to any system. One downside to the batteries is that they do not have backup power functionality.
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Sofar battery
The Sofar battery is a VERY cheap small to medium size battery. At 5.2kWh, the battery is large enough to service smaller panel arrays. So far, the Sofar battery has performed well during reliability testing.
Best Solar Batteries (over 5KWH)
| Brand: | Size: | Reliability: | Cycle life: | Warranty: | Value: |
|---|---|---|---|---|---|
| Duracell | 9.6 kWh | Good | 6,000 cycles | 10 Years | Very good |
| LG Chem | 10 kWh | Good | 4,000 cycles | 10 Years | Good |
The two best battery storage options for larger household grid-connect systems are:
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Duracell Energy Bank 2
The Duracell Energy Bank 2 can be fitted to any grid-connect system. It is reasonably priced and represents reasonable value for money and has performed well during recent testing.
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LG Chem Resu
The LG Chem battery is one of the most popular in Australia. You can take some comfort in the fact that LG have a large and vested interest in the solar market with their quality panels, and now batteries.
Both the LG Chem and Duracell Energy Bank II batteries are a good battery size for a 5kW system.
Solar Battery Prices
Adding solar battery storage to your system will allow you to save extra dollars, but it will come at a price. Solar batteries are relatively expensive, and the payback period is longer than for solar panels.
It is more economical to include solar battery storage as part of a new solar power system as opposed to adding a battery to an existing system. The table below shows typical solar battery prices for new systems, and adding to existing systems.
Battery Prices For New And Existing Systems:
| 5 kWh battery | 6.4 kWh | 10 kWh | 14 kWh | |
|---|---|---|---|---|
| New system: | $5,500 | $6,800 | $10,000 | $14,000 |
| Adding to existing:* | $7,700 | $9,000 | $12,500 | $15,700 |
*Assumes a new hybrid inverter is needed to install the battery.
The average cost of batteries
The table shows that the average cost of solar batteries is around $1,000 / kWh. This figure can be used as a rough guide; if you want a 10kWh with a new system, expect to add around $10,000 to the cost of the solar panels.
Hybrid inverter add-on
If you already own solar panels, and are wanting to add a battery, you may need to pay for an additional inverter and charger. If you purchased a battery ready system, you will likely avoid this additional cost, provided the battery you select is compatible with your hybrid inverter.
The cost of a hybrid inverter and charger varies depending on the size of the battery you need, but typically adds over $2,000 to the cost of the install.
Solar battery price variables
There are several variables that will affect the price you ultimately pay for a solar battery. The size, brand and quality of the battery you choose will have a big bearing on the price, as will any add-ons you may opt for. Battery price variables include:
- Applicable solar battery rebates
- Added functionality eg. Backup power
- If your existing system is compatible
- Battery brand
- Battery size
Battery rebate schemes
The solar battery prices and payback periods we refer to above do not include any battery rebates. There are state-based rebate schemes that can significantly decrease the cost of solar batteries and in turn shorten the payback period.
Payback Periods And Savings
Typically, a panel and battery system will payback somewhere between 5 – 7 years. If you already own solar panels and are just adding a battery, the payback is far greater, more like 7 – 10 years.
To assess the viability of battery storage, we will compare the results for a 6.6kW system with a 10kWh battery in Brisbane– with no battery, buying a panel and battery together and adding a battery to an existing system:
Solar Battery Financial Results For A 10 KWH Battery
| Cost | Annual savings | Payback period | Longevity | |
|---|---|---|---|---|
| Panels only: | $5,650 | $1,601 | 3 Years | 25 years |
| Hybrid system: | $14,150 | $2,243 | 6 Years | 10 years |
| Battery only: | $10,500 | $642 | 16 Years | 10 years |
*Figures based on electricity bills of $450 per quarter.
Are Solar Batteries Worth It?
YES, all of the latest articles are based off OLD pricing from 2017 when batteries were 3x the price and not financially viable. The prices have dropped significantly and are 100% now a better option than getting money back on a feed in tariff especially when you can purchase them factory direct from South East Solar & Maintenance.