BLOG / 2015 - January

Understanding Batteries

For some households a battery system can be of great benefit and minimise a home’s reliance on the grid. However, it’s important to understand for a battery to be useful your solar system needs to be generating excess energy for the battery to store, which you can then use at night or when the sun is not out.

When selecting a battery, you’ll want to invest in a system that is most suited to your home and can drive the best return on investment (ROI). Despite a larger upfront cost, a higher quality battery may significantly increase your ROI.

Battery systems start from $6,000 and costs can vary greatly based on the following factors:

1. Cycle Life-Time

   The number of times a battery can fully charge and discharge.

2. Battery Power (kW)

   How fast it can be charged or discharged.

3. Storage Capacity (kWh)

   The maximum amount of energy a battery system can store.

4. Battery Management System (BMS)

   An electronic ‘smart’ system that gathers data and manages the battery ensuring it does not overload or operate outside of its safe functioning zone..

5. Inverter

   Battery systems require their own inverter if your solar system does not have a hybrid inverter.

6. 'All-In-One Unit’

   A system which includes the battery, BMS and an inverter all in one unit.

7. Warranty

   Length of time or cycles the battery system is under guarantee.

8. Blackout Protection/Backup

   It’s important to note this is not a common feature of a battery system and could cost thousands of dollars to include. Blackout protection not only requires additional components but also a specialised installation and rewiring. For grid-connected homes, the cost for blackout protection can outweigh the benefit.

Additionally, if your purpose for adding battery is to go Off-Grid and become completely independent from the grid you will need to ensure your solar system can generate enough energy to power your home and your battery system is large enough to store this energy. For homes in metro areas going Off-grid is not cost effective and is only recommended for those in remote areas with limited access to the grid. Off-grid solar systems with battery start at approximately $30,000.