What brand of batteries should you buy (or is Tesla your only choice)?
Solar battery storage has actually been around for a while. Lead acid batteries have been taking people totally off-grid for years - for a high price.
Though with the hype and fanfare around Tesla's announcement of its Powerwall battery you wouldn't really think this was the case!
A quick note on lead acid batteries
You'll notice that conventional lead acid batteries are not mentioned on this page. This is because I believe that lithium-ion, flow and salt water batteries are the future of residential household energy storage - they simply have longer guarantees than lead acid batteries and have a greater depth-of-discharge.
The one exception to this rule is a new type of lead acid developed at the CSIRO when I used to work there. It is called the Ecoult Ultra Battery, and uses a hybrid Ultra-capacitor/Lead Acid design to make a battery that lasts much longer and can discharge more power. At the moment, though, they only seem sell Ultrabattery products geared towards the larger commercial market.
Alternatives to the Powerwall
Our comprehensive, frequently updated Solar Battery Storage Comparison Table has all you need to know about what's currently on the market in Australia.