The Arlo from Netgear is a 100% wire-free, HD smart home security camera which is easy to setup comes with apps for monitoring from your smartphone or tablet.
The camera / cameras will only start when something or someone crosses the “beam ” after you have turned motion detection on , from the camera and Netgear claim that the batteries can last up to 8 months.
These camera are also weatherproof and offer night vision so you can place them outside.
More details can be found on the Arlo Site and they can be purchased from leading retailers including Harvey Norman