Battery backup systems are becoming popular for many reasons. They are ideal for low flow supplies from springs or bores or when friction is an issue due to undersized pipe or long distance. General solar pumping systems from most manufacturers/suppliers are rated at a pumping time of 6 hours. Solar Water Pumps Australia have angled panels to the NE and NW for many years to provide up to 10 hours or more pumping time. (sunrise to sunset). The next step for more water is to add batteries which can then provide up to 24 hours pumping time if needed.
In order to deal with a longer pump time situation, petrol/diesel units have been used to pick up where the solar leaves off. The benefits of a battery back up system are:
No fuel needed to run the pump
No need to travel to the site to start/stop the motor
No servicing of the motor, changing oil/fuel filters etc or labour
Overall running cost per head of livestock is far less over a 10 year period
Batteries are maintenance free
Calculations on some of the existing battery systems installed of late have shown that it ranges between .40 and .86 cents per sheep per year to install (dependent on various factors). If SA mains water is used the estimated cost per sheep can easily be $4-5 per head per year.