We are always on them but can your smartphone assist your evidence in a Family Court case? And can you record your partner in a family law dispute without their consent?
In NSW the recording of a private conversation to which a person a party is prohibited pursuant to Surveillance Devices Act 2007 (NSW). However, a recording can be deemed admissible where the recording was reasonably necessary for the protection of the lawful interests of that party. 
The Court may exercise its discretion to admit the evidence under the Evidence Act 1995 (Cth). That legislation states that evidence which is improperly obtained or is in contravention of Australian law is not admitted unless the desirability of admitting that evidence outweighs the undesirability of admitting evidence that has been obtained in the way which evidence was obtained.  Secondly, the Court may refuse to admit evidence if its probative value is substantially outweighed by the danger that the evidence might be unfairly prejudicial to a party, or misleading or confusing or cause or result in undue waste of time. 
Recent case law has assessed the issue on a case by case basis.
In the case of Huffman v Gorman (No 2)  FamCA 1077 the Court considered whether to allow a recording into evidence despite it being illegally obtained. By way of background, the dispute was in relation to parenting. The father alleged that the mother was violent throughout their relationship. The mother denied his allegations on the basis that the father never reported his concerns to the police. During the proceedings, the father produced a number of recordings of the mother during the relationship. In coming to his conclusion Judge Harman noted the notorious difficulty to obtain evidence of family violence, which often takes place behind the closed doors and allowed the evidence on the basis that the best interests of the children are paramount and outweighed the undesirability of admitting evidence which was unlawfully obtained. 
In the recent case of Coulter v Coulter (No 2)  FCCA 1290 the mother secretly recorded the father’s attendance during the change-over at her home and secretly obtained two audio recordings between him and the children. The Court found that it was not improper for the mother to video record at the changeovers as she had a legitimate concern for her safety and the Court was satisfied in her evidence that at the time she was having ongoing difficulties with the father. However, the Court did find that the private recordings of the father’s conversations with the children was a breach of privacy and the audio conversations with the children were excluded from evidence. 
It seems that in cases where family violence is alleged, the Family Court is becoming more open to exercising its discretion to allow evidence to be admitted which might otherwise not be permitted.
 Surveillance Devices Act 2007 (NSW) s7.
 Surveillance Devices Act 2007 (NSW) s 7 (3)(b).
 Evidence Act 1995 (Cth) s 138.
 Evidence Act 1995 (Cth) s 135.
 Huffman v Gorman (No 2) FamCA 1077 
 Coulter v Coulter (No 2)  FCCA 1290 -