The bulk of the complaints were upheld with guilty verdicts.
It is a similar situation in the 2nd and 3rd Combat Support Services battalions.
Overall, the punishments varied, but included detention, confinement to barracks, reduction in rank, and in some cases a fine.
One instance included a private found guilty of assaulting a civilian. That resulted in a discharge without conviction, $1200 reparation and three months formal written warning.
Three out of the seven battalions had no reported complaints over the past two years.
Valerie Morse from Peace Action Wellington said the incidents of common assault are not surprising.
"I don't think it is just a matter of a few bad eggs - I think there is the wider culture of military discipline and military command that has to be understood and the way in which a military can condition people to do the very job that it has to do," she said.
The OIA said allegations of bullying or harassment can be made to doctors, psychologists, social workers, sexual assault advisers, or military chaplain and these may be kept confidential.
The Defence Force said that may mean these cases of abuse do not get recorded in the official figures.
An independent report released this year was critical of the progress made with the military's culture change programme, Operation Respect, which was launched in 2016 to address sexual violence, harassment and bullying.
Forty-four recommendations were made - including establishing an independent Defence Ombudsman to receive and process complaints.
In a statement, the Defence Force said it takes all allegations and complaints seriously.
"Complaints are managed sensitively and support and advice is provided to all parties. This support is offered through Defence Human Resources and other channels such as social workers, chaplains and anti-harassment advisors.
"The New Zealand Army does not tolerate violence within its ranks. Such behaviour is not in line with our values of Tū Kaha, courage, Tū Tika, commitment, Tū Tira, comradeship and Tū Māia, integrity. Where we see such behaviour we take action."
But blending the fighting role of the military with an appropriate culture is seen as a difficult task.
A lecturer in defence and security studies at Massey University, Terry Johanson, said soldiers were being asked to prepare for conflict and then also conduct themselves like ordinary people.
"For me it tends to be the type of training they're doing and then being able to bring these people down from that sort of hyper-aggressive state back to sort of normal society - because as you can understand if they're training for combat - that doesn't resemble what society is like."
He said further analysis would have to be done to paint a more complete picture of why these assaults were happening.
