The All Blacks endorsed Duracell in a television advertisement last year, provoking a complaint from rival manufacturer Energizer, which argued the ad went beyond endorsement by making an untruthful claim.
The ad showed the All Blacks during games, as well as a number of battery-powered devices including a stopwatch, radio and television remote.
A voiceover stated: "If you think any battery will do, consider the All Blacks. When they want to play at their best there is only one battery they trust, Duracell."
The ad then finished: "Duracell. Trusted everywhere."
Rival battery maker Energizer complained to the Advertising Standards Authority (ASA), arguing it was a conceptual overreach to claim there was only one battery the All Blacks trusted.
It argued the statement went beyond endorsement to the point of being untruthful and likely to deceive or mislead consumers.
Energizer also complained about the "trusted everywhere" line, claiming it went beyond hyperbole because it implied Duracell batteries had been widely available in New Zealand.
However, Duracell had been absent from the market between 2006 and 2013, and its batteries were available only from November 1 last year.
The ASA's complaints board did not uphold the complaint, noting a letter from the NZ Rugby Union that confirmed the endorsement and specifically approved the wording: "there is only one battery they [the All Blacks] trust".
The board also found the phrase "trusted everywhere" was not just a geographic claim, but a reference to the many appliances the batteries could be used in. Therefore, the claim was not misleading.
