J. D. Power and Associated has given the coveted Highest customer satisfaction rating to Apple’s iPhone for the seventh consecutive time.

Battery life tends to be the deciding factor in whether or not a customer is satisfied with their smartphone performance. It ranked highest in the reason people were satisfied with the top performing phones and the biggest reason why customers were unsatisfied with ones that performed poorly.

Satisfaction levels with battery performance differed widely between owners of 3G and 4G smartphones. Among owners of 4G-enabled smartphones, battery performance ratings average 6.1 on a 10-point scale–considerably lower than satisfaction among owners of 3G smartphones (6.7). Part of this difference stems from the fact that new 4G smartphones use substantial battery life searching for next-generation network signals. In addition, owners of 4G-enabled smartphones use their device more extensively than customers with 3G smartphones or traditional handsets–which puts a significantly higher demand on the battery.

“Both carriers and manufacturers recognize the fact that battery life needs to be improved,” said Kirk Parsons, senior director of wireless services at J.D. Power and Associates. “However, the study uncovers the need for a greater sense of urgency–short battery life can result in perceived phone problems, higher rates of merchandise returns and customer defections.”

When people find something that works for them, they stick with it. Approximately 25 percent of 4G-enabled smartphone owners are highly satisfied with their battery (ratings of 10 on a 10-point scale) and say they “definitely will” repurchase a device from the same manufacturer. In comparison, among owners who are less satisfied with their battery (ratings of 7-9 on a 10-point scale), only 13 percent say they will repurchase from the same manufacturer,

Additional Findings:

• The price of traditional headset cell phones declined an average of $66. 44% of customers got theirs for free.
• 70% use social networking sites on their phone.
• 21% experienced a software or device malfunction.

The study compares the satisfaction of 7,080 smartphone owners and 8,335 traditional mobile phone owners between July and December 2011.

Apple achieved a score of 839 on a 1,000-point scale and performed well in all factors, particularly in ease of operation and features. HTC (798) follows Apple in the smartphone rankings.

LG and Sanyo rank highest in overall customer satisfaction with traditional handsets, in a tie (716 each). LG performs well in all four factors, while Sanyo performs particularly well in ease of operation. Sony Ericsson (712) and Samsung (703) follow in the traditional handset rankings.