Half of iPhone users have noticed a boost in their battery life after upgrading to the iOS 5.1 software, a poll conducted by the Cult of Mac stated Wednesday.

Some 6,000 people voted in the poll and just under 50 percent said they noticed an improvement to the battery performance on their iPhone. Some 13 percent said the battery lasted twice as much and another 20 percent said it was better than the iOS 5.01 software.

Some people are still not happy with their battery performance. About 17 percent in the poll said there was some improvement but it still isn't good enough.

When Apple released its iPhone 4S with iOS 5 software in October, one of the biggest shortcomings was battery drain.

Many iPhone and iPad users flocked to online Apple forums complaining about serious battery drainage, even when prime features, such as Siri, were not being used.

After admitting that the iOS 5 software had a battery bug, Apple quickly released an iOS 5.01 update, which purported to fix the problem, but many iPhone and iPad customers were dissatisfied with the performance.

Apple hasn't introduced any more solutions to its battery problem in the past five months, but with the release of the new iPad last Wednesday, came the new iOS 5.1 software that again claims to boost battery life.

A glance at online Apple communities indicates that most people have noticed an improvement in battery life, but there are mixed reactions, with some saying the battery drainage is worse that it was with the 5.01 software.

With the new iPad coming out on Friday, many Apple users are waiting to see how the software will perform on the tablet's specified 10-hour battery life.