By Sam Oliver

Published: 12:50 PM EST (09:50 AM PST)

Research in Motion's forthcoming PlayBook tablet is said to be "unlikely" to match the 10-plus-hour battery life of Apple's iPad, and could even struggle to meet the 6 hours of the Samsung Galaxy Tab without "significant engineering."

Analyst Shaw Wu with Kaufman Bros. said in a note to investors this week that his industry sources have indicated that RIM continues to experience major issues in developing its forthcoming PlayBook tablet, intended to take on Apple's iPad. He said he would be "very surprised" if the PlayBook manages to match the battery life of the iPad without using a larger battery.

Apple has an advantage over RIM, Wu said, because the iPad maker designs many of its own semiconductors, including the A4 processor that powers the iPad and iPhone 4. In addition, Apple makes its own battery chemistry, and software, allowing for power optimization that competitors like RIM cannot yet compete with.

Another potential problem noted by Wu is Adobe Flash, which he said could be a major factor in the battery life of the PlayBook. He noted that back in November, tests discovered that the new MacBook Air had its battery life significantly reduced when Adobe Flash was installed.

"It should be no surprise to anyone that our checks indicate Adobe is furiously working on reducing Flash's consumption of resources to make it a viable mobile platform vs. HTML5 that both Apple and Google are moving toward," he wrote.

Wu claims his sources indicated the "best" the PlayBook could hope for is to match the six hours of battery life offered by the Samsung Galaxy Tab, an Android-based device that launched last November. And even that would require "significant engineering," he said.

"The reason is that QNX wasn't originally designed for low-powered mobile environments but rather devices plugged into a wall socket (like networking equipment) or a car battery (like automobile control systems and stereos)," he wrote. "At the end of the day, we are glad RIM is working hard on improving battery life as it will be good for both customers and shareholders."

Wu's latest report is a follow-up to one he issued last week, in which he first revealed the alleged battery problems associated with the PlayBook. In that note to investors, he said the PlayBook gets just a "few hours" of uptime, faring worse than both the iPad and the Galaxy Tab.

RIM quickly shot back at Wu's rumors, and said its PlayBook would offer "superior performance with comparable battery life." The device is expected to launch in the first quarter of 2011.

"Any testing or observation of battery life to date by anyone outside of RIM would have been performed using pre-beta units that were built without power management implemented," RIM said in a statement. "RIM is on track with its schedule to optimize the BlackBerry PlayBook's battery life and looks forward to providing customers with a professional grade tablet that offers superior performance with comparable battery life."