Interesting findings are being reported in regard to Apple's new unibody MacBooks. Apparently, the new devices perform better while running on battery power, rather than on AC power. According to an Apple Support document, this is normal behavior, but Apple also recommends that users allow the battery to discharge at least once per month.

Tests carried out by the folks at Gearlog have revealed substantially lower performance while running on AC power alone (with the battery removed), in testing a unibody (Late 2008) MacBook Pro. The report notes a 36% lower processor benchmark without the battery. TUAW steps in and points out to two Apple Support documents that seem to be in conflict.

On the one hand, Apple shows that, “if the battery is removed from a MacBook or MacBook Pro, the computer will automatically reduce the processor speed. This prevents the computer from shutting down, if it demands more power than the A/C adaptor alone can provide,” the company explains.

On the other hand, Apple's Standard Maintenance of the Li-Ion MacBook battery says that "for proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally. Apple does not recommend leaving your portable plugged in all the time. An ideal use would be a commuter who uses her MacBook Pro on the train, then plugs it in at the office to charge. This keeps the battery juices flowing."

"If, on the other hand, you use a desktop computer at work, and save a notebook for infrequent travel, Apple recommends charging and discharging its battery at least once per month. Surely, not everyone has the time to be this attentive with their device. That's why Apple recommends that you add an event (reminder) to iCal."

Have you noticed the difference in performance when switching to AC alone? How about battery life – is the battery of your new MacBook holding out as advertised?