The battery of my two-year-old 12” Albook is showing signs of serious wear.

Recently it was hovering at 57% charging capacity and was giving me about two-and-a-half hours of juice. Then in the space of two days that setting dived 12%, and I was getting an hour less Mac time on the road. Additionally, recharging the thing fully now took a whole day, as opposed to the usual couple of hours or so; it took forever to hit 100%, and I was getting erratic indication of how much power was left. The plug’s light ring would hardly turn green, and when it finally did (usually after an overnight charging), as I used it, it would turn orange and the indicator would drop to 97 or 98% - while being plugged in all the while.

Hmph.

Then again, it’s had 202 cycles already, and all things considered, it was about time. Maybe I’m asking too much of it. I’ve tried resetting the PRAM and the PMU, charged, drained and recharged the battery to condition it, all the usual stuff, and there’s been no change. I guess it’s on its last legs.

I had my friend (the one who went to Macworld and gave me a Belkin smartwrap) get me a Newertech enhanced battery in San Francisco, with a claimed 20% more battery life. I charged it for 12 straight hours overnight, as the included flyer said, and used it the whole day – amazingly it’s held up pretty well.

When I started using it this morning on batteries alone, it claimed 5 hours and 25 minutes, shifting back and forth from 4 hours, to 5, then to 3 and half and so forth. I used it to write three short articles, two posts, ran Bluetooth with Address Book so I could easy send text messages, and often tried to connect with the several wifi networks where I was. I did this on and off the whole afternoon, and it ran fine.

It finally warned me it was running on reserve power and said it was about to shut down at any time around 5 in the afternoon. The indicator said 6 minutes left. I continued using it. Then it said 4 minutes left, then 2, and soon hit 0%. I kept working, and it wouldn’t shut off until forty minutes later. Whoa. Forty minutes running on empty. Later that night, after its first recharge, the indicator said, tantalizingly, 6:22. I like this battery.

Batteries are important things, of course. Particularly for the mobile warrior. That’s why it disturbs me a great deal that Apple is apparently being deliberately vague about the battery behavior and characteristics of everyone’s new object of lust, the MacBook Pro. Even my friend who covered Macworld couldn’t get a straight answer from the Apple PR flacks.

Maybe when it ships we’ll have some word. If not from Apple, from the legions of early adopters who’d rather take the plunge now than wait for Revision B. Can’t wait.