I'm traveling with my Apple Powerbook - but everyone's power supplies are pretty much the same and this doesn't involve software (much).

At home I use the AC adapter that came with the computer. No problems.

On the road I take a Kensington adapter because it also works on planes. It kept the computer running fine but wouldn't charge it. I ran the battery down to about 40 percent in the JFK gate area when my flight was delayed by a few hours but didn't worry about it because I knew there would be power on the plane and I could always finish recharging at my destination.

For the next two days it didn't recharge. The charge dropped by a percent or so every time I shut it off and turned it on again. Two days into the trip, despite the computer being plugged in whenever it was in use, the charge was down to about 30 percent. Not a problem, but I didn't like the trend.

I was all set to head to Lucky Plaza on Orchard Road (I'm in Singapore at the moment) to find a new adapter when I decided to call my GF first. While on Skype I noticed that the charge had gone to 32 percent. It's up to 57 percent now and climbing well - up 3 percent since I started writing this post. Some store there just lost a small sale.

I did not do anything to any of the connections. Had any been bad, it would have discharged at the usual rate for operating off the battery. Instead, I could leave it on for a day with zero to 1 percent battery level drop.

Can anyone suggest what might have caused this odd behavior in the first place and what made it reverse itself and start working correctly later?

(Actually, there is one Apple-specific bit: while the charge was holding/declining, the battery icon in the menu bar showed a plug; now that it's charging properly, it shows a sine wave.)