If you have multiple batteries for your (post-1997) Apple laptop and prefer not to tote around multiple power adapters then Fastmac may have a solution for you. The U-Charge is a lightweight, cost effective, and compact charger for iBooks, PowerBooks, MacBooks and MacBook Pros, with a nice little bonus feature: it can charge a battery without the help of a laptop. No more swapping batteries just to keep them all juiced up!
The U-Charge connects directly to your MacBook battery’s terminals and thus needs to be put on a level surface to ensure proper contact. It’s only a 45W, so those with MBPs will have to wait a few hours to power up your secondary battery. I ran into some unwanted downtime when I chose not to bring my power brick. LEDs on the U-Charge mimic the battery level indicators on the Apple batteries themselves, so you can gauge how far along the battery is at any time.
While the U-Charge is a great addition to any MacBook owner, I have my issues with the device. The connecting terminal is really fragile (not material-wise) and you have to have the battery and U-Charge on a level surface so the contacts are properly aligned. They cannot make a connection at a 90-degree angle because it will reverse polarities rendering both your battery and U-Charge useless. Be sure that you read the instructions or inform whomever you purchase this for to do so. But it’s something you live with and get used to. I have at least.
Fastmac’s U-Charge is worth the $80 price tag, which I don’t really think is all that high considering its usefulness. It’s a great alternative to carrying the heavy MB adapters if you don’t mind waiting or if you have an extra battery. There are 10.8V and 14.4V models, so make sure you get the right one.