While the portability of laptops is the main reason they’ve grown increasingly popular, that portability comes a price, namely rechargeable batteries. Not only do these batteries limit how long you can use the computer away from a power outlet, they gradually lose their ability to hold a charge.

That’s why laptop users need to be able to check the health of their computer’s battery periodically. True, you can always go to the Energy Saver System Preferences Pane and click on the “Show battery status in menu bar” option if you just want to know how much juice is left, but it’s helpful to know exactly how much of a charge your laptop battery can still hold, and how close it is to requiring replacement. Here are a few of the better options among the Mac battery freeware and shareware out there (all are Universal Binary, good for both PowerPC and Intel Macs):

CoconutBattery: Perhaps the most elegant of the freeware options, CoconutBattery offers a single gray window with three panes and lime green indicator bars. One pane shows the current battery charge and another current battery capacity, indicating how much of your original capacity your battery has lost since you’ve owned it. A bottom pane of “Additional Info” shows you “battery load cycles” (how many times you’ve recharged the battery) and the age of your Mac laptop in months. CoconutBattery even has a Dashboard Widget available.

Battery Health Monitor: Another freeware option, not quite as pretty as CoconutBattery, but gives you most of the same information. Battery Health Monitor has a grid at the top that shows you the power status of the laptop. When plugged in, the word “A/C Power” is bold for example; when on battery power, the word is grayed out. Other indicators include “Battery Depleted” and “Not Chargeable,” neither of which you’ll want to see bolded. Battery Health Monitor also tells you how many charge cycles the battery has gone through as well as the current voltage the battery is delivering.

SlimBatteryMonitor: This piece of freeware is essentially a fancy replacement for Apple’s battery icon. While it does not provide any of the supplemental data the other options do, SlimBatteryMonitor’s main attraction is that it takes up less space in the menu bar than Apple’s built-in version and is much more customizable, particularly in the colors you can choose for the battery icon.

iBatt2: I had the earlier version of this on my old G3 500 iBook, and it helped me track issues with two aging batteries. It’s $19 shareware, but does offer more than the other apps. iBatt2 offers multiple windows, some of which supply the same data as the freeware apps, such as current charge capacity versus the original capacity. A second window supplies the serial number and manufacture date of the battery, as well as “average time to full” data if you’re charging and “average time to empty” data if you’re on battery power. A third window uses data from other users stored online to compare your Mac laptop’s battery to others using the same model. In addition to the raw capacity numbers, iBatt2 assigns your laptop battery a grade. My MacBook’s battery earned only a “C.” The software also charts your battery’s power activities on a graph that updates itself automatically. Finally, iBatt2 has some cool-looking but not terribly useful gauges at the bottom of the screen showing wattage and charge levels.