FruitJuice can help you prolong your battery’s useful life. In this respect, the tool can monitor battery usage and recommend you when to plug or unplug your machine. It does so by tracking your battery for a first week to calculate how much you have used your computer. Then, the recommendation is to remain unplugged during 20 percent of that calculation.
The application runs from the Menu Bar, from where you can access its options. In this regard, the tiny icon there shows how much battery time is left in case your computer is unplugged at the time. Thus, you can consult your power usage as well as the factory capacity history. Likewise, it is possible to consult information about your battery. Similarly, you can view the recommended maintenance cycle, which is typically every 30 days.
As to notifications, it is allowed to configure those notifications you want to receive. This way, the application may alert you when the recommended battery time target is reached, the estimated remaining time falls below a given number of hours or the amount of remaining charge drops below a certain percentage. Likewise, while the battery is charging, it warns you when the amount of charge exceeds the desired percentage. Unfortunately, despite I can decide which notifications to be shown, I still feel they are too obtrusive.
All in all, FruitJuice works as described by its developer. It seems reasonable that it can help you preserve your battery in the long run. However, its price feels somewhat high if you take into consideration that there are similar applications for free.