Laptop Battery Diagnostics Software?

• BatteryCare is a good tool.
• BatteryUniversity is a good source for information.

You may be able to use HP's Battery Check:

Not all models of this notebook series are supported. To determine if you model is support, download the HP Battery Check from the following address and install the Battery Check ( HP Battery Check (SP41862) File Download ). A message will be displayed if your system is not supported.

If not, check out Imtec Battery Mark:

• Produces test in two modes (fast and normal) with two variants of play on hardware load subsystem notebook: full load, or without it.
• At the time of testing construct a detailed schedule of changes in the level of battery power. After testing all the data stored in a log file for later viewing and / or analysis.
• The program fully supports multi-and multicore processors, which allows to reproduce the maximum possible load on the processor system to test a laptop in extreme conditions.
• After the testing, the total assessment system power notebooks, calculated by a unique algorithm, taking into account not only the time of the battery, and laptop performance during testing.

or BatteryMon:

• Graphically see the charge / discharge rate
• Diagnose problem battery cells with detailed statistics
• Compare and measure your batteries' performance with expected
  discharge rates
• See the critical discharge point for your batteries
• Uniquely identify battery packs for tracking purposes or system
  inventories
• Log the performance of a battery for later reference
• See the status of each individual battery pack, when multiple batteries are in use