Upper Volta is an enhanced replacement for the macOS' built-in battery status indicator and supports the following functionality:

• Displays the percent of battery charge, the remaining time left on the current battery charge, or the time remaining until the battery is fully charged
• Toggle between a percent view of the battery charge or a time-based view using a user-defined global keyboard shortcut
• See whether the Mac is connected to a power adapter or running on battery
• See the number of battery cycles (charge cycles) used by your Mac’s battery
• See the condition and health of your battery (e.g., normal or needs servicing)
• Shows a battery indicator that adjusts dynamically based on whether your Mac is running on battery, is connected to a power source, is charging, or is fully charged; it will also provide visual indicators as the battery charge drains
• Choose to hide the battery indicator icon to free up menu bar space
• Choose to hide time-based status information to free up menu bar space
• Choose whether or not to run Upper Volta each time your Mac starts up
• Very lightweight and uses minimal system resources
• Runs on both macOS Catalina and Big Sur
• It’s free. Similar tools cost money!

Note: While the software is classified as free, it is actually donationware. Please consider making a donation to help support development.