During the beta test, the FreedomPop Phone has been eating up battery exponentially. To remedy this battery issue, here are steps to have a long-lasting battery.

Step 1: Remove battery-intensive apps

Download App Quarantine from the Google Play Store.

Check the boxes for:

Android Live Wallpapers
App Sharing
Archive Viewer
Bookmark widget
Calculator widget
Calendar widget
Clock widget (only disable if you’re not using the clock on the home screen)
Connected Media
Facebook for HTC Sense
Friend Stream
GB_WeatherVideo_Base_40
HTC Hub
HTC Hub Widget
HTC Lock Screen
HTC Slide Show Wallpaper
HTC weather sync provider (only if you disable auto sync for weather)
HTC Weather Wallpaper
JETCET PRINT
JETCET PRINT Resources
Location Picker
Magic Smoke Wallpapers
Mail
Mail Widget
Maps (you can enable it again when you need to use it)
Media Share
Messages Widget
Messaging (only disable if you’re using Google Voice, GrooveIP, Talkatone, SparePhone, or you  barely call anyone)
Music
Music Enchancer
Music Visualization Wallpapers
News
News Widget
People (keep the android one, but disable the HTC one)
Picasa Web Albums
Ringtone Trimmer
Setup
Streak live wallpaper
Streaming Media Player (use MXPlayer from the Google Play store; it’s much better)
TalkBack (disable only if you don’t have a disability)
Task Widget
Tasks
Tell HTC
Transfer
TrimIt
Uninstall_LinkedIn_FSPlugin
Visual Voicemail (if you’re using the free service, you don’t need this hogging battery)
Voice Dialer (google already implemented one)
Weather (this is the com.htc.android.WeatherLiveWallpaper)
Weather (this is the com.htc.weatheridlescreen)
Weather Provider
Weather Widget

Once all is checked, click the lock button to the upper right of the screen. Ignore any error messages.

Step 2: Install battery saving app

Choose from Easy Battery Saver, Juice Defender, Battery Defender, etc.
Each app has its own settings. Another article will explains how each works.

Step 3: Disable default connections
Disable 4G, Wi-Fi Hotspot, GPS, Bluetooth, Mobile Network, and Auto Sync.

Go to Wifi Settings and switch it to “Always” for Keep Wi-Fi on during sleep

In addition, install Wi-Fi Matic from the Google Play Store so it will automatically turn off Wi-Fi when you leave your home or office.

Also decrease brightness to 20% or less.

Step 4: Install Productive Apps
For free texting, install Google Voice
For your Microsoft Office replacement, install Kingsoft Office
For antivirus protection, install Lookout
For media, install MX Player
For browsing, add the “Adblock Plus” add-on to Firefox
For capturing documents for school or work, install CamScanner
For reading PDF, install Adobe Reader

Step 5: Analyze the Results
After I performed the tweaks, the phone can last (with minimal use) about 2-3 days without charging. (Note: This is only if you disable ALL the apps that I listed in Step 1. Actual mileage may vary.)

After the final tweaks, the apps running the background would be: (Note I said background)
Wi-Fi Matic
Google Voice
Lookout
Easy Battery Saver
HTC Location Service
Media
Google Services
Google Services
vDM Client
Touch Input

All the other apps are not running in the background or are disabled.

Other tweaks: I removed the clock from the homepage and instead put the Google search bar in the front and then all my apps under it.

By tweaking the FreedomPop Phone, you ensure that your HTC Evo Design 4G’s battery life would last longer.