The battery bar is often unclear to read because of the small size off. Apple has chosen the option to also show your iphone battery percentage. This gives you a much more accurate impression.
Setting Battery Percentage
1. Go to Settings
2. Now click on General
3. Now click on Use
4. You can now turn on Battery Percentage on top of the option.
You will see right next to the original battery status bar is the percentage of your battery.