I can save battery life on my iPad.
“I use my iPad as a computer/tool.”
If your battery is running at like 20% you can turn down your brightness by scrolling up on the bottom of your screen and turning the brightness down.
In “Settings”, you can turn on airplane mode. If you turn airplane mode on, it will turn your WiFi off but, when you need it again, just turn airplane mode off. This tip really help me when I have low battery.