Hi!
Make sure you're using iPad in optimal temperatures, which is between 0ºC/32ºF and 35ºC/95ºF. The temperature range for storing iPad is much more generous. You can store your iPad in temperatures between -20ºC/-4ºF and 45ºC/113ºF.
You can also use Low Power Mode to decrease the amount of battery drainage:
To turn Low Power Mode on, go to Settings > Battery. You can also turn Low Power Mode on from Control Center. Go to Settings > Control Center > Customize Controls, then select Low Power Mode to add it to Control Center.
(Use Low Power Mode to save battery life on your iPhone or iPad - Apple Support)
Turning off background app refresh may also help with saving battery:
- Open Settings
- Tap General > Background App Refresh
Furthermore, you can turn off your iPad when you're not using it for a few hours to prevent significant battery loss. I do this overnight, and, from my experience, my iPad stays at 100% for the whole night. If you need any assistance with this, be sure to check out the first couple steps of this article: Restart your iPad - Apple Support.
I also recommend keep your iPad up-to-date with software updates. Here's how to check for updates on iPad:
1. Go to Settings > General, then tap Software Update.
2. If you see more than one software update option available, choose the one that you want to install.
3. Tap Install Now. If you see Download and Install instead, tap it to download the update, enter your passcode, then tap Install Now.
(Update your iPhone or iPad - Apple Support)
I hope this answers your question!