Q: iphone 5s battery drain ios 9.3.2

Hi ..

Try the suggestions here >   http://www.apple.com/batteries/maximizing-performance/

Follow the 3R's- if a restart does not solve your problem proceed

User troubleshooting is:

1. restart, ie power off/on,

2. reset  http://support.apple.com/kb/HT1430,

3. restore from backup, restore as new device. http://support.apple.com/kb/HT1414

Can you walk into  your local mobile carrier for support.

If you are far from a tower and the signal is weak the battery will run down much faster.

How is your cell reception where you are? As you explained the battery performs well when on WiFi, but is problematic when on cellular service, that may very well be where your issue lies.

Along with the previously suggested battery life article, this one is a good read as well. If you're in a low cell reception area, your phone will work in overdrive to keep that connection. If it is set to manage a lot of different tasks while on the cellular network on top of low reception, that can spell trouble for your battery.

About cellular data settings and usage on your iPhone and iPad - Apple Support