I updated my iphone 5 on ios 8.4 now my mobile is draining too much battery and heatup should i change my battery???

Greetings Haryx khan,

After reviewing your post, it sounds like the battery is draining and the iPhone is warm when charging. I would recommend that you read these articles, they may be helpful in troubleshooting your issue.

Apple - Batteries - Maximizing Performance

Tips for iPhone, iPad, and iPod touch

Keeping iPhone, iPad, and iPod touch within acceptable operating temperatures - Apple Support

When using the device or charging the battery, it is normal for it to get warm. The exterior of the device functions as a cooling surface that transfers heat from inside the device to the cooler air outside.

Thanks for using Apple Support Communities.
Take care