It is very unsecure to store large amount in Android.
Why? And as opposed to what?
Android is not secure enough AFAIK. It is better not to store Bitcoin in it. If you know what you are doing and how to handle, then you can use any OS but OP is a newbie, so I am not willing to suggest OP to store whole balance in an Android.
I suggest you to export all the addresses created in mobile to your PC but don't export addresses in PC to mobile.
Why?
He said
- he don't want to loose his BTC.
- he is a traveller.
Exporting addresses from Android to PC will secure those addresses even if the phone is lost(one of the concern of OP) and as I said, I don't think Android is secure enough to store whole balance. So vice versa, i.e. exporting addresses from PC to Android is not good.
Store small amount in mobile and bigger in PC.
Why? Malware which targets mobile devices is considerably less common than PC-based malware, and some mobile devices are currently invulnerable to bitcoin-stealing malware (those which cannot yet be easily rooted such as iOS 8.3, most boot-locked android phones running 5.0.2, etc.).
OP is using an Android phone. By mobile, I mean 'Android'. Sorry! I should have told earlier. There are some reasons. If you also consider practical problems additionally to technical problems, I don't think it is good to store whole balance in a mobile especially when you travel a lot.
If there is any mistake, please correct me. Thank you!