A thread here discussing cards warns that some cause bttery drain. Do u have a card, and how long doe your batt last?
I'd think that would be for Apps on the card more than the actual card. Think about it a moment. The card is constantly being accessed for frequently used Apps... That would naturally be more battery intensive than internal memory.
I keep all my Apps stored on my phone and use the SD card foe media. I've got 32GB on board so there really is no problem for me working it this way.
My SD card recommend. Known Name Brand. If you never heard of it, stay away from it. I've a San Disk 64GB Ultra Plus microSDXC UHS-1 class and no worries. Format 64 GB and higher as exFAT, 32GB and lower as FAT32 (or just let the phone format it for you, it knows what it is doing).
I'm a light to moderate user and regularly get 2 to 3 days battery life. On a recent 32 day trip overseas I used my 1520.3 as a power user + with about 100 pics a day average, sometimes video as well, web searches, texting, Skype, navigation, Bing Translator, etc. etc. My battery lasted me each and every day for 12 or more hours in the field except on 2 days where I resorted to a 2800 mAh Halo recharge stick.