Re: No sd card. No swapable battery
My approach for battery swapping (in a Samsung, as it happens)....
Bought phone with standard (swappable) battery. OK by smartphone standards, but I'd prefer something with more life
Bought 2 high-capacity batteries (made by Samsung), and replacement back for phone (slightly larger to accommodate high-capacity battery, but not a great embuggerance)
Run the phone on high-capacity battery on a daily basis for normal operation. Swap the batteries over every so often so that the wear-and-tear is reasonably even between them.
When going on a long trip sans convenient charging facilities, swap batteries and charge before leaving home so that I have a fully-charged battery in the phone, and a spare in my bag.
If running low on juice while travelling, it's quite easy to swap the fresh battery in
Works for me. YMMV