Originally Posted by TallMomof2
Honestly, I don't see much of a difference reading off the SD card.
That might depend on the specific card, undoubtedly some burn more juice than others. Checking the web I found the power used by some were 35-80mA for writing.
I've learned that the Kindle indexes new books. I had loaded 80 or 90 all at once and put them on the SD card.
I'm wondering how long it would take to index those books. This would keep the CPU and the SD card active, and if the indices were being written to the SD card - That would use the most power of all.