The resistance through the voltmeter is so much greater than that of the resistor that the resistor's resistance has negligible impact on the circuit. A precise-enough voltmeter would see a very small difference, on the order of micro or nanovolts.

Why does the potential drop across a battery and resistor equal the emf of the battery?
I recently got a Motorola Moto G (4.3 upgraded to 4.4.2), and I wasn't getting the battery life that my vendor claimed I would get (Through mixed usage: 2-3 hours of music, some web browsing, a lot of Whatsapp, a little bit of gaming, and Wifi/mobile network completely turned off in the night (for some 8-9 hours), I barely touch 20 hours of battery life)

I was wondering whether this has got to do with the 3 google accounts that I've kept in sync for GMail and some other Google services.

I may be a bit paranoid because my previous Android phone suffered from woeful battery near the end of its life, but still I would like to know if syncing more accounts drains the battery more or not.
