This (slow charging) issue just started for me too since latest (5.1.1) update. Charging time was OK before.
Now a full night plugged gave only about 50% charge.
Tried different cables and AC adapters without any difference.
In last resort I've made a full wipe and flashed factory image without any improvement
**EDIT**
Just ordered a POGO cable, hoping improvement.
In my experience, the N10 is the pickiest device ever when it comes to cables and chargers.