Google Nexus 5 :: Not Charging Correctly - Battery Calibration Required?

I recently had an issue with my Nexus 5 where it wouldn't charge correctly and only charge something like 30%-60% in 8 hours or 0-70% in 16hrs. I replaced the battery and it is charging as it should now.

I noticed the other day though that once fully charged it went from 100% to 89% in about 20 mins then operated as normal so I assume it needs to re-calibrate the battery. When I swapped the battery one was reading 50% and the new was on roughly 30% so it may have thrown it out a bit. Is it just a case of discharge fully then fully charge or do I have to charge this when off?

I've read a few threads and also found this:

1. Once your phone dies plug it into your HTC charger, (DO NOT TURN IT ON)
2. Let it charger fully (about 3 hours) until you see the light turn green, unplug the phone
3. Turn on the phone on but do not mess with it. (no checking email, messages, etc) let it sit for about 20 to 30 min
4. then plug it in again but let it continue to sleep (about 30 min)
5. once the light is green, unplug and your finished.

It was under the HTC one s forum. Does that apply to the Nexus 5 also? The phone is not rooted.