Just got a new (original) Nokia battery. Charged it the whole night yesterday, still full bar until now with slightly heavy usage. Does this mean?

• The 6-mth old battery was has degraded (by now, normally reduced 1 bar)?
• Problem with the battery indicator?
• Longer charging = longer lasting?

Will continue to monitor the battery differences. By the way, anyone knows how BatteryGraph monitors new batteries vs old (because I noticed the mAh and mv were the same)? Does it even matter?