Battery Voltage

[skeetjunkie]

Out of curiosity I checked the original battery in my '04 X5 3.0l, which after 6+ years has never acted up. She had been sitting idle in the garage for the past 2 to 3 weeks

Inspected the hydrometer which showed a "black" eye, indicating inadequate charge. Performed Bentley's open-circuit voltage test which showed 11.9v, indicating below 25% charged.

So what the heck, I pulled it and set it on a 12v 6amp battery charger for about 1.5 hours until fully charged. Retest showed 12.5v.

Ran her about the local roads for 1/2 hour - same voltage. Restest after 24hr idle - 12.3v, which Bentley sez is 25-75% charged.

Voltage test with engine running - 13.6v.

Not fretting, but wondering whether this battery still sounds reasonably healthy in spite of its age?