Another dying alternator?
I was replacing a brake line and caliper last night. I had the brake pedal blocked down to stop the fluid from draining out and didn't unhook the battery. After 3 or 4 hours of monkying around, the battery died. Got it jumped and took a quick 2 minute test drive and it was fine. This morning it had ZERO juice. The LED on my cig lighter voltmeter didn't even light up. Got it jumped again and made it to work. I can hear the alternator whining, so I know it'* going. The voltage hovers in the low 13'* when moving or reving, and drops to 12 when I brake or idle. When I shut the car off when I got to work, the voltage went to 11.9. 3.5 hours later, it'* sitting at 11.5.
The battery is a 6 year old Optima yellow top, charged by a 3 year old Napa Raylock rebuilt 140 amp alternator. I figure the alt is gone. Opinions on the battery? This will be the 3rd or 4th alt to die during the life of this battery so far.