12.5 volts is low. Your battery may be borderline and on the way out. Regardless of age, any battery can fail at any time.

First thing I would do in your case is clean and burnish your battery terminals. then be sure that the cables are tightly connected.

 

^^^^ No truer words...

First battery in my Toyota Tundra lasted over 9 years. So... I of course replaced it with same. Dead in less than two year.

Back in the day batteries would tell ya they were dying. Slow cranking would last for weeks even months. Today, batteries seem to die a quick death once the first symptom occurs.

 

^^ Yep, today's batteries cost three times what they did a decade or so ago, and they typically last about half as long. Many techs blame this on the fact that today's vehicles are essentially rolling computers that eat power like Joey Chestnut eats hot dogs every July 4th.

 

The newer vehicles are the root cause as they constantly draw current when not running. A drip over time empties out the reservoir. Using a battery tender helps increase the life.

Salim

 

FYI as ive had people PM me if i solved this.... with a new OEM battery the problem was resolved and hasnt reappeared. I'm going to say the previous battery was a defective unit. Shameful quality/durability from the previous battery as it wasn't abused (vehicle driven several times per week for trips over 10km at speed)