Charging system or bad battery

I'm having issues with my 2002 pre runner with a 3rz 4cyl . I'm having charging system or battery issue only in very cold winter temps . I've had this issue for the last two years only when it's very cold outside

This recent issue started about two weeks ago with very slow cranking over only on the initial start up for that day . All other times it started normally . This morning after parked in a non heated garage for two days and the battery was dead

Checked the voltage on the battery and it was 11.46 volts . I had the battery charged but only went to 12.6 volts fully charged . Put the battery back in my truck and it started up with issues . Checked to see if the alternator is charging and was seeing 14.0 volts .turned engine off and saw once again 12.60 volts

Like I mentioned earlier this is a 1.5 yr old battery and this is my daily driver so I do put alot miles on it

 

You could have a small parasitic draw drawing just enough to bring the battery down and not start on a cold engine.

But I’d go with a bad battery first.
Batteries aren’t made like they used to be.
3 years is avg. on newer vehicles.

And it’s not uncommon to see some fail within a year. (Poor quality batteries)

 

Sounds like the charging system is fine if the alt is putting out 14 volts. And a resting voltage of 12.6 is in the normal range. The real question is how long will it hold that 12.6 volts. Sounds like it isn't holding that for long enough. A battery should be able to start the engine when it's resting voltage is as low as 12.2-12.3 volts.

Rather than wait two days, check to see where the voltage is the next morning.

Another troubleshooting option would be to disconnect one of the battery posts and check for voltage drop over time. If it holds the charge and doesn't drop, it probably isn't the battery that is causing the problem.

 

Take the battery and get it load tested. If it’s only 1.5yrs old it should have some sort of pro-rated warranty. I agree with @TnShooter batteries don’t seem to last as long anymore.

When I got my Tacoma I moved an old optima yellow top from my rolled ranger. It lasted almost 10 years before I needed to replace it. Since then I’ve gone through 3 batteries and they typically need to be replaced in 3 years. I now have a super start platinum from oreillys that I’m hoping will last longer than that.

 

Charge the battery fully. With a volt meter, I prefer an analog meter, older needle style but a digital one will do, set the meter to DC volts 12 volts scale and put one lead on the post on the starter where the battery cable is and put the other on the positive battery post and have someone crank it over. Any reading above .3 volts is telling you you have a bad cable. This test should be done on the ground cables also.

 

This morning I checked the battery and voltage dropped down to 12.38 volts so I decided to call Autoclub to check my battery . They tested my battery and found the Alternator is providing 14.5 volts . The resting voltage after the engine was turned off was 12.7 volts and the battery was only showing 30% charge

The battery being at 30% charge even after driving it on the freeway the day before should have fully charged the battery . That told me the battery was bad so I had the tech replace the battery

The tech noticed the battery cable terminals have been overtightened especially the negative side. So those will be replaced soon . He tested the battery after the installation and it showed 14.5 volts with the engine running and 12.7 volts resting voltage

I just checked the battery voltage and it's at 12.65 volts and holding

 

Of course it's going to show 14.5 volts with the engine running, that's the alternator doing that.
You need to check and see if something is drawing power when the truck is off. How to test for a Parasitic Draw – Innova

 

Yes 14.5 volts does indeed show a good alternator , any voltage above or below that shows a malfunctioning alternator , There is paristic draw now being seen with new battery