5th gen battery periodically needs a jump need help

I have a 5th gen (2014) with 210,000kms sr5 premium. In the last 2 weeks, I needed a jump. Nothing was left on, lights, etc. I replaced the battery 6 months ago. I tested the battery and alternator with a multimeter, battery at 12.9 and when the vehicle turned on with radio, lights, and heat it measured at 13.7.

I am at a lost of what this could be, any ideas.

Thanks in advance

 

Have the battery load tested. It could be a cell starting to go bad.

 

Sorry to hear that you're having battery issue. What is the make and model of your faulty battery?

 

There could be a number of causes. Next step IMO would be to check for a parasitic drain. Also, do you have any aftermarket electrics, such as lighting, remote start, alarm, etc.? If so, disconnect all of that and see what happens.

 

After years of getting great Panasonic batteries from Toyota, I finally got a dud that Toyota replaced after a couple months. Stuff happens.

 

Agreed. My SIL got a new battery for his Lexus from Wally World, and it stopped holding a charge after a few months. They replaced it on the spot, no issues since.

 

What battery do you have?
AGM...?