I could use some help diagnosing a developing problem...

I'm not driving as much - like most of you these days because of covid, but I still drive almost every week and when I do drive it is at least 25-minutes which I expect should be sufficient to keep everything in order.

Car is ~16 months old, ~12k miles.
Auto Idle Stop has not worked for about 6-weeks - worked on most drives prior to that.
I tried the Auto Idle Stop "fix" involving opening the hood and starting the car about 2-weeks ago, but still no auto idle stop
The car "seems" less eager to start the last several times (slow cranking)
After today's drive, I checked the battery which read 11.89 VDC - I was expecting 12.4 or more
I started the car (started right up) and checked the battery with the car running which read 14.4 VDC - meaning the alternator is ok?

Do I have a die-ing battery? How can I confirm this - and replace it before getting stranded?
What other possibilities match these symptoms?

Thanks for your help
B

 

yes, dying battery.
it should hold at 12.2-12.4 volts when the car is off.
anything less, battery is no good.

 

Should be under warranty, see your dealer.

 

I wouldnt stick to a honda battery if it died in less than 2 years.
Interstate batteries are great, so are anything made from Johnson Controls.