With “regular” cars and trucks, I have found that 4-5 years the average lifespan for today’s automotive batteries.
In my wife’s previous car, we put in the super Gee whiz AGM battery, and we got the exact same 4-5 year lifespan......bummer.
The AGM battery will run $190+, and Old fashioned wet cell batteries are running about $150.
I echo the previous advice - go to your local auto parts store ASAP, and have your charging system tested. If the batteries are in fact toast, invest in 2 new batteries of your choosing.
After spending 35% more on the AGM battery on my wife’s last car, and getting the same lifespan as the less expensive wet cell lead-acid battery, I would choose the less expensive old fashioned wet cell battery.
Based on my wife’s car battery dealeo, my previous truck battery up and died like 4-1/2 years or so, last year, and I went to Costco, and picked up the old fashioned wet cell Interstate brand battery for like $130. My recommendation = if you need 2 new batteries, charge up the existing ones enough to drive to your local Costco, and buy 2 new Interstate batteries.
Good luck!