Originally Posted by robkathybat
Now that we are both fully retired we don't drive the truck so much, mostly just towing. so it sits for longer periods of time. I know there is a certain amount of "parasitic" drain on any vehicles battery, some more then others. My truck has had the batteries drain twice this summer, with only being parked for maybe 2 weeks, The first time I thought I left something on, but nothing came on when I hooked up the charger. I have been very careful since but still had an almost dead battery after maybe 3 weeks sitting. I now disconnect both batteries when sitting. I starting doing this over the winter because it sits for much longer then and the one time I had to drive it the battery was dead. I had a Chevy Duramax a long time ago and there was a fuel heater relay that would randomly energize, draining the batteries. Does anyone know of something like this on Ram trucks.
If that's the original batteries on a '14 Ram I'd say you got your money's worth & time for a replacements.
If it's a diesel it will have 2 batteries, be sure to replace both with identical batteries. Adding a new battery to an old one will only shorten the life of the new battery.
Once they were dead the 1st time the lifespan was shortened considerably, 2nd time it was probably beyond saving at that point. Yes they may charge enough to start the truck..............once before it's dead again.
Unless you've got some sort of direct short there shouldn't be enough parasitic drains to kill your battery while sitting in a year let alone a couple weeks. I've left the dome light on for days & didn't kill the battery.