truck wont crank

[mrman]

2018 ram 3500 kept in garage heated to about 50 degrees, truck has about 22k miles it's like new. she's been parked for 4 or 5 days today went to start her and all the lights came on like normal i waited for glow plug lite then pushed start button. heard loud thump no start all lights came back on, then i got a service 4 wheel drive system code?? still no start. so i put a charger on passenger battery gauge showed low, i let it sit about 30 min still same thump. so i hooked up another charger to drivers side battery and truck fired right up. Really what's going on here this truck is only 3 years old. my 04 dodge 2500 sits outside and the batteries lasted 14 years, so why would this new truck not want to start. I went and drove truck down hwy and back truck shows charging 14.3 volts, went to store shut her off and she fired back up no problems?? please explain this to me..

 

[GTyankee]

Auxiliary battery is not meant for starting

Find yourself a trickle charger to mount under the hood

The Ram Voltage Regulators are built into the Alternator & the Rams brain controls the output, unfortunately, the charge cuts off at something like 80 to 85 %

A trickle charger would keep the battery much closer to 100% & a good one cuts off before it can overcharge

Todays batteries are not as well built as they were 20 years ago & tend to fail at about 4 years & if a truck has 2 batteries, you need to run a battery isolator, so that the 2nd battery has less of a chance of drawing down the primary battery

 

[mrman]

Ok thanks for the info can’t believe this happened after sitting 4 days guess I’ll get a battery tender