Originally Posted by xlphillips
Question first, then the scenarior.
Can charging 2 6V batteries while driving kill an alternator and battery?
I have two 6V batteries. I left them at the RV repair to check/charge (they were dead)...and they didn't get around to it. They told me I could charge them up while driving 8 hours from San Diego to Phoenix. I drive a 2007 Jeep 3.7L, 6cyl, 2 WD.
About 4 hours into the drive, the red battery light when on, on the dash. I didn't do anything about it (face palm).
I parked in Phoenix, then used the car for about another 60 miles, not pulling the trailer for the next two days. The battery light was on 1/2 the time.
The car ended up malfunctioning (eg wouldn't start or drive well and had lights flashing intermittently, and gave a U?141 code on the ODB), so I had the dealer check it out. They diagnosed need a new alternator and battery. The alternator is original (175K on the car), the battery is 1.5 years old.
So here is my question: can charging those 6V while driving kill an alternator and battery?
Thanks! Love the answers on this forum.
Erica from San Diego
175K could have a lot to do with the failure, but, alternators are meant to
'maintain' a battery's charge. They are not 'battery chargers'. 8 hrs. of charging at max output of the alt. very possibly fried the internal circuits, and if one battery was defective, shorted cells, the alt would continue charging because the battery would never fully charge.