Dead battery issues

[Ironhide69802]

Went to start truck the other morning and it was dead. Charged batteries up and it drove great. Shut it off and dead again. I'm thinking dead cell in battery or both batteries. Could it be more than that? Thinking about changing batteries and go that route. It did show battery light on dash gauges. Ideas or you think batteries then try again? Thanks.

 

[Dustball8504]

How old are they? I had an issue like this with my 6.0 and it turned out to be the alternator was shot. I'd also check the voltage off of it and make sure it's putting out enough. I had mine rebuilt and it was better than new and cheaper than batteries.

 

[Ironhide69802]

Bought truck month ago. Not really sure. I know a dead cell will do that. Didn't know if it would run without a good alternator. The only way to charge it was hook up jump box to one and car to the other. I ran it 30 miles to charge them and found dead again

 

[Ironhide69802]

Truck has 100k on it

 

[Dustball8504]

My alternator was shot at 80k for reference. I even put new batteries in before I looked to the alternator and they were dead overnight, mine had a constant draw to it when the alternator was going out.

 

[speedracer1000]

sounds like the batteries are junk if you drove the truck for 30 miles and it ran fine and didnt die id say the alternator was working, at least somewhat. if you take it to advance auto parts or some place that does testing they can tell you wut the alternator is puttin out and load test the batteries, reason i say take it to them is cuz they were the only ones in my area that i found could do a parasitic draw test, with the key off. if its drawin more than it should be u have a draw somewhere.

 

[Kbryant777]

Disconnect both batteries and charge both batteries up check with a meter. If it has a bad cell the battery will discharge itself down to 10v if it has more then one cell bad it will discharge even more. And if you have on good and one bad battery the bad one is constantly pull juice outta the good one. Hope that helps some

 

[Zmann]

I just checked mine for a slow start and one was down a few volts

I just make life easy and go the the parts store and let them load test

I wound up with two new Autozone Platinums (AGM) what a difference


however they can also check your charging system on the truck first but I would still load test each battery

 

[Ironhide69802]

Thanks guys. Gotta put my big truck in Freightliner Tuesday so I'll be checking them then.