2nd Gen Non-Engine/Transmission Thought I needed a new battery

[kshimizu]

The past few days my truck was taking longer than usual to turn over and start. I went by Sam's Club and had them test to see if it was the batteries. They tested both and said that the driver's side battery was no good. I didn't have time to change it right then so I went back yesterday to buy one. The truck was still cranking with less juice than normal until I got there. I paid for the battery and the guy was getting ready to put it in. He checked one last time to make sure which battery it was that was bad and both batteries showed up being good. He brought out 3 different testers, all showed good. Put everything back how it was closed up the hood, and it started up like nothing was ever wrong. Really weird, but it saved me 100 bucks for now.



Any suggestions on what really happened?



Kyle

 

[Bob Wagner]

and both batteries need to be replaced at the same time

 

[AstroZombie]

Why do both need to be changed at the same time? A bit of a noob so please be patient.

 

[willyslover]

Check your ground straps... and the surface they attach to ... needs to be very clean at the attachment points

 

[ToolManTimTaylor]

Both batteries in a dual battery system need to be changed out at the same time due to several factors.

Mainly If you replace one ... The other most likely is weaker and will draw upon the new one. Which in turn can dramatticly shorten cell life. Plus you can invite a vissous cycle of swapping a battery in and out every six months. as one will become weak ... you replace it then the other ... you replace that . . then the other blah blah.





*Edit*



Clean your terminals well and grounding points too as that had caused my truck to have a seroius power and shutoff issue.

 

[WestTN]

Why left battery seemed bad...

The original problem was likely a dirty connection to the left battery, meaning you were cranking only on the right battery. They would have to disconnect one of the batteries to be able to check them independently. That probably cleared the connection, so then the battery checked good.

 

[mental floss]

Hey... . This happened to me just the other week. Checked both batteries and they were fine but put new batteries in and it fixed the problem of slow starting. The only thing I can figure is that the batteries are good enough for a gasser but to heat the intake and turn it over they just can't do it. Just my 2cents.

 

[JohnE]

Not all batteries created equal.



I put in Exide replacement batteries and they couldn't handle running my Espar and starting the Cummins on a reliable basis. Both batteries passed load test, too. They were not group 27 batteries which have the reserve capacity (RC) to handle extended drains especially from an Espar. I dumped the Exides and got Sears Diehard Gold which are a true group 27 batery. No problems running the Espar and then starting the Cummins. BTW, DO NOT get the Truck/SUV series from Sears as they are not a group 27 battery.



FWIW

The family business was a John Deere dealership about 25 years ago. We never had troubles replacing a single bad battery in a twin battery system, but we only sold JD labeled batteries. JD label batteries used to be produced by Gould, which was a top notch battery. Unformately, Gould does not make JD batteries anymore so they switched to Exide. Re-read my above experience with Exides.