Finally stranded me...

[jyi786]

Last week, I was out of town with my 2012 Yukon Denali XL. I was in Richmond, and I live in Maryland, so it's a bit of a hike.

Anyway, I was going back to the truck, and remote started, and it clicked, like it was getting ready to start...and then after 3-4 seconds *reluctantly* started. This was very strange to me, but I thought nothing of it, especially since the truck seemed to run fine. One more remote start cycle, and it worked fine. Parked in a restaurant parking lot and went to have dinner. Came back out, and remote start, and *click*....nothing. My heart dropped. Got into the truck, and same thing: tried to start, single *click*, and nothing. First thought was that it was the starter. Didn't think it was the batteries, as I have dual batteries. I had to leave the truck in the parking lot overnight.

Ended up having to get a hotel and looked to schedule a tow for the next morning, since I got stuck in town. While I was in the hotel, I did some research and found that most people said it was the starter, and that it probably would work fine if left alone to cool down. I also looked up two dealers; lo and behold, Hendricks Chevrolet/GMC was literally a block from where my truck was parked.

The next morning, I went back to the parking lot, and what do you know: the truck started right up. I took it right to the dealer, and asked them to diagnose. They came back and said one of the batteries and the starter was bad. I was in no position to argue, so I just told them to change all 3: the starter and both batteries. They did...to the tune of $1300. The work was completed in less than 2 hours. Pretty impressive to me. Got the truck back home and everything is fine and dandy. One thing I noticed is that the truck no longer coughs/sputters when starting up: it starts up smoothly, clean, and very strong.

The truck is at 150K miles, which is right when I've read that the starters start to give out. I do believe what the dealer said that also one of the batteries finally died, but the other was masking it, causing it to be unable to supply enough power to crank, but just enough to power everything else in the truck. I've resolved to changing BOTH my batteries out every 3 years.

Think I did the right thing here? They replaced my batteries with 2 AC Delco 48PGs. Are these good batteries?

 

[swathdiver]

Last week, I was out of town with my 2012 Yukon Denali XL. I was in Richmond, and I live in Maryland, so it's a bit of a hike.

Anyway, I was going back to the truck, and remote started, and it clicked, like it was getting ready to start...and then after 3-4 seconds *reluctantly* started. This was very strange to me, but I thought nothing of it, especially since the truck seemed to run fine. One more remote start cycle, and it worked fine. Parked in a restaurant parking lot and went to have dinner. Came back out, and remote start, and *click*....nothing. My heart dropped. Got into the truck, and same thing: tried to start, single *click*, and nothing. First thought was that it was the starter. Didn't think it was the batteries, as I have dual batteries. I had to leave the truck in the parking lot overnight.

Ended up having to get a hotel and looked to schedule a tow for the next morning, since I got stuck in town. While I was in the hotel, I did some research and found that most people said it was the starter, and that it probably would work fine if left alone to cool down. I also looked up two dealers; lo and behold, Hendricks Chevrolet/GMC was literally a block from where my truck was parked.

The next morning, I went back to the parking lot, and what do you know: the truck started right up. I took it right to the dealer, and asked them to diagnose. They came back and said one of the batteries and the starter was bad. I was in no position to argue, so I just told them to change all 3: the starter and both batteries. They did...to the tune of $1300. The work was completed in less than 2 hours. Pretty impressive to me. Got the truck back home and everything is fine and dandy. One thing I noticed is that the truck no longer coughs/sputters when starting up: it starts up smoothly, clean, and very strong.

The truck is at 150K miles, which is right when I've read that the starters start to give out. I do believe what the dealer said that also one of the batteries finally died, but the other was masking it, causing it to be unable to supply enough power to crank, but just enough to power everything else in the truck. I've resolved to changing BOTH my batteries out every 3 years.

Think I did the right thing here? They replaced my batteries with 2 AC Delco 48PGs. Are these good batteries?

If your batteries are wired like the TP2 setup, one is for the trailer and the other is for the tow vehicle. You could use the trailer battery to jump the tow battery.

This recently happened to another member here, Bill @intheburbs

Did you add the second battery?

 

[jyi786]

I added the second battery myself. They are simply wired up in parallel using the stock GM battery kit, so basically acts like one battery.

I learned via research last night that I should be rotating (swapping) the batteries, side to side, every 6-9 months. It totally makes sense, since all the accessories are on the main battery. My guess is that I wore down the main battery; this is now the second time I've done so. Rotating the batteries will help level out wear, from what I read.

 

[Big Mama]

Good info for the next guy.

 

[swathdiver]

I added the second battery myself. They are simply wired up in parallel using the stock GM battery kit, so basically acts like one battery.

I learned via research last night that I should be rotating (swapping) the batteries, side to side, every 6-9 months. It totally makes sense, since all the accessories are on the main battery. My guess is that I wore down the main battery; this is now the second time I've done so. Rotating the batteries will help level out wear, from what I read.

Yeah, that's how my old GM diesels were, it was important to replace them at the same time back then. Never thought of rotating, good idea.

 

[intheburbs]

I'm sure Delco batteries are good enough. Personally, I buy construction, not brand. AGM for me.

And personally, I would have gone through the entire charging system - checking batteries and alternator, before replacing the starter. Not sure I buy the whole 150k starter dying thing. I currently own 7 vehicles, have owned a bunch in my lifetime, and can't remember the last time I replaced a starter. My two GMT900 trucks have 215k and 135k miles with original starters.

If the batteries are simply wired in parallel, I can't possibly see how "rotating" them could make any difference. Assuming you've used proper-gauge wires, any electrical load should be spread evenly between the two. Ditto charging current from the alternator.

I've had dual batteries in my Suburban since 2014, and dual batteries in my Denali since 2016. I don't rotate them and I've only replaced two out of the four in that time.

Also, as you've found out, if you don't use an isolator, there's really no benefit to dual batteries, it's no different than just having a larger single battery. If the truck doesn't start, you still need a jump. One time my Denali died, the primary was so dead it wouldn't even engage the isolator. People watched me get out my cables and jump-start myself. Jaws dropped at my sorcery. LoL

 

[jyi786]

If the batteries are simply wired in parallel, I can't possibly see how "rotating" them could make any difference. Assuming you've used proper-gauge wires, any electrical load should be spread evenly between the two. Ditto charging current from the alternator.

I've had dual batteries in my Suburban since 2014, and dual batteries in my Denali since 2016. I don't rotate them and I've only replaced two out of the four in that time.

Also, as you've found out, if you don't use an isolator, there's really no benefit to dual batteries, it's no different than just having a larger single battery. If the truck doesn't start, you still need a jump. One time my Denali died, the primary was so dead it wouldn't even engage the isolator. People watched me get out my cables and jump-start myself. Jaws dropped at my sorcery. LoL

The only thing I know that leads to credence to rotating the batteries, for me, is that the primary battery has been the one to die....twice now. The first battery came with the truck. The second, I bought brand new, a Duralast AGM. My secondary battery, a plain-jane Duralast, has outlasted both of them.

Not to say that there is no benefit to having dual batteries; if I didn't have it, I'd be stranded in an even worse situation. Having dual batteries helped me to be stranded in the best of situations (not like it's too much different), but at least it didn't shut down on me while driving. Also, having this happen has helped me to learn to be much more proactive with my batteries now. I'm going to start swapping them side to side every six months, and simply change them outright at 4 years.

I also still believe the starter went bad. One of the batteries held enough charge to start it up with no problem at all, and/or run all the accessories by itself. The single *click* and nothing was the starter, straight up. Only when it cooled down from the heatsoak the next morning, did it fire right up.

Not disagreeing with you though, you're absolutely right. I guess in my circumstances, what I'll be doing with the batteries costs me nothing (other than the ridiculous price I paid at the dealer), and the new starter gives me peace of mind.

 

[iLikeEggs]

What was the parts/labor cost on the starter?

 

[Bill 1960]

Uneven battery utilization in parallel IS an issue in multiple battery setups where the wiring isn’t done properly. The resistance of unequal length cables will cause the battery closest to the loads/ charge source to do most of the work. It’s pretty well known in the RV community which is where I learned about it.

I do not know if GM used proper wiring. But before I would go to the hassle of rotating batteries IF they took a shortcut, I would just correct the wiring. Which is dead simple. All positive feeds from battery 1. All grounds connect to battery 2.

Here’s a link explaining.
https://caravanchronicles.com/guides/how-to-connect-two-batteries-in-parallel/

 

[Joseph Garcia]

I'm sure Delco batteries are good enough. Personally, I buy construction, not brand. AGM for me.

And personally, I would have gone through the entire charging system - checking batteries and alternator, before replacing the starter. Not sure I buy the whole 150k starter dying thing. I currently own 7 vehicles, have owned a bunch in my lifetime, and can't remember the last time I replaced a starter. My two GMT900 trucks have 215k and 135k miles with original starters.

If the batteries are simply wired in parallel, I can't possibly see how "rotating" them could make any difference. Assuming you've used proper-gauge wires, any electrical load should be spread evenly between the two. Ditto charging current from the alternator.

I've had dual batteries in my Suburban since 2014, and dual batteries in my Denali since 2016. I don't rotate them and I've only replaced two out of the four in that time.

Also, as you've found out, if you don't use an isolator, there's really no benefit to dual batteries, it's no different than just having a larger single battery. If the truck doesn't start, you still need a jump. One time my Denali died, the primary was so dead it wouldn't even engage the isolator. People watched me get out my cables and jump-start myself. Jaws dropped at my sorcery. LoL

I have dual batteries, but there are not connected at all times. I have a high amp quick-disconnect connector on the second battery leads that I connect to the charging system once a month for about 50 miles of driving to keep that battery's charge topped off, and then I disconnect. My hope is that if I have a primary battery failure in the future when I am away from home, I can simply reconnect the connector on the second battery and keep me going.

Regarding starters, my starter on my 6.2 failed at 130k miles.