How to tailgate without killing the battery?

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atrZ71

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My battery died after having the tailgate open for an extended period time. The lights and infotainment screen we're not on at the time and the key was not around either I just had the tailgate open. Is there a way to leave the tailgate open for an extended period of time without killing the battery? Or do I have some problem with my 2021 Z71 Tahoe that is draining the battery while the tailgate is open?
 

swathdiver

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How about the headlights? If they were off too, then I would say your battery is weak. If and when you go replace the battery, get one with a higher reserve capacity.

For example, GM specifies the 94RAGM/8886452 battery for your truck which has a reserve capacity of 140 minutes. That's a long time already. The optional 94RAGMHR is 150 minutes.

If your battery is draining down this fast, it may need reconditioning. Lead acid batteries have plates that need to be desulfated after a while to keep them charged up. Yours needs that or something like that. I'm not familiar with AGM batteries.
 

GMCnewbee

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I leave my tailgate on our 2022 Denali open all the time. Sometimes for many hours. I have not had any battery issues (yet) at all. I was thinking (hoping) there was an automatic shutoff of all the various lights.
 
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atrZ71

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You are saying that the tailgate being left open is expected to draw additional power vs. when it is closed even if all screens and lights are off?
 

bill1013

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Isn’t there a switch that allows you to turn off the interior lights off when the doors come open. My 1999 Tahoe SLT had a dome light switch. I never liked having the lights come on at night. I also had the experience of the kids playing in the truck, going in and out. I get in and the battery is dead. I turned off the dome light and never had that problem again.
 

Doubeleive

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You are saying that the tailgate being left open is expected to draw additional power vs. when it is closed even if all screens and lights are off?
no if the key is off or not around the entire system should power down after 10-15 minutes, the interior lights going off is a sign that it is powering down, even if the hatch or any door is left open, really no different than leaving the headlights on or radio playing while sitting in the vehicle with vehicle off without opening the drivers door (or without turning accessory mode on.)
 
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atrZ71

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The dealership tested the battery and I had bad cells. I'm still concerned that the battery will be drained again from having the tailgate open for too long, I think it's crazy that an open door can kill the battery, I would expect all electronics to turn off after 10 min or so.
 

Chad G 1979

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The dealership tested the battery and I had bad cells. I'm still concerned that the battery will be drained again from having the tailgate open for too long, I think it's crazy that an open door can kill the battery, I would expect all electronics to turn off after 10 min or so.
If the battery had a bad cell, it won't hold a full charge let alone a long charge. Bad cells can cause a battery to drain in a very short time. We use battery powered buggies for maintenance at my work, and one guy for weeks had to have it plugged in overnight (16 hours) and then drive his toolbox to where he was working for the day (less than 5 minutes) and then plug it in again. So it likely wasnt the vehicle draining battery fast, but more so the bad battery just dying that fast. Our buggies use 4 batteries so that tells you how fast one with a bad cell can die
 

Mean_Green

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Any door or tailgate alone being open should not draw any power at all. Courtesy lights might be the only thing and they typically power off after a few minutes and they can (should be able to) be bypassed. As noted above, mine has a bypass switch on the headlight control so they do not come on with any door open. Is there some security function on the newer models that draws power with a door open? Even at that, most vehicles have a timeout for all power to conserve battery if a door is left open unintentionally.

If the dealer just replaced the battery, now would be the time to test it. Leave the tailgate open while at home where you have another vehicle to jump from or a charger.
 

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