2020 GMC Sierra 1500 - battery dead already

Same issue as above. Went to stat my 2020 GMC sierra 1500 yesterday and it was dead. 7.5 volts. Jumped it off and drove it for about 30 miles to charge it. Check engine light came on. Low battery, Anti-lock breaks and engine/transmission. Appointment with the dealer tomorrow.

One—W can not see “issue as above”.
Two—How did you break your anti-lock?

All the lights are caused by the low battery. I seriously doubt anything else is wrong. The alternator isn’t made to charge a dead battery, you need a charger for that. The dealer will test the battery and alternator, and replace whatever’s necessary. I wouldn’t normally expect such problems on a 2020 model but it does happen.

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You did NOT charge the battery nearly enough in a 30 minute drive. The battery needs to be on a battery charger of some size - 10 amps or more - at least overnight.


Besides giving a full charge, make sure that you do the diagnostic work to find out why the battery discharged. It could be a door ajar or it could be a totally bad battery or alternator…or many other things.

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I would hope that the OP would hold the dealership’s feet to the proverbial fire, and insist that they do a gratis diagnostic check on this one year old truck.



This is warranty work, and the dealer has to find the cause, including a determination of how the owner’s habits might have contributed to the battery discharge. I’m not saying that the OP caused this, but it is possible that a series of short drives without a long one to recharge the battery may have led to a dead battery.