Could it be the battery?



I have a 2004 colorado and the battery drained in just a night. I checked the battery’s volts and it read 5.5. Then I gave it gave it some juice by using cables and another car. My truck started easy then I checked the battery again while it was on and it read 14.4v, therefore the alternator is goon. I left it on a while then turned it off. I checked the battery again and it read 12.3v and the truck started easy again. I dont know what can it be… could it still be the battery?


I would suggest having the battery and charging system checked at an auto parts store. They generally will do this for free and generally do a good job.

You could have had (and may still have) some corrosion or other cause of a bad battery connection. You could have a dark drain, that is a light in the the trunk type thing that drained the battery. It is also possible that the battery is defective, or that it was made defective by allowing it to drain that low.

Have you checked the electrolyte level? How often do you drive that car? Has it had any history of battery/electrical problems?


first of all you don’t know that the battery drained in one night…it could have been low and reacheded its no start point … first clean the terminals and check the voltage in the morning for the next week…if it remains about 12V overnight it should be ok. if it is a sealed battery make sure the fluid level is okay…you can’t add any to it.


The car is my daily driver and I keep the engine and all of its componets clean. There is no corrosion on the battery , terminals or wires. Every light was off. The next day the battery was drained again. I will take the battery to get checked at my local autoparts. Thanks for the help.


I said that it drained over night becuase the night before when I arrived home I parked, then about 15-20 minutes later I went to move it to another parking spot and it turned on easy. Then in the morning it was dead. It has no corrosion anywhere on the battery or cables. The battery is the original that it came with. Thanks for the help.


I agree with other posters. A charging system check can be done for free by most parts stores, and will pinpoint the source of the problem. I just had a similar experience, and it was a battery that was loosing capacity as they performed the test. I replaced mine immediately. No problems since.


In general, if you ask that question then the answer is almost always yes. If you suspect your battery, replace it. But, since it’s less than 5 years old I would also have the charging system checked out. I shorted diode in the alternator can do this. Also, check for some load that is not turning off like it should. An ammeter on the battery with everything turned off should show a very low current draw. A stuck on glove box light, or something might be a problem.


Grr . . . F$*%&ing no edit feature . . .

I meant to say “a bad diode”


After a hot engine is shut off, the engine cooling fan will come on and run a few minuets, and, then shut off. Sometimes, the engine cooling cooling fan continues to run and drains the battery. After the engine has been shut off, at least an hour, go to the car and listen for the fan. If you hear it running, the fault is probably the fan relay is sticking. If this is the case, change the relay, and all will be brightness and happiness, again. ++++ me_art12