Hey all,

so I’ve got an optima red cap battery in my 09 sedan. Every now and then the car won’t start and I assume it’s because a light or something was left on. I have a battery charger in the car that I put on the battery and it’ll start right up.

however the charger shows me how much juice it has and when jumping others cars it’ll use up to 1/3 or 1/2 of the power in the power bank. When on my car it’ll use 1/100th of the power maybe and it’ll start.

got the battery tested and it tests good
starter and alternator are also good

so that got me thinking maybe it’s a loose terminal issue so I took off both the positive and negative and cleaned them thoroughly and replaced them. Still happens.

went to get my car inspected for state inspection and after about 30 min on the lift for the inspection they brought it down and it wouldn’t start. So they then jumped it and tested it and it still tests good. Checked the alternator and starter again and still good.

now it’s colder out where I live and once the cold front came in 3 days ago and it doesn’t start 90% of the time. I clamp on the portable jump starter, car uses barely a smidge of the power and starts right up each time without fail. Got the battery tested again after this happening consistently in the cold weather and it STILL tests as a good battery. Battery is only 2 years old. Starter and alternator checked again just incase and still good.

Car doesn’t throw any codes throughout all of this. Can’t seem to figure it out. And since it’s happening more in the cold weather it’s getting more annoying having to be out in the cold attaching a jump starter to give a tiny bump of charge to start the car nearly every time.

any ideas what I might be missing?

 

Wait for other replies ... but I had an issue with an Optima Red Top years ago. It lost its charge over a period when I wasn't driving the car and once it had been discharged it could not be revived. I can't explain how yours continues to "test good" but I'd recommend moving on to another battery.