Don't count out a battery as I have tested new batteries at work and found them to be defective right from Johnson Controls which builds batteries under a bunch of brand names. Also own Optima. So you may want to get it checked as you may not have any issues but got a defective battery.

Not saying it is just have seen it enough to bring it up.

Try jumping it when it is doing this and if if lights off then is that pesky little battery. Hey at least it would most likely be still covered under warranty.