I recently put in a new battery since my 8 year old Optima finally died. Almost a month after the new battery (Advance Auto brand 51R) and after about 3 weeks of not driving the car, my battery is dead.

The only thing I think I have found so far is that the light near the ingition that illuminates your key will stay on. It seems that if I lock the door then close the door, the light will stay on. If I close the door then lock it using the key, the light will turn itself off after 15-20 seconds.

I have only the stock factory alarm and the alarm will arm either way I lock the car, but does anyone know why this would be happening?

It started right up with I jumped it on Friday when this happened, so later today I'll try to get a chance to try to start her up since it's been a few days and hopefully she won't be dead again.

Also I was thinking of buying one of those solar panels that plug into your cigarette lighter to try to prevent this from happening again. Would that be sufficient to keep the battery charged?

 

Since this just happened to me last week, check and make sure the TNS relay isn't turning itself back on after some period of time. I'm not the first person this has happened to, either. The TNS relay will kick back on after several minutes, which will turn on all your running lights and drain the battery. Try removing the TNS relay when you park and see if your battery stays charged. It's in the relay box under the hood in front/left of the intercooler.