2005 RX8 A/T, 70k miles, new engine with < 5k miles

Story:
I ran the car 2 days ago and it was perfectly fine. Didn't start it yesterday but I went to it and grabbed something I left inside. Until then all the electronics were fine.

Then I came to it today, and I cannot use the remote to unlock the door! I enter the car with the key, switch to ACC, and the dashboard is completely dark with only a very dim light showing the open door, and of cause all other things were not working.

Then I tried to jump start it. with the jump cable, all electron components started to work immediately. Then I switched the key to start, all I heard was some very weak and slow"click click click" coming from the starter(I guess), not the crank from the engine. the gauge needles started to jump everywhere. then the dashboard became dark again, after 1-2 seconds, it started to illuminate again, then the check engine light flashed couple times, but stopped eventually.

I tried many times but always the same result. My best guess would be the battery(I don't have any voltmeter at hand, I will borrow one and check it out tmr), but I don't know why the jump start didn't work at all, and don't know what was that "click click click", especially I am worried about the needles jumping up and down horribly, and the flashing engine light.

Wonder if anyone can give me some clues?

thanks a lot

 

Make sure the terminals are clean and tight. Then replace the battery.

 

what Easy said.
Sounds like the battery can't hold a charge.

 

Have the battery charged & load tested, then make sure the terminals are clean and tight as Easy suggested. Once you get a charged battery installed, check the "Dark Current" draw. Check the alternator charging rate after you get it started.

 

Well, thanks guys. I do know it could be the battery. Just wonder how can the battery be wonderfully fine the other day and become totally dead just after 24 hours? Is this normal?

I had my old car some battery issue. Usually even when the voltage was too low to start the car, the dashboard still illuminated. It took more than 1hr to drain the battery completely (until the dashboard wont come on). I don't know if a dark current can actually kill the battery so quickly

 

It can when it is excessive; for example, the trunk light staying on.