Battery maintenance is critical even if located in an awkward place. How do you KNOW that the cable connections are NOT all corroded, but clean and secure as they should be?
Also for everyone's benefit, you not only need volts but AMPs as well to operate the electricals of any car. That is why ALL batteries have a CA and CCA(crank amps/Cold crank amps rating). A load test determines how much is available in the battery and can also detect a dying cell.
Go to a auto parts store like Autozone or Advance auto, they can do this test for free, and they will do it from the jumper posts. BUT if you have corrosion /connector problems it WILL show as a bad battery. IF you still have the original battery in this car chances are it is a dying battery, and if you are unwilling to physically check it, you are doing yourself and car a disservice. OR spend the money and have a repair shop do it for you.

 

"Thanks..I did check for parasitic draw and I could not find any major problem...with door closed and everything off its only 40 mAmp draw ...if I open the door its about 150 mAmp and if I hook phone charger in to cigarette lighter port ...its 50 mAmp..which I believe its normal...so can I can I think something wrong with battery that it does not hold the charge?"
Typical draw "sleeping" should be more like 25 mAmp not 40.
Interior light operation described is "normal" Diminishing ground dims lights off over a longer period of time, unless the car is started.
Batteries over 5 years old should be replaced as they age, modern electronics get wacky as battery internal resistance changes.
Load Test in place tells most of the story. Conductance testing directly on the battery posts tell the whole story.