i love the rx8 but have had problems with the battery dying. the dealer told me that the electronics run the juice down fast. since i drive it on special occasions, i sort of understand that but have had the battery die 3-4 days after driving so not sure about that. should i put a trickle charger on it?

 

battery shouldn't be dying in just 3-4 days. I know I'd left my car sitting for 2 weeks at a time and it still fired up.
One common issue is the trunk light. If you accidentally pop the trunk (can happen if the keys are in your pocket) that darn light WILL stay on the whole time and drain the battery.

Is this your OEM battery?
If so, how long have you had it? Where do you live? Heat can kill batteries quite quickly.
Have you checked the water level in the battery?

You could always go down to an auto parts store such as AutoZone and have them test it. If the battery is dying, I'd recommend something with more cranking power such as an Optima Red Top. I have a stereo system and subwoofers in my car so I opted for the Yellow Top since it's a deep cycle.

 

I agree with jedi. I have the red top since my car use to do the same thing after a couple days, and it's been almost a year since I had the red top and no problems at all. I do hate that trunk button on the key chain. I've had it kill my battery before since the trunk doesn't pop up to high, and you don't really notice it.

 

Yep, another member here who has drained the battery with the inadvertant trunk ajar/light. And another vote for an Optima Red Top, all other things being equal.

Of course your alternator may not be putting out the ~14 volt range to properly charge the battery, but cross that bridge after you've eliminated the battery capacity variable.

 

+1 to accidental trunk pop. Never killed my battery though. I watch for the parking light flash when I lock my doors. If no flash, then something is ajar. I have now disabled the trunk pop button with the switch in the glove box. Key only now.

If everything in your car is stock, then you have a problem. I've let my car sit for weeks with the original 3+ year old battery and had zero issues with it firing right up when I need it. I don't think buying a new/better battery will do a damn thing for you. There is no reason why you should be running through multiple batteries like that. Ask the dealer to check for a parasitic draw. This will also reveal lights that may stay on or anything like that.

 

Thanks to everyone for all of the useful information. learned a lot!