Advice
 

I have a 2004 Black 9,000 Miles love it just a few comments: I checked the battery last week thinking itm was ma no maintenance battery. Guess what it has 6 removable caps and the thing was real low on water i had to fill all 6 cells. Do all the cars have this type battery?? Also i have noticed in the A.M when I start the car frequently I turn the key and absolutely nothing happens. I turn the key off and restart and it is fine. Sometimes this will happen twice but I always get it to start any idea??

The OEM battery in the US RX-8 does have removable caps, but I'm not sure if it is considered a "maintenance-free" battery. The shop manual is not clear about that. All it says is that the caps should be removed when charging the battery. I would guess that it is not a maintenance-free battery. If you are adding fluid to the battery make sure you use distilled water and don't fill it to the top'

Also, the OEM battery in the US cars is a bit on the weak side and if you are having trouble starting the car, take it to your dealer and ask that they replace the battery with the new replacement battery that Mazda is recommending--the Interstate MTP-35. I am replacing the OEM battery in my '8 with the MTP-35 at my own expense just in case the car floods and I need extra cranking power to get it going.

Get a better battery. I replaced mine even though it worked fine. Just bothered me that the OEM battery might not have the power to let me re-start if that flooded engine time ever comes. Its worth the money for the confidence factor.

Actually, according to the Interstate web site data, the MTP-35 weighs 40 lbs. Have you weighed the OEM battery? I would be interested in the true weight of the OEM. The literature I found on the OEM Yuasa battery installed in the US cars indicates it weighs 13.8 kg (~30 lbs.) with acid. I don't consider the 10 lbs extra weight significant. But then again, I know there are owners who are working very hard to eliminate ounces. So whatever floats your boat I guess. :)

Buy a better maintenance free battery. It it weighs more and that bothers you, go on a diet. Or if you don't weigh so much, think about how much less the gross weight of your car is compared to overweight drivers. Or temporally lose weight in your car by never filling up the gas tank.