I went out the car the other day and turn the key to accessory to get a idea where a lake was located on the nav. I didn't have the car on for more than 5-10 min. The next day I went out to start it and the battery was dead. This happened once before when I noticed I left the light on for about a 1/2 hour. Has anyone else had this problem with the battery and if so is there a better battery available? Thanks

 

glide....Sounds like this could lead to more problems, the OEM battery is known to be weak, Mazda is replacing the OEM with a better one, Check to see if your battery is still covered.

 

If you are already having problems, I would suggest you have your battery replaced with the newer replacement battery. For the money it costs, it will probably save you a lot of trouble in the long run (ie. avoiding floods, etc.).

 

Optima Yellow-Top, model D35

 

Discussed in the 'Tech Garage' forum already.

Optima Group 35R (reversed posts), red top. You DO need the height adaptor for it to fit in the RX-8.

http://www.batteriesareus.com/shop/p...products_id=61

 

Batteries are rated in RC which means number of minutes to go from full charge to 10,5 volts
(which is dead as far as starting a car is concerned). The OEM batt is about 80 Mazda is replacing a lot of 'em with a MTP 35 which is RC of 100. The Optima yellow top is about 120.

What rc means is the number of minutes to go flat to 10.5 v when a constant 25 amp is being drawn from it.

The RX 8 has lots of complex circuitry and some of the devices draw excessive current when th car is at rest. The drain should not be more than 0.020 amps according to the manual.

My car draws about 0.300 amps at rest and that causes a dead battery in a little over a week Mazda replaced my OEM batt with a MTP 35 RC 100 and that's a bit better than the OEM.

The Optima will last longer but thats not the problem. The problem is excessive drain. If you pull the 15a "Room" fuse the drain goes down to under 20ma and solves the problem.

The bad news is that the clock resets and the radio stations are lost when you put the fuse back.

I'm convinced there's something basic wrong because SCO reports his car is draining at 0.020a.

Please advise of any other ideas or solutions or comments.

prbeswick prb@beswick.com

 

Batteries are rated in RC which means number of minutes to go from full charge to 10,5 volts
(which is dead as far as starting a car is concerned). The OEM batt is about 80 Mazda is replacing a lot of 'em with a MTP 35 which is RC of 100. The Optima yellow top is about 120.

What rc means is the number of minutes to go flat to 10.5 v when a constant 25 amp is being drawn from it.

The RX 8 has lots of complex circuitry and some of the devices draw excessive current when th car is at rest. The drain should not be more than 0.020 amps according to the manual.

My car draws about 0.300 amps at rest and that causes a dead battery in a little over a week Mazda replaced my OEM batt with a MTP 35 RC 100 and that's a bit better than the OEM.

The Optima will last longer but thats not the problem. The problem is excessive drain. If you pull the 15a "Room" fuse the drain goes down to under 20ma and solves the problem. The room fuse is the bottom one in the LF door jam.

The bad news is that the clock resets and the radio stations are lost when you put the fuse back.

I'm convinced there's something basic wrong because SCO reports his car is draining at 0.020a.

Please advise of any other ideas or solutions or comments.

prbeswick prb@beswick.com
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