Just registering another stat for the knowledge bank on our car's dodgy ignition engineering.

Car has been running fine. As late as last night started fine and I drove home without a problem. Locked up and no lights on overnight.

This morning, go out, unlock it, key in ignition, dull thud from engine bay then nothing. No starter motor response, no cranking, no warning light except red key. Then interior lights in roof started going on and off and locks sounded like they were clicking in the doors. Bloody thing sounded possessed.

Still nothing. No response from engine at all. After I gave up it wouldn't even lock remotely. Had to use key in door to turn the locks.

Diagnosis - the battery, she is kaput. Don't you love how there's no warning. You'd think for a car with a notorious habit of eating batteries long before other cars they would (retro)fit a low charge sensor or make it a replacement item every 20k or so.

Open to other suggestions as to cause of failure btw. Having a new battery fitted this arvo, so fingers crossed that fixes it.

 

Interesting... how old is your battery? and do you have after market alarm system?

My battery is nearly 6 years old (04 car with factory battery), and still hold 80% of charge according to my float charger.

I have two daily cars with after market alarm, every time I go oversea for 4-5 weeks, and when I come back all batteries are near dead, so I think the alarm is drawing quite a bit of power. So I didn't install alarm in my RX8 for this reason as I don't drive it enough, the result is that the battery is just as strong after 1.5 month sitting idle without the float charger.

 

Another possibility for the sudden death of the battery is there could be a short circuit in the wiring, electronic system etc... or alternator is bad and not charging.

 

Mines an 04 and I changed the battery last year after it died.

 

I had the exact same thing happen to me about 3 years ago in a supermarket carpark. Had to call in Marshall at around 8pm to get it fixed. There was no prior warning that this was going to happen.

I am looking for new batteries again as this time the car takes longer to crank than usual and each time I start the car it seems to be getting worse. I am looking at getting an Odyssey battery as it only weighs 10kg and is less than half the size of the stock battery.

skc

 

thanks for your responses guys.

no car alarm fitted. no drain at all except stock. the car doesn't do regular long trips but that's no different to any other car run around the suburbs and they don't go through batteries this quickly.

this is the 4th battery it's had in 6 years although in fairness the first battery was replaced before it died as part of the 'hard to start' "recall".

new battery fitted this arvo and it's starting and running fine now. guy who did it says he fits them to RX8s all the time and they're notorious for chewing through batteries.

I guess I can live with it as a design fault but I'd appreciate some sort of warning. I reckon Mazda should engineer and retrofit a charge sensor.

 

weird as I'm still on my first battery... nearly 6 years now and seems pretty strong, hope it's not gonna die on me this weekend :S

 

Correction...picked up my new battery and it only weighs 7kg and is 15x 15 x 6 cm in size. Great way to reduce weight of the car and help with cooling due to the extra space created.

skc

 

Dave, your symptoms pretty much mirror what happened to me last year. Fortunately, it happened at work, and I was able to call on an electronics engineer who is also a certified car nut. It was a collapsed cell. Could the mod. to improve cranking power result in higher current demand on the battery?

I think that the high engine compartment temperature in the RX-8 is at least partly responsible for the problem. My BMW125i has the battery located under the boot floor, to the rear of the axle. As well as improving weight distribution, it provides a cool environment. I just checked mine. It is cool, clean and dry. I don't how how feasible it would be as a mod. to move the battery into the boot of the RX-8, but it would most likely prolong battery life.

 

My original battery died a couple of years ago suddenly, however it was not a collapsed cell that caused it but a whole week of hot & humid days pushed it over the edge.

I don't believe it is just your car though Dave. Without running the numbers, I can say that battery sales from where I work are stronger on hot & humid days than any other type of day. This must be caused by the increased heat transfer caused by the increased moisture content of the air.

Engine @ Operating Temperature + high ambient temperature + >90% Humidity == Battery on death row.

 

My wife's Honda Civic had exactly the same thiing happen to it about a year ago, down to the door locks clicking and interior light flickering. It was the result of the battery dying suddenly overnight and we found that the problem was that the air conditioner actually stayed on over night after we turned the car off. There wasn't air coming through the cabin, but the motor stayed on (if that makes any sense?). Maybe your RX8 is experiencing something similar whereby an electrical component isn't switching itself off?

Labrat - I don't know how well relocating the battery to the boot will work in an RX8 if you want to keep it in a cooler place - I have noticed that the boot area can get quite warm after some driving. I'm sure it won't be as warm as the engine bay, but it's still not ideal IMO.

 

You're probably right - I remember it getting downright toasty in the boot of the 8!

 

I don't understand how you equate a dead battery with "dodgy ignition", since you don't state anything about prolonged difficult starting as a source of battery drain.

I don't see much evidence on the forums for "eating batteries", even on the early cars before the upgraded starter and battery specification. Something else is going on with your car....

 

No evidence of a collapsed cell in my car. As for the "mod. to improve cranking power", if you're referring to the 'hard to start' "recall" that involved new starter motor, plugs and battery, all of which were supposed to be able to cope with ignition demands. It may be that the battery can't cope longer term with the increased current demand, I wouldn't know.

Otherwise, I agree with Dr Gonzo about battery relocation - boot gets pretty hot too...and you're starting to mess with the 50/50 weight distribution...

 

I suppose we've had some hot humid days here recently but mine's not a daily, so it's not like it's being asked to cope with that kind of weather under startup load on a regular basis.

Interesting that there's more battery sales in that kind of weather though...

 

Slap a supercharger on it
Relocate battery to boot (Improving weight dist.)
fit after market muffler to replace that bit heat sink of a muffler

All problems solved ....

Next question

 

Hmmm, maybe but I couldn't see any sign of anything still on. The car was dead silent when I locked it up the night before and nothing heard at all when I got in that morning (early, so no background noise and I'm sensitive to the car's various noises, etc). I suppose it may be something silent draining the power but if that's the case why isn't it going through even more batteries???

I'll start getting into the habit of switching off a/c and radio before killing the engine and see if that makes a difference...

 

The car's an '04 and is yet to crack 65,000kms. Since new it's had 3 new batteries, 1 new set of coils, 6 new plugs and 4 new plug leads. So I was talking ignition generally, not just in relation to this particular battery replacement. I'm sorry but I call the need for those many parts dodgy.

I've read of a number of battery replacements in both the yank forum and our own Aussie forum and have had the problem informally confirmed by Mazda service guys and both of the last two battery replacement guys who came to my home. I appreciate it doesn't affect every car but there's more than enough smoke for there to be some fire on this issue.

Since you think I'm wrong, what's your theory? I'd love to solve it instead of forking out for a new battery every couple of years.

 

Hahaha, no. 1 isn't far away (April) and will speak to my installer about no. 2. I agree no. 3 helps but it still gets pretty hot in there...

 

I haven't seen an unusual number of posts on excessive battery problems, but I have seen several posts attesting to normal battery life.

Have you had a qualified shop check:

• the electrical system for parasitic drain, bad grounds, etc.?
• the charging system for over / under charging?

Since this is a 2004, have you had the starter & battery upgrades done per the TSB?

 

As posted above I have had the TSB upgrade - which was when battery no. 1 was replaced.

I will get an auto-electrician to check out the issues you mentioned. Thanks for the advice.

 

Well......make sure your battery air duct channel isn't blocked or you have the battery itself blocking it? I just changed my original battery on my Dec/05 and I didn't even really need to do so, but I wanted to try and Optima Redtop AGM. The spare Panasonic(OEM for us) is just sitting in the garage on a float charger. There really is an air duct channel that runs up into the battery tray for cooling.

 

Bad luck Dave you prob consider battery relocation.

 

Thanks for the tip. I'll get that checked out too...

 

Drive it more!

Come down and meet me for lunch one day!