I was out of town on business for 3-1/2 months. My year-old RX-8 was under wraps. When I returned, the battery was dead. I mean DEAD. I talked to the Mazda service rep who told me that new cars these days have a "parasitic drain" due to all the on-board electronics and that I should install a battery terminal disconnect switch if I am going to leave the car parked for over a month. I stopped at several auto parts stores and did an internet search, all with no luck. Has anyone else had a dead battery problem after the car has not run for a month or more? Anyone have a line on a battery terminal shut-off switch?

 

If you go out of town often I would suggest a trickel charger so your car will be ready to go when you get back.

 

yes mine will kill the battery in about a week

trickel charge

 

Great. Thanks! What's a trickle charge? I have an old battery charger - do I leave it connected to the RX-8's battery the whole time I am gone? Or is this a new device I need to obtain?

 

Well if you can park the car outside this is an easy fix, or run the charger out a window.
http://www.baproducts.com/rpgt0417.htm

Or something like this if indoors
http://www.redhillgeneralstore.com/A53583.htm
http://www.carcareonline.com/detail....oduct_id=29204

A battery disconnect switch looks something like this
http://www.prostreetonline.com/buy/s...ry_disconnect/

 

What the dealer told you is about right. Being involved in the automotive industry, there is a test that almost all the manufacturers use called "stand by mode" or other simmilar names. Pretty much is to let a test vehicle to sit for 21 to 30 days outside and after that they will try to start the car without any assistance. During this period they will monitor the current draw by the PCM, radio and other parasitic loads. Again that also depends on the conditon of the battery and the enviroment. The mentioned trickle charges will work. However, If I go for a business trip longer than a month, I rather disconnect the battery. Upon returning it I will give it a few hours of charge before starting the vehicle.

 

This is the device that I use for those times that I leave the car at the airport for a week (alas). It's cheap too: http://www.autosportcatalog.com/index.cfm?fa=p&pid=53 ... "the green ****." It's weird, but after a week, my battery is fine, even with the **** in (tried it at home). Aside from that, I like the peace of mind.

If you want the "RX-8" of battery protection devices ( ;-) ) , then check out: http://www.autosportcatalog.com/index.cfm?fa=p&pid=141 .

 

very good eye.. I am going to carry that stuff.. All 3 the battery tneder is goo d.. The Green **** is a cool idea and this is cool to !
http://www.autosportcatalog.com/index.cfm?fa=p&pid=52

 

Wow! What a selection to choose from. I normally park my 8 in a carport with the car cover over it. The solar trickle-charger would not work for me. I could use the ac trickle charger, but that would only work when I am home...not if I have to leave it at an airport or such. The "green ****" would be a good solution, with the 9v battery memory maintainer plugged in to keep all the settings. My question is: doesn't the cigarette lighter in the 8 turn off with the ignition? If so, would the 9v battery device still work with the ignition off? Has anyone used the autosport Memory Maintainer in their RX-8??

 

Seeing as how the parisitic drain will pull down a full-sized car battery, I'm not sure how a 9v dry cell could hold out for a month...?

 

yep, that would be an issue.. but really we need to get mazda to fix this..
You need to remove your trunk light and make sure its not in the Trunk lighting or release mech. On my car it is the ECU .. and nothing elses ..

And yes after 3 days of sitting my Red Top will be dead !
now it sits with my battery maintainer on all the time ..

 

After considerable web-searching and talking to hardware and auto-supply stores, it seems that most modern vehicles do drain the battery to maintain settings in all the onboard electronics. This is not a "problem" in the sense that anything is wrong, just a short-coming in the design of our modern, gee-whiz automotive gadgetry. The solution I have opted for is a Shumacher automatic charger. The Shumacher manual trickle-charger I initially ordered turned out to require momnitoring, something I cannot do when I am out of town for extended periods. The model I will use is Schumacher SE-1562A. It shuts itself off when the battery is fully charged and kicks in again when the battery starts to get low. I really don't like the idea of having to reset the clock and radio buttons every time I come home, which the disconnect switch will require. Thanks for all the suggestions.

 

Does the "Green ****" fit in the 8's battery compartment? Kind of a pain to get into that box every time I leave town. Hrm.

 

Don't know about the Green **** fitting. Huhsler says (above) that he uses it - I assume in an RX-8. But you would have to reset the radio stations and the other electronic monitoring devices may have to be reset - tire pressure sensor, ABS, stability control, ???

 

I've had the same problem w/ mine on a regular basis until I put the trickle charger on it (it doesn't get out as much as it used to in sunny TX). One thing the dealer told me to do was to pull the "room" fuse on the car. You'll lose your radio stations though (why I put a trickle charger on it)...

 

My RX-8 sat for 7 weeks outside, yet it started right up without incident.

I use the green **** disconnect on my older cars, which works well for what they were designed for. Also own a solar trickle charger, as the New Bettle I use to have would drain the battery after 1 week of non-use.

But my RX-8 did great all by itself during November & December.

 

Mine sat for about 3 days and died. It turns out that the trunk light was on. That is not an exciting design. I charged it up and it was dead in a week but the trunk light wasn’t on. I charged it up again and it sat 2 weeks and started fine. Go figure. I figured that I killed it when it was dead at 0 degrees. I’m going to try to get a new one from Mazda.

I design aftermarket products for cars and I have never heard of parasitic loads draining batteries in a matter of weeks. I always shoot for more like 6 months to a year. Microprocessors are drawing less & less power so things should be better than they were 10 years ago.

 

I've had problems that sound real similar. I let the car sit for about a week and a half in the cold, under a cover. Went to go start it and all I could hear was clicking, so I knew it was a battery issue. So I jumped it, then drove it for maybe 45 minutes or an hour, then put her to bed. Went to go start it the next day, it started up fine, but I got a check engine light to come on and I couldn't go higher than 2000 RPM in first gear, no matter how much I pushed on the gas. I managed to get back to my driveway and then calmed down a bit before calling the roadside assistance. The guy got there and we tried the car again and it worked fine. The check engine light was still on but I could at least drive it.

Later on, I was told the same thing that you have all been saying here, that the car's electronics take energy from the battery even when the car is at rest, which I wasn't aware of. Another interesting thing I learned is that when jumping the car, you want to have a few or all of your electronics in the car turned ON. This seemed counter-intuitive to me, but I was told that it keeps the car from seeing a spike in voltage when you jump it. I'm pretty sure that's what happened to me, I sent a spike into the system and an engine sensor alarm got fouled up and that was causing my engine run problems. So, turn stuff on when you jump.

Also, if your battery does die and you let it idle for 15 minutes or so (like I used to do with my older cars) to have the alternater charge it back up, you have to be careful. I'm pretty sure the stock alternator puts out 14.5 amps, and I know my tail lights alone use 6 amps and I'm sure the xenon headlights and other gadgets use quite a bit too. So, that's another thing to consider.

For those of you that read this and already knew all of it, sorry to waste your time. I learned a bit here and wanted to share it.

 

Oops, that was for me!

I was not able to install the Green **** per the instructions, due to the engine cover and other things around the battery. I ended up using hot glue to mount it on the front of the battery itself, via a velcro plate. It BARELY fits and YES pulling the **** does require that I remove both covers (the other one sort of pins the **** in...if you can picture it...), take it off, then put them back on. Ironically, I've only had to use it once since I changed jobs. Ah well.

 

If it only puts out 14.5A at idle and the headlights and tail lights were on then the battery would die even with the car running at idle so it must be more than that. Most modern alternators put out close to 100A (lower at idle) but they probably did skimp a little to keep the weight down in this car.

As far as turning all your electronics on when you jump start. I'd say that is bad information too. All the current to start the car needs to come through the jumper cables. If you turn everything else on you will be adding current which creates a voltage drop over the cables. Your dead battery is also creating a voltage drop and then when the starter kicks in there is another. If you are jumping it from another car it's voltage regulator is going to hold the voltage constant so I don't know where the spike would come from. You may have been misinformed.

 

My local auto parts store stocks Schumacher chargers.

Dumb questions ...
1. do I need a six or 12 volt charger?

2. Is the eights battery a:
A. conventional or low maintenance battery
or
B. maintenance free or deep cycle battery

Thanks in advance,
Oranje

 

Oranje: The RX-8 battery is 12v, so you need a 12v charger. I believe the automatic one I have ordered is both 6v and 12v.

As to the maintenance issue, the 6 caps do not pop off easily (you have to screw them out) so I don't think that it is "conventional", but since it does not appear to be sealed, I also do not think that it is "maintenance free". I very much doubt Mazda put a deep-cycle in, so I'm guessing that it is "low maintenance". I am supposed to receive my charger by the end of the week (around 1/12/05) & I will add a note as to how it appears to function.

 

Thanks for the follow-up BB.

Oranje

 

when i left for london for 2 months last year, disconnected the +ve terminal, came back, hook it up (with 10mm spanner), the 8 started straight away, but read the manual, you will have to turn the wheel full lock left and right after that..... (cant remember what it said exactly :p ).
the 8 has been in the workshop for over 4 weeks, did the same, and started it up yesterday, no prob

 

Happened to me once, when I went on deployment for 3 months. The next time I didn't arm the alarm, and it started right up when I got back.