ND battery under-spec'd?

[Mr Morlock]

What Luke has identified i.e. city driving short runs etc is exactly the data that car engineers use and cross reference to the specific car. Mazda choose a battery that suits the model i.e. a battery that meets life and usage and electrical demands for that vehicle- space and weight is often a criteria . I expect many owners just do short runs around town and drive once a week and some people will park outside in cold areas as well. USA is a big market and weather conditions can be horrific. You could not make a volume car with a battery life of 2-3 weeks and I think the ND should still fire up after 4 weeks. Mazda needs to give RBH a proper report not a fob off.

[bruce]

Just replace the battery with one from a dealer.
If it goes flat, I'd ask them to refund and fix the problem. If it doesn't go flat, bingo, dud battery.
Easy.

[RBH58]

In my experience I wouldn't expect any more than 3 weeks in any car over Cold Winter months.
More than that should be considered a bonus.
2 weeks does seem short but then again my NB literally just cranked over tonight after sitting for 2 cold weeks. I even took the jump starter with me just in case as all I was doing was heading down the road to get fuel.

You say you live in an apartment in Melbourne.
Please elaborate on how you use the car as you have so far just stated that it has gone flat quickly and is not meeting your expectations.
Stating the battery is under sized by Mazda after reading some American complaints on miata.net is not a solution and will honestly get you nowhere with Mazda in Australia.

You either have a crook battery, some sort of electrical drain or have bad driving conditions.
Mazda has checked your car at least so you have a record to go back on under warranty if it is a fault.

However since you are in the city I would take a guess you are driving in heavier traffic, so more idling, and possibly shorter trips??? These conditions would kill a battery much quicker as it never fully charges. If it is not at full charge it will not be able to sit around as long.

Like I said please elaborate, especially if you can remember your last couple of trips before leaving the car to sit around.

I live in Port Melbourne and commute to Rowville most days. This is an 80km round trip, most of it at 80-100kph. Last trip before the 2 weeks period where the battery died was one of these runs. If that's not enough to keep the battery charged, I don't know what is.

I've been leaving my previous cars undriven for 2-3 weeks regularly for the last 13 years. Never an issue with them starting first time. If you don't expect 3 weeks battery life from a modern vehicle then your expectations are laughably low. I'm sure you'd be in the minority.

The dealer tested everything and said it was all okay. We'll see because I'm away for 14 days from Saturday. If it dies again I won't be accepting it as "to be expected".

[Red_Bullet]

Has the battery been load tested? Yes/No? Gotta start at the beginning.

[bruce]

A number of people have asked him that question...

[RBH58]

Has the battery been load tested? Yes/No? Gotta start at the beginning.

The dealership said the battery was fine. Yes they tested it and they tested for alternator performance and resting drain. They said it was all "in spec". I'm open minded but 2 weeks idle draining the battery is not acceptable whatever the reason.

[Red_Bullet]

Ok..maybe light weight car, light weight battery. If a designer is trimming weight the battery would be a low cost place to start.

[RBH58]

Ok..maybe light weight car, light weight battery. If a designer is trimming weight the battery would be a low cost place to start.

Sure.....and that's why I'm suspicious that the battery has become part of the "gram strategy" and, for a 21st century car with 21st century features, is marginal in capability for the systems it's expected to run.

[Luke]

I live in Port Melbourne and commute to Rowville most days. This is an 80km round trip, most of it at 80-100kph. Last trip before the 2 weeks period where the battery died was one of these runs. If that's not enough to keep the battery charged, I don't know what is.

I've been leaving my previous cars undriven for 2-3 weeks regularly for the last 13 years. Never an issue with them starting first time. If you don't expect 3 weeks battery life from a modern vehicle then your expectations are laughably low. I'm sure you'd be in the minority.

The dealer tested everything and said it was all okay. We'll see because I'm away for 14 days from Saturday. If it dies again I won't be accepting it as "to be expected".

Hmm now that you have elaborated on the conditions, I do find it strange the car was completely dead after 16 days as that should have been a decent charge from those conditions.
I would expect it to at least power the lights, fan or radio.
Kicking it over is a different story as that requires a lot of current so would not guarantee it.
Unless it was drained by something silly like an interior light.

If the dealer reckon their tests showed normal drain I couldn't see it being anything other than a Dud battery or something was still on for everything in the car to be dead.
The ultimate test will be to see what happens when you leave it again on your next trip.

And seriously if you get 3 weeks out of a battery from a modern car sitting around that is pretty good.
All the articles I'm reading on the web seem to indicate 2-4 weeks is the norm depending on the car for modern cars due to the extra draw of all the electronics you realistically don't need being powered whilst sitting doing nothing.
Like I said before I only have ever really gotten about 3 weeks out of 3 previous cars. The latest one I have literally just kicked over at 4 weeks of sitting but that is a Diesel with an enormous battery.
You bought a light weight sports car that is trying to save weight. You can't expect to have a big heavy battery in it so expect it to die sooner than other cars.

I don't have low expectations. I'm happy to be in the minority. I'm used to gear not doing as expected as I'm a tech guy and that is the norm to me.
Especially new gear that has been out for a short time, ie the RF.
Unfortunately early adopters always pay the most and are more likely to get burnt.
Expect the unexpected.

[RBH58]

I think having to trickle charge of disconnect a battery for 2 weeks is unacceptable. My BRZ lasted 3-4 weeks on several occasions. So did my Megane RS. So did my Volvo C30 T5. So did my 147GTA. So did my TT. So did my NC. All modern cars with central locking and stuff that will provide a constant drain.

[davekmoore]

As in the previous post, a few short drives with heated rear window, heater blower, and lots of other electrical stuff running, could easily leave the battery less charged than before those drives. Add to that the fact that modern cars do use some battery power when parked, and that there is no power socket from which you can trickle charge it when it's left for a while, you might indeed have an issue, even with a perfect OEM battery.

Do you have a way of measuring the battery's condition?

Is there any daylight where you park?

Have you asked your dealer to supply you with a replacement battery while they do whatever tests they like on the original one (because if that solved it, that would point to a battery fault rather than a car fault)? If that solves it, they should let you keep the replacement and they should send the original back to Mazda as a warranty claim.

Or you could bite the bullet and buy your own replacement battery as high a spec as possible. If that doesn't solve everything then an issue remains either with the car or how you have to use the car. So the car goes back the the dealer for investigation (ask for a loan car while they do it as that will usually speed up your own car being fixed).

Meanwhile, keep your OEM battery, and a set of jump leads, and a charger, just in case there is no fix for how you have to use the car. This latter might sound defeatist, but it's more convenient than not being able to start your car.

[Mr Morlock]

Boy -some people don't seem to understand anything about design and engineering. The MX-5 is quite typical of any modern car and probably equivalent to many of the small cars. The problems will have nothing to do with how the thing is dríven i.e. many vehicles are just dríven a few KLMs to the shop everyday without problems- RBH uses it normally anyway. The designers / engineers figure that in. In a modern world people go on holidays for a month and they get in their cars and start them- i.e. thats normal behaviour- people go on holidays. If the interior light is left on or the door is ajar etc then the batts flat- no mystery.

Batteries have a guarantee on life of "X" and that means its supposed to last that long and thats pretty well the way that they are manufactured as well.The battery maker expects the car maker to choose the right spec battery. Its not hard to get a battery checked by an auto elect and no $ charge- you have to put the batt under load.

The existing battery may well be a dud- the load test should get a pointer. In engineering co's they do things like 8D problem solving and one of the first things to do is actually try and define the root cause or causes- the battery is just one of them. I am not sure Mazda have done this properly.

If ultimately its found the thing is under designed I wonder if its possible, probably not ,to use another battery. This is not exactly good publicity for this car which has already been put on a diet including its usable space.

[RBH58]

I think my usage is normal, and for having a well charged battery all of the time, maybe even optimal.

The dealership said everything was within spec. They have no reason to lie to me. Actually, my wife is the State HR Manager for the group (AHG Holdings) that the dealership belongs to, and she knows everyone that works there personally. So I'm 100% certain I'm not getting a snow job.

I will see what happens in 2 weeks time when I get back from my next trip. If it's dead again I'll be escalating the issue.

[JBT]

Look forward to hearing the outcome either way.

[OMY005]

Anyone else experiencing this?

My ND (not RF) can sit for 2-3 weeks with no issues.

Andrew.

I'll say it again, mine has no issues. But it does matter where you leave your key transponder, check out the big forum.

Was the battery drain test done at the dealer with the transponder in the car or a large distance away?

Andrew.