Talk Morgan Forums Morgan Sports Cars Morgan Aero 8, 2012< Plus 8, SuperSports, Coupe & Aeromax S4 Battery Life

I asked about this at the factory when my aero was being serviced and I don't believe the factory know.

I think the issue is the ECU is not shutting down. The light stays on regardless of the doors being locked or unlocked.

On my BMW the ECU shuts down in stages with what I believe are to slowest to reboot items shutting down last. This way you can stop the car than then jump back in without the car shutting down completely. The car also starts booting up as soon as the doors are opened with the remote.

I suspect that whats happening is that the Morgan / BMW engine management system hasn't been designed / can't shut down fully and hence the light and what ever it indicates staying on are the battery draining. Simply bad design on the management system.

I did wonder what would happen if the bulb that stayed illuminated was removed would this overcome the problem????

I spoke to a BMW 535D owner recently- he complained of a permanently flat battery -BMW's response was he did too many short trips, even went flat after driving to Spain though! you are correct about ecu shutting down in stages - I think 535D took 4 hrs to close down completely.

Factory told me this was because Charles likes the lights on because it looks cool.
If they do power off after 5 minutes then fair enough I guess.

As Simon says there are a whole bunch of things that drain the battery, and it's a common issue on other cars.

Having said that my 10 year old BMW on it's original battery constantly says it is flat, but never ever actually does run out of juice. It never gets charged, and I regularly sit in it with the ignition off waiting to collect liz from the station with the stereo on and the heated seats blasting, plus it has alarms and various led's that never go off. C'est la vie I suppose..

We had the same Cobra Tracker fitted to the 911 and the AeroMax, in both cases because the insurance company insisted, and when we are away the 911 will stay charged for at least 5/6 weeks. The only thing that happens is the blipper will no longer operate the central-locking and you have to open it with the key. Then, starting it is not an issue.

The AeroMax will barely start after 7-days or so and I use a portable battery booster, but this will only start it if there is something left in the car battery itself as it does not have sufficient capacity to replace the battery.

As we can't use a CTEK conditioner in our garage, it really is an annoying issue and I hope someone can come up with a solution to the problem. MMC says it is the radio that is causing the problem, but the installer says they are not correct. HELP please!

I have a 530D, this is my third one and I've never had a battery issue. But then again the car does get used a hell of a lot.

I think the solution maybe to find a decent auto electrician and get an opinion, seven days does seem one hell of a short time for a battery to go, we have a number of vehicles with active tracking and left without being used the battery will last several weeks. This does suggest a more deep rooted problem

I think that you have hit the nail on the head. My understanding is that modern ecu's do exactly as you say and actively manage battery life by doing so. I am sure that the BMW boffins would sort it out in a couple of hours! Audi say that their battery management system means that a battery can never go flat. I never put the battery on the Aero 8 to the test and used a trickle charger routinely.

With my S4 all the dashboard switch lights stay on after locking for about 15 minutes. Then all but the interior light switch and bood lid switch stay on indefinitely i.e. they're still on when I next use the car.

I've taken to using the isolator switch under the bonnet on the basis that the car is garaged, won't start without power being re-introduced, at which point the immobiliser is operational again.

No doubt someone will tell me my logic doesn't work.

David

Brian,

I can believe that Tracker systems of whatever make are the cause of some battery problems.

My understanding is that Audi UK changed from Tracker to Cobra Trak for that very reason.

However think the problem with the Aero is more deep rooted along the lines of Asbo's theory. That MMC have suggested the radio is at fault is just typical! It would appear that MMC need to introduce active battery management into the software of the Aero.

Our ML63 was very prone to flattening it's battery but mainly because the phone cradle remained 'live' if a phone was left inserted. For that reason I invested in a SIP battery booster with the horsebox in mind too. Have yet to try it in anger but have been itching to do so! Of course the horsebox flattened it's battery at the end of year (courtesy of a very small helper) of course the booster was nowhere near!

Not sure how to help with your CTEK problem. If you have a window or skylight perhaps you could route a solar powered trickle charger. Perhaps some bright chap could put together a wind generator powered trickle charger?!

With kind regards,

Robert

911s have two modes - normal and deep sleep 9 (for want of a better word). In essence, the 911 monitors when the last it was used and when it gets to a certain number of days (7 iirc), it stops searching for a signal from the remotes (to save battery life) and goes into a deep sleep mode. By putting the key in the lock, the car wakes up and they you can either use the remote or the key to open the car.

It is a very clever way to set the car up but obviously the ECU system is far more complex than anything MMC have. As someone once said, Porsche, BMW, Mercedes, etc budget more for the design of a door handle than Morgan do for an entire new model. If plugging my car into a trickle charger is the price I have to pay for not driving it for 2-weeks but having something special to drive when I do, I'll pay that price.

However, lights that stay on when the car is locked and left should be looked into because that cannot be right.

Simon,

In retrospect I never got to find out if the start button went off when car was locked as on my S4 the car opened itself 30 seconds after locking the car!

Robert