XSeries-forum

Ok, so last night I set the aux heater to come on early to defrost the car before I set off on a journey early this morning.

This morning I come out and the battery is flat. This happened about 3 months ago too but assumed the lights had been left on or something

The battery is Bosch Silver S5 100 019 and is 3 years old.

I previously had a flat battery on a couple of occasions but I know Mrs Smee had left the lights on. Nevertheless, I had my local Indy do a battery drop test and test for parasitic drain. Battery came back healthy and nothing found on parasitic drain

Does anyone have any suggestions as to what/where to to look to find root cause. I don't mind going out and getting a new battery but only if I know that that is the issue

Thanks
Smee

I'd check to see if the car is going to sleep with the Aux heater programmed to come on.  Was it totally dead or just a non starter? Very annoying battery drains.  >:( 

near enough totally dead - enough to get ignition lights on but just the click when you try to turn over

Yes I will try what you suggest later.

If it isn't going to sleep what does that mean?

And if it is going to sleep what does that mean?

Thanks
Smee

You can tell when the car goes to sleep, the Orange light at the side of the gear selector goes out, I think it takes about 15 mins from locking the car. When the car is awake, usually when the car is unlocked with the fob, a few modules are powered up.

No Sorry I wasn't clear.

Under normal conditions it usually goes to sleep in 16 mins - will test later with aux heating on

I know how to check whether it is or isn't asleep, what I mean is what will that tell us regarding the aux heater/battery?

Smee

ok, so Ive done the test - set the aux heater timer to come on then locked and left the car. It went to sleep as normal at around a little over 16 minutes.

So what next ?

Smee

Might be a fault with the Aux Heater itself.  It is supposed to shut down as soon as the volts get below a certain point, which means they only run for about 15-20 mins.

If yours is ignoring that due to a sensor fault then it will run until the battery is flat.  This can happen if it's a modded rather than an OEM system.  Not sure why, but it may be that if the coding isn't right then the voltage cut-off doesn't enable correctly?

Richard

It's oem with no mods, not even a remote timer. Is the sensor readily available and easy to fit? How could I test it ?

Smee, as the battery is still under warranty I think my first port of call would be to get it replaced with a new one. It's not gonna cost you anything so it's a 'free shot' before you start spending money in other things - you may find this solves your aux heater problem.

Yes I had considered that. lets hope that a) the garage fitted the battery I specified and b) they've kept their paperwork for me to claim under the guarantee.

Smee

[quote="Smeeagain"]
Yes I had considered that. lets hope that a) the garage fitted the battery I specified and b) they've kept their paperwork for me to claim under the guarantee.

Smee
[/quote]

Yeah that's a good point, the problem I had was that I'd been given an 017 instead of an 019, and had a slightly lower spec - the aux heater seemed to punish and I came out, like you to a dead or close to, battery whenever I used the aux heater, this so I stopped using it. When the 017 packed in and I exchanged it for the correct 019 the aux heater has been fine. The exchange with ECP was painless too, they didn't even check that it was knackered.

Hope you get it sorted.

[quote="PhilT"]
[quote="Smeeagain"]
Yes I had considered that. lets hope that a) the garage fitted the battery I specified and b) they've kept their paperwork for me to claim under the guarantee.

Smee
[/quote]

Yeah that's a good point, the problem I had was that I'd been given an 017 instead of an 019, and had a slightly lower spec - the aux heater seemed to punish and I came out, like you to a dead or close to, battery whenever I used the aux heater, this so I stopped using it. When the 017 packed in and I exchanged it for the correct 019 the aux heater has been fine. The exchange with ECP was painless too, they didn't even check that it was knackered.

Hope you get it sorted.
[/quote]e

The last point is the potential flaw in the logic - if the supplier does check it and it is fine then I'm back to square one so still need to find the route cause
Smee

Does it stay charged if you don't use Aux Heating?  If so then there is nothing wrong with the battery.  The fault has to be connected with the use of Aux Heating.  If it's OEM then do you have the key fob for it?  The OEM version did come with one to turn it on and off.

The only way you can check it is to put a meter on the battery and run the Aux Heating.  The guide for it says it will cut out at 10.5V +/-0.3V.  That voltage is far too low as that equates to a fully discharged battery so there ought to be a higher setting used for the X5.  If the unit is ignoring it and running on, then you WILL get a flat battery.  That makes the unit useless.

There is a Service Manual here.

Richard

Yes it stays charged and as posted previously the battery has been tested by local Indy and given the all clear. I would doubt they are going to agree to return the battery to their supplier on that basis

Agree that the voltage level is too low at 10.5V +/- 0.3V and thanks for the manual. at 10.5 v the car wouldnt start anyway so I don't see at what voltage the unit should stop draining the battery as it cant be at 10.5V , there must be another voltage level (ie the 10.5 v is presumably the operating voltage required)

And no although it may be OEM I didn't get any other key other than the two ignition keys, perhaps because I bought the car second hand and that key hasn't found its way to me

So when you say the unit is then useless do you mean it cant be repaired?
Smee

Not at all.  It should be repairable, but given what you need it for and the fact it kills the battery when you try to use it properly, it doesn't make it a lot if use at present.

I would gave expected the cut-off to be nearer 11.5V +/-0.3V for safe operation.

Richard