D3 dual battery system can = air suspension problems

[drivesafe]

For those of us who now own or are considering buying a new D3 or Range Rover Sports and are planning to install a dual battery system, I have been doing some research on fitting a system to my D3 and have come across some interesting findings.

First and for most, the new high tech alternators on both the D3 and RRS have microprocessors that monitor a number of function as well as working in conjunction with other onboard computers to optimise power usage in these vehicles.

One of the most important stats is that because these vehicles are fitted with calcium batteries, the alternator can, if required, produce voltages as high as 15.7 volts ( that is NOT a typo ) and as such, fitting an auxiliary battery other than another calcium battery will most likely mean a shorter operating life span for the auxiliary battery.

Another more obvious consequence of not fitting the right Dual Battery set up can mean problems can occurr with air suspension systems in these vehicles.

Contrary to what it may sound like, the electronics in these vehicles, specifically those assigned to looking after the vehicles electrical system is nothing short of amazing. For instance, the problems with air suspension system is not a fault but a self protection procedure.

Anyway the point I am raising is, if you are considering installing a Dual Battery System and can put it off for a few months, I would recommend doing so.

On the other hand, if you have a Dual Battery System installed and have had the air suspension appear to fail, before going back to the dealer first try disconnecting the Dual Battery System, thats the battery as well as the control device.

I will post more on this subject in the not to distant future, if anybody is interested.

Cheers

[p38arover]

I can believe that problems with the electronics can be caused by low voltage. The P38A gearbox ECU is particularly sensitive to voltage and will throw up error messages and then go into limp home mode.
Fortunately, one can usually clear them by doing a power down reset (turning the ignition off for a short time)

Ron

[drivesafe]

Hi Ron, what apparently goes on with the D3, to avoid the sort of thing you mentioned, in the D3 and RRS if the voltage starts to drop, the computer start shutting down non essential heavy current drawing devices. Things like the air suspension compressor, the heater, air conditioning, the sound system and so on, anything to keep the vehicle operating.

That’s a pretty incredible set up.

Cheers

[one_iota]

At work when the 'puters and the phones (because they are linked) stuff up we are required to call or email the central national "help desk" even though the IT guy who will fix it works in the office on the same floor.

Is there a help desk number on the dash?

[DEFENDERZOOK]

<span style="color:blue">if the confusers and the phone lines arent working....
how are you supposed to call or email for help......



thats why the IT guy is there on the same floor.....</span>

[Jamo]

Originally posted by drivesafe
Hi Ron, what apparently goes on with the D3, to avoid the sort of thing you mentioned, in the D3 and RRS if the voltage starts to drop, the computer start shutting down non essential heavy current drawing devices. Things like the air suspension compressor, the heater, air conditioning, the sound system and so on, anything to keep the vehicle operating.

That’s a pretty incredible set up.

Cheers

So if the voltage in the main battery starts to drop, it shuts down devices; or does it do it if the draw is too great whilst charging the aux battery.

I only ask because I have an aux battery and I have had my suspension stop working. :?: :?: :? :? :?

[drivesafe]

Hi jamo, I have read your posts and when I was told about the way the system works I immediately thought of your problems.

I can’t answer you with any certainty as I have passed on what I was told today while sourcing information about some new equipment we are developing.

The info I was given included, as I posted, as a means to try and find out if it is a fault or a protection routine being carried out buy the vehicles computer as a normal procedure, would be to disconnect your dual battery system first and see if that resolves the problem.

From what I can gather, and I’m still learning the ins and outs of the D3s electrical system in the areas that may effect the operation of our equipment and vice versa. Either a voltage drop and/or a large current draw can have an effect on a number of high current devices in the D3.

Sorry I can’t be more precise but as I pointed out above, I’m still learning about the system myself, but I will keep you posted.

Cheers

[drivesafe]

BTW, I mentioned that only a calcium battery could be used to avoid the battery ending up with a short life span.

Please note, I am NOT recommending you use a calcium battery for your auxiliary battery because, in my opinion, these types of batteries do not like being deep cycled or for that matter, they don’t like being discharged much below 15 to 20% of the full charge capacity so they won’t make good back up batteries.

Cheers

[Jamo]

Thanks drivesafe,

I know that my TR problems were to do with the faulty sensor, but I'm not so sure about the Suspensionfailure that I had at the same time.

I had been doing a lot of driving to that point so there should have been a full charger, but..

I had the fridge and satphone connected to the aux battery; and it was before I discovered the local blokes who installed the dual battery setup had wired it backwards!.

[Redback]

If this is the case Tim, then as the DII runs Calcium/Calcium wouldn't it be the same, and the DII alternator would put the same output (15.7volts) to the second battery.

Which means running a lead acid as the second battery in the DII or D3 is not good.

Baz.