Thread: DC-DC charger- which one?

Hi Mungus and you are correct but it is not likely that most D4 owners will ever notice ( UNDER NORMAL OPERATIONS ) that their battery has been discharged down to 12.2v.

The procedure in the info you posted up, will take about 30 minutes of continuos driving to discharge the battery by 25%.

Or as stated in the info,

Originally Posted by Mungus

NOTE:If the vehicle is only driven for short periods the charging process could takea number of days to complete.

NOTE, the battery will not be at 12.2v for 30 minutes. It will most likely only be there for less that a few seconds to maybe a minute.

The point is, the battery does not remain at 12.2v for any length of time.

This is not what is occurring in the D4s that are having problems. Their operating voltage level remains at a constant 12.2v, and this is a major problem when it happens.

I have been observing the voltage for the past several months.


It only drops down to 12.2v after the battery has been well charged and then if goes down to 12.2v when cruising or going up a hill. If you cruise constantly (without taking your foot of the accelerator) it can stay at 12.2v for quite a while. I have seen it last for at least 10 minutes while cruising on the M7. It will then jump up to 12.5v even though you are sill cruising.


As soon as you coast or go down a hill the voltage will jump up to anywhere between 13.1 and 14.9.


It is not completely consistent. I do the same trip everyday and I see 12.2v several times a day but not always under exactly the same circumstances. It never happens when coasting.


I wish I could taking a video so I can show you


Can anyone publish the content of the TSB. I don't know how to get TSB data.

Originally Posted by RoverLander

I wish I could taking a video so I can show you

Hi Peter and you don't have to take a video to convince me that your voltage readings indicate that your alternator is operating at 12.2v.

The point is, if the reading is being taken from your battery terminals, then you have a problem that, if not fixed, will stuff your battery.

If the voltage reading is being taken somewhere other than at the battery's terminals, then the readings themselves are irrelevant, because of the effects of voltage drop that will commonly occur on any circuit running through your vehicle ( or in any vehicle ).

Furthermore, as has already been stated, running a DC/DC device off a battery that is not being charged at the correct voltage, will just help to shorten the battery's life span.

RoverLander, you are getting voltages better than mine when the car decides to charge, and my D4 is an MY12, which according to LR Southerns is performing perfectly.

The highest I have seen is 14.2 averaging much lower in the low to mid 13's when she charges.

Brett....

Originally Posted by discotwinturbo

The highest I have seen is 14.2 averaging much lower in the low to mid 13's when she charges.

Brett....

Hi Brett, and what is your lowest operating voltages?

EDIT:- Also Brett, where do you get your voltage measurements from?

Originally Posted by RoverLander

Can anyone publish the content of the TSB. I don't know how to get TSB data.

An extract from TSB LTB00667v2. A subscription to Topix is well worth the coin IMO.

Only refer to the electronic version of this TechnicalBulletin in TOPIx.

SECTION:414-00

Battery WarningMessage Displayed On The Instrument Cluster

AFFECTEDVEHICLE RANGE:

Discovery 4 / LR4 (LA)

Model Year:
2014
VIN:
698741-726591

CONDITIONSUMMARY:

NOTE: If the DTC B1404-13 'charging system opencircuit' and or B1479-72 power supply distribution box actuator stuck open' isnot stored in the GateWay module, continue with SDD diagnostics with referenceto TOPIx workshop manual.

Situation: A customer may report a concern thatthe battery warning lamp/battery warning message intermittently displays on theinstrument cluster or the Eco stop start may not function.

This version has been issued for a change to theAffected Vehicle Range, Section and Condition Summary.

Cause: GateWay Module (GWM) software issues. Suggested Customer Concern Code MU3.

Action: Should a customer express concern,follow the Service Instruction outlined below.

Originally Posted by drivesafe

Hi Brett, and what is your lowest operating voltages? EDIT:- Also Brett, where do you get your voltage measurements from?

12.4....mostly hovered around 12.9. The app I use allows me to record the whole time while it was running, so I could then watch each period of recording each evening.

I use the OBD port. I don't get the low voltage warning on the display that others seem to have.

Brett...

Originally Posted by Mungus

NOTE: If the DTC B1404-13 'charging system opencircuit' and or B1479-72 power supply distribution box actuator stuck open' isnot stored in the GateWay module, continue with SDD diagnostics with referenceto TOPIx workshop manual.

OK now this is something that needs more info.

I only have a basic knowledge of the ECO STOP/START system, but is the reference to "charging system is open circuit" talking about the cranking battery, which I suspect it is not, or is it referring to the STOP/START battery.

NOTE, one of the ways to deactivate the ECO STOP/START function, is to disconnect the negative lead on the STOP/START battery.

This is literally creating an OPEN CIRCUIT situation, which is virtually the same as what is started the Land Rover documentation.

Again, RoverLander, can you post up where you are taking your voltage readings from.

As above, if they are not at the battery, they are irrelevant, and if they are at the battery, then according to Land Rovers own Documentation, courtesy of Mungus, your D4's battery voltage is too low ( not normal ).