Stop start battery failure cause?

[ClevelandLR4]

So does that mean software forgets about aux battery completely and let’s it die off once you disabled the start stop function?

 

[Fuji4]

No. It had the same problem before under warranty. Dealer replaced it once already.

 

[Michael Gain]

Maybe the isolator is shot? Not sure what land rover calls it, but it looks like a fancy isolator to me. The main battery cable crosses behind the engine and attaches to a "block" that has three terminals. Battery one, battery two, and I am guessing alternator or starter.

Attached is a picture I took when trying to figure out why my wife's start stop is disabled, with no eco light, but mine still functions--and everything I do to disable it causes a light / error message.

Also, noticed this big green cable on mine, but not on her's. I'm guessing it is for HD/ 2 speed transfer, as mine has it, and her' s does not.

Another place to look for an issue is on the positive, main battery. There is a 50A fusible link, and what looks like another isolator. I did not pull it off completely to inspect though.

Hope that helps!

 

[Robuk]

Fugi4, Have you disconnected the battery sensor, if so does the aux now have a charging voltage of around 14 volts.

Members on the Ford F150 forum had problems with the aux battery not getting charged, up until 2018 Ford would code out smart charging, this fixed the issue, they no longer do this. When the battery sensor is disconnected smart charging is disabled and the aux battery should then receive a normal 14 volt charge, it does on my Merc, both batteries are original dated Sep 2011, I checked the starter battery half an hour ago after letting the car stand for over 2 hours, voltage read 12.85 volts, the aux battery read 12.7 volts, not bad for 8 year old battery's. Unless Rover are different to other makes your aux should now get charged once the sensor is disconnected, if not there is probably a fault somewhere.

The sensor on the Merc has now been disconnected for over a year.

 

[Fuji4]

Ok assuming I pulled the correct smart charging sensor it does not appear to have an impact on charging the aux battery. And I do get a charging fault. Let me know if I pulled the right plug.

 

[Robuk]

RANGE ROVER L322 VOGUE BATTERY MAINTENANCE LEAD LR037872.

Works on my 2014 Cayman and the C Class Coupe, no lights on dash and no warnings other than stop/start deactivated. Unfortunately there must be a fault on your car, this sensor disconnect works on many vehicles. Best of luck. Rob.

 

[avslash]

Ok assuming I pulled the correct smart charging sensor it does not appear to have an impact on charging the aux battery. And I do get a charging fault. Let me know if I pulled the right plug. View attachment 10368View attachment 10369 View attachment 10370 View attachment 10371 View attachment 10372

I have tried disconnecting the sensor wire, removing the sensor altogether and running a straight ground strap, and disabling the "smart charging" setting via the GAP tool, and I have never been able to avoid the "charging system fault" message.

I don't think it's your truck in particular, I think it is the way LR has the software coded for these trucks.

I would love to be proven wrong and find a way to get rid of the damned charging nanny without the fault light. Very, very irritating to not be able to bring batteries to full charge.

If we had a EE handy, seems like a solution would be to log the output of the sensor when the system is providing max charge and then build a circuit to plug in between the sensor connector and the sensor to permanently replicate the sensor output that corresponds with max charging.

Of course LR could make everyone's life easy and just turn the crap off as they do on the armored versions of these trucks.

 

[Fuji4]

Seems pretty “dumb” to me. My only recourse at this point is to drop the noco 7200 on it intermittently. I will run the main battery for a while and see if it holds voltage. I do a fair bit of short trips so it might not be getting charged fully and there is a decent load on it with the dash cam, radar detector, etc running

 

[Robuk]

I have tried disconnecting the sensor wire, removing the sensor altogether and running a straight ground strap, and disabling the "smart charging" setting via the GAP tool, and I have never been able to avoid the "charging system fault" message.

Having done that, did the system fully charge both battery`s, if yes then can you live with that misleading fault message to ensure your battery`s continue to get fully charged. Without the sensor my Porsche does not indicate the current charging voltage, to ensure everything is working as it should I plug one of these in the cig lighter from time to time. If the meter reads between 13.8 and 14.2/4 volts everthing is OK and there is no actual charging fault.
If disconnecting the battery sensor was detrimental to the charging system I am confident that two of the most respected manufactures Porsche and Mercedes would make the driver aware of this.

 

[blacktie]

so is the consensus here that, If you don't want to use the start/stop function you have to live with the "ECO" light? I sure would like to get rid of it...