Software Patch for 2nd Battery System?

[RoverLander]

I've just replaced a MY2010 Discovery with a MY2015. I had a DC/DC charger and second battery in the old car. My TPMS display shows voltage and it never dropped under 13.1v while driving the car.

I noted during dealer servicing that they seem to have registered the car as having a second battery system. It is printed on each service invoice.

The new car drops as low as 12.2 volts while driving and the battery has been fully charged. I am about to install a DC/DC charger and second battery in the new car.

I am wondering if Land Rover dealers take note of second battery systems and then install a software patch to ensure the car stays above 13.1 volts at all times. Does anyone know?

p.s. This post is not about DC/DC chargers Vs other charging systems for 2nd batteries so i wont be getting into that discussion.

Peter

[discotwinturbo]

I have an MY12 and my dc to dc charging works perfectly fine. Has never switched off from low voltage.

I am guessing that my redarc bcdc20 is not effected at all by what is happening upfront as the battery is just fine and fridge and accessories never run out of power with my needs.

Battery is in the rear with power taken from the 30amp white plug in the back panel where the tow hitch was located.

Maybe the MY12 has a higher voltage like your previous MY10 ? I actually thought it worked from as low as 9 volts so would 12.1 be an issue ?

I would guess it's only a visual observation that you have a second battery.

Brett...

[Redback]

I've just replaced a MY2010 Discovery with a MY2015. I had a DC/DC charger and second battery in the old car. My TPMS display shows voltage and it never dropped under 13.1v while driving the car.

I noted during dealer servicing that they seem to have registered the car as having a second battery system. It is printed on each service invoice.

The new car drops as low as 12.2 volts while driving and the battery has been fully charged. I am about to install a DC/DC charger and second battery in the new car.

I am wondering if Land Rover dealers take note of second battery systems and then install a software patch to ensure the car stays above 13.1 volts at all times. Does anyone know?

p.s. This post is not about DC/DC chargers Vs other charging systems for 2nd batteries so i wont be getting into that discussion.

Peter

Why would it be affected, the DC to DC charger only relies on power from the main battery to work on charging the second battery, the cars software wouldn't know it was there, as it's only connected to the battery and works seperatly from the cars software

I use a DC to DC charger in the trailer to charge the battery in the camper, it's powered by the car, never had the car serviced at a dealer, never had an issue, I can't see any dealer doing what you say, I think it's more likely a record of what's in the car, so if there is an electrical issue with the car, they can blame your second battery setup and refuse any warranty claim.

Baz.

[RoverLander]

The standard redacr DC/DC charger will cut out at 12.7v or below. That is why they created the LV (low voltage) versions which use an active ignition on wire to turn the charger on.

You are right in that the car doesnt know that the DC/DC charger is there. I am just wondering why my old car would stay above 13.1 volts while the new one regularly drops below 12.7 volts. I though that maybe the dealers are trying to avoid possible low main battery voltage caused by directly connected second battery systems. The software could be changed to keep voltage above 13.1 volts. Its just a theory.

I will ask the dealer on my next visit. I will also have a look if anything changes once i connect the DC/DC charger.

[drelectro]

I've noticed the same behaviour with my MY15 too, it regularly drops to 12.2 volts or so whilst the engine is running (no 2nd battery system fitted).

Seems odd to me too.

I'm measuring from the accessory socket in the vehicle so it may be that the actual battery voltage is higher though.

[jon3950]

The battery management system in MY13 and later models significantly changes the way the alternator charges compared to earlier models. It basically only charges when there is spare power available, such as on overrun. There are a few threads on here already about this and Drivesafe has provided some excellent information.

This causes quite significant fluctuations in the charging voltage you will measure, depending on what the engine is doing and is nothing to worry about.

There is no magic software that LR apply to vehicles with second batteries. Think about it from a purely commercial perspective, why would they put effort into solving a problem that isn't theirs?

My dealer, and I assume therefore LRA, know about my second battery and have no problem with it. They have already replaced a battery under warranty without question. Of course if the Traxide unit caused damage to the vehicles electrical system (which it won't) they would not cover it under warranty and nor should they.

Cheers,
Jon

[drivesafe]

Hi drelectro, and you are right, using the accessories socket in any vehicle can give you lower voltage readings of up to 1.0 volts or more.

The voltage drop is caused by other high current devices drawing power from the same MAIN power supply circuit, that is providing power for the accessories sockets.

The only way to get accurate alternator voltage readings is to take the readings at the cranking battery's terminals.

Hi RoverLander, it does not matter what load you apply to the D4's electrical system, the state of charge of the cranking battery is the only thing that effects the operating voltage in these vehicles.

But note, they are having problems with continual low operating voltages in some of the new D4s.