My SDV 8 has a large 2nd Battery Standard

[Bails]

I had not looked until today but was pleasantly surprised to find a large 2nd Battery.

My thoughts are I will upgrade this to the biggest battery that I can fit Lipo 4 will be my aim. My research to date indicated a very small battery or none at all. Seems the Australian versions of the SDV8 come with the large battery.

[SBD4]

I had not looked until today but was pleasantly surprised to find a large 2nd Battery.

My thoughts are I will upgrade this to the biggest battery that I can fit Lipo 4 will be my aim. My research to date indicated a very small battery or none at all. Seems the Australian versions of the SDV8 come with the large battery.

What are you hoping to do with it? Disconnecting that will disable the "Stop/Start" function which would be a plus.

[Bails]

What are you hoping to do with it? Disconnecting that will disable the "Stop/Start" function which would be a plus.

Size is 10 X 6.5 X 8 inches L X W X H , which means I should be able to find a decent LIPO 4 battery to put in there to run my accessories. I would be interested to know why such a large battery , from my research there seems to either a very small battery or just a capacitor.

I am well pleased to see this setup, I am hoping it will just be a swap out no need for a DC to DC charger. Yes it would be good to get rid of the stop start function but that isn't so much an issue as I turn off all the time.

[SBD4]

Size is 10 X 6.5 X 8 inches L X W X H , which means I should be able to find a decent LIPO 4 battery to put in there to run my accessories. I would be interested to know why such a large battery , from my research there seems to either a very small battery or just a capacitor.

I am well pleased to see this setup, I am hoping it will just be a swap out no need for a DC to DC charger.

That's what I have seen also. Mid you I have never bothered to check what is installed in mine. What year is yours?


Yes it would be good to get rid of the stop start function but that isn't so much an issue as I turn off all the time.


Yep, 1st button that gets pressed after the car is started is the stop/start button.

[Bails]

​

iTECH054 12v 54Ah Lithium Ion Battery - LiFePO4 Deep Cycle Camping RV Solar Slim Line | iTechworld (https://itechworld.com.au/collections/lithium-batteries/products/itech054-12v-54ah-lithium-ion-battery-lifepo4-deep-cycle-recycle-camping-rv-solar-slim-line)

[Graeme]

What are you hoping to do with it? Disconnecting that will disable the "Stop/Start" function which would be a plus.I understand that heated seats will stop working too.

[Bails]

My wants are different, I am after a second battery that will run my fridge and Cel Fi and not switch the outlets off when the ignition is off.

It looks like I will have plenty of space to put up to 100 amp hour Lipo 4 battery in. I now have to check if the standard electrical system will charge the Lipo4 OK, which I am thinking it will.

If this all works it will be a very simple upgrade ,

I will be towing a van so I may also want the ability to have the second battery connected to the van which will have it's own solar and batter source.

[Gregz]

from the 2014 WSM:
The dual battery system used on TDV8 4.4L Diesel in all markets and TDV6 3.0L diesel in cold climate markets with
or without stop/start system, differs from the dual battery system used on vehicles with the all markets stop/start
system. The dual battery system uses the auxiliary battery which is switched in parallel with the primary battery if
the ambient temperature falls below a certain threshold, or the state of charge of the primary battery falls below a
certain level. The function of the auxiliary battery is to assist the primary battery in cranking the car at a suitable
speed to provide a start.
In addition the dual battery system in TDV8 4.4L Diesel isolates all electrical components and systems sensitive to
low supply voltage from the primary battery while an engine start is in progress and supplies them from the auxiliary
battery.

[Bails]

from the 2014 WSM:
The dual battery system used on TDV8 4.4L Diesel in all markets and TDV6 3.0L diesel in cold climate markets with
or without stop/start system, differs from the dual battery system used on vehicles with the all markets stop/start
system. The dual battery system uses the auxiliary battery which is switched in parallel with the primary battery if
the ambient temperature falls below a certain threshold, or the state of charge of the primary battery falls below a
certain level. The function of the auxiliary battery is to assist the primary battery in cranking the car at a suitable
speed to provide a start.
In addition the dual battery system in TDV8 4.4L Diesel isolates all electrical components and systems sensitive to
low supply voltage from the primary battery while an engine start is in progress and supplies them from the auxiliary
battery.

It seems the only time both batteries are in parallel is in cold conditions. This may be a problem as itech say their batteries should not be connected to batteries with different chemical structure. I aim to keep investigating but with my limited knowledge it seems I may be able to set up as desired.

[drivesafe]

Hi Bails, you can not connect lithium and lead acid batteries together because the lithium battery will have a constant settled voltage of around 13.2v over most of its discharge cycle.

Whereas a lead acid battery reduces voltage from around 12.7v for a fully charged battery down to around 12.1v for a lead acid battery at about 70% discharged in a STOP/START and a variable voltage operating system. Which is how your vehicle works.

The lithium battery will hold the voltage high and your BMS will not see a need to run your alternator at a high enough voltage to charge your batteries.

So you could suddenly find you have two flat batteries, when the lithium is finally discharged enough to cause a voltage drop in the lithium battery.

You need to use a DC/DC device to charge the lithium battery.

[Bails]

Hi Bails, you can not connect lithium and lead acid batteries together because the lithium battery will have a constant settled voltage of around 13.2v over most of its discharge cycle.

Whereas a lead acid battery reduces voltage from around 12.7v for a fully charged battery down to around 12.1v for a lead acid battery at about 70% discharged in a STOP/START and a variable voltage operating system. Which is how your vehicle works.

The lithium battery will hold the voltage high and your BMS will not see a need to run your alternator at a high enough voltage to charge your batteries.

So you could suddenly find you have two flat batteries, when the lithium is finally discharged enough to cause a voltage drop in the lithium battery.

You need to use a DC/DC device to charge the lithium battery.

OK this makes sense, seems to me that the 2nd battery is only in the circuit when the engine isn't running . I am no auto electrician , but to my simple mind this would be the design. Also of note is some cars have a very small battery and some have the larger, so unless a different electrical system is used , which it may , hooking a small secondary battery into the starting circuit would make no sense.

So if I need a DC to DC charger, which seems likely , the problem will be isolating the OME input , charge, circuit I would assume.

I know you can now but Lithium starter batteries, which since I want to tow a Van may be a good weight saving measure , I am wondering how if these batteries are fitted they are charged?

Really appreciate the input , it has taken me ages to get around to this , it might be I just have to fit a 3rd battery on the LHS with a DC to DC charger and just run my accessories from this.

[Bails]

Build a DIY Lithium LiFePo4 Headway 12v Battery replacement - YouTube (https://www.youtube.com/watch?v=5IPnQieycyA)

DCS LiFePo4 Lithium Under Bonnet Setup with Alternator Charging - 12 Month Review - YouTube (https://www.youtube.com/watch?v=FbStDC-7Q9E)

My thoughts are why not put two batteries in, replace the standard battery and if space allows put the other where the current 2nd battery is?

I think space will work out by laying the second battery on it's side. My current batteries are 5.5 years old so replacement will be coming up , Nig plus is I'll be 20 kg less in weight.

[Gregz]

Hi Bails, you can not connect lithium and lead acid batteries together because the lithium battery will have a constant settled voltage of around 13.2v over most of its discharge cycle.

Not sure if it makes a difference, but the RRS batteries are specified as AGM.

[drivesafe]

Build a DIY Lithium LiFePo4 Headway 12v Battery replacement - YouTube (https://www.youtube.com/watch?v=5IPnQieycyA)

DCS LiFePo4 Lithium Under Bonnet Setup with Alternator Charging - 12 Month Review - YouTube (https://www.youtube.com/watch?v=FbStDC-7Q9E)


Hi again Bails, that second video is about lithium batteries installed in a Toyota.

Toyotas have a simple Variable Voltage alternator operation, and this is totally different to you Land Rover SMART alternator operation.

While that company shows a D4 set up with a lithium cranking battery, there are no reports on how it actually performs with the LR SMART alternator.

I suspect the D4 BMS will continually see what it thinks is a fully charged cranking battery and will not start to charge the lithium battery until the lithium battery is near flat.

As stated, just my suspicion as there is no feed back on this type of setup in any modern Land Rover.

[Bails]

Hi again Bails, that second video is about lithium batteries installed in a Toyota.

Toyotas have a simple Variable Voltage alternator operation, and this is totally different to you Land Rover SMART alternator operation.

While that company shows a D4 set up with a lithium cranking battery, there are no reports on how it actually performs with the LR SMART alternator.

I suspect the D4 BMS will continually see what it thinks is a fully charged cranking battery and will not start to charge the lithium battery until the lithium battery is near flat.

As stated, just my suspicion as there is no feed back on this type of setup in any modern Land Rover.

OK so If I put Lipo4 batteries in both positions, so now have like for like, do you see an issue?

DCS are claiming that their batteries are drop in and have built in BMS ? My thoughts are since my batteries are old replace both and I can have 200 amp hrs of lithium on board.

[drivesafe]

Hi again Bails, contrary to the claims that company makes, you have a vehicle with a SMART alternator, as such, the voltage varies between 12.2v and 14.7v, depending on the state of charge of your batteries.

Because lithium batteries run at a constant 13.2v, until they are nearly flat, your D4's BMS will see the battery voltage is high and will not try to charge the lithiums.

In a worst case scenario you are likely to drive from one camping spot to another, leaving one location with low lithium batteries and arriving at the next location with flat batteries, regardless of how long you drive.

The advertising is all good and well, but short of replacing your alternator with a special one, and then fitting the lithiums, just dropping lithiums into your existing setup is likely to be a Russian Roulette type of operation.

As stated above, no one has posted up how vehicles with SMART alternators ( like yours ) work with lithium batteries.

[drivesafe]

Hi again Bails, can I make a suggestion, that should help you determine whether you will actually be able to fit a lithium battery and be able to charge it properly.

Just a suggestion, but before you do anything about battery upgrading, buy two BM2 Bluetooth Battery Monitors and fit one to each battery and driver as you normally would for about a month.

Then post up what you find and you should then know if it is a viable proposition to go to Lithium batteries.

[Bails]

Hi again Bails, can I make a suggestion, that should help you determine whether you will actually be able to fit a lithium battery and be able to charge it properly.

Just a suggestion, but before you do anything about battery upgrading, buy two BM2 Bluetooth Battery Monitors and fit one to each battery and driver as you normally would for about a month.

Then post up what you find and you should then know if it is a viable proposition to go to Lithium batteries.

Thanks I really appreciate the help. I think I have a wiring diagram , and if the 2nd battery isn't in the circuit when the car is running this is what I may do.

Put in a Dc to DC as you have suggested. Put in device to stop discharge at 80%, what ever these are called .

If this makes sense and can happen I think it will be my best option, battery to run fridge and accessories but enough left to power car accessories when engine is off.

[drivesafe]

Hi Bails and as I posted, I think you need to learn what your vehicles charging system does, before you spend any money on something that may cause problems.

A DC/DC will mean the batteries are separated, this may not be the correct way to go as your alternator can recharge your batteries at close to 100 amps per battery and the best you can achieve is 50 amps for one battery.

You could just try taking the earth/negative ( - ) lead off your second battery and see what occurs.

[Bails]

Hi Bails and as I posted, I think you need to learn what your vehicles charging system does, before you spend any money on something that may cause problems.

A DC/DC will mean the batteries are separated, this may not be the correct way to go as your alternator can recharge your batteries at close to 100 amps per battery and the best you can achieve is 50 amps for one battery.

You could just try taking the earth/negative ( - ) lead off your second battery and see what occurs.

Now have the full workshop manual on the electrical system. Just need to "decode". do now understand how it works not sure I will be able to do the mods I wanted though. If you want a copy of the link let me know.

[pwe]

My wants are different, I am after a second battery that will run my fridge and Cel Fi and not switch the outlets off when the ignition is off.

It looks like I will have plenty of space to put up to 100 amp hour Lipo 4 battery in. I now have to check if the standard electrical system will charge the Lipo4 OK, which I am thinking it will.

If this all works it will be a very simple upgrade ,

I will be towing a van so I may also want the ability to have the second battery connected to the van which will have it's own solar and batter source.

I am in process of installing a second battery, Lithium slim line 100Ah battery inside the LHS in boot area with a DC/DC redarc charger plus a couple relays, which all fit nicely tucked away behind the side panel. I installed 2 Anderson outlets on the other side of the boot area in the little alcove. I have a RRS 2016 not sure yours is the same setup, but have a look..
cheers, Peewee

[SBD4]

I am in process of installing a second battery, Lithium slim line 100Ah battery inside the LHS in boot area with a DC/DC redarc charger plus a couple relays, which all fit nicely tucked away behind the side panel. I installed 2 Anderson outlets on the other side of the boot area in the little alcove. I have a RRS 2016 not sure yours is the same setup, but have a look..
cheers, Peewee
Welcome to the forum mate!

[drivesafe]

Now have the full workshop manual on the electrical system. Just need to "decode". do now understand how it works not sure I will be able to do the mods I wanted though. If you want a copy of the link let me know.
Hi Bails and yes, I would very much appreciate the link.

Thank You.

[Bails]

I am in process of installing a second battery, Lithium slim line 100Ah battery inside the LHS in boot area with a DC/DC redarc charger plus a couple relays, which all fit nicely tucked away behind the side panel. I installed 2 Anderson outlets on the other side of the boot area in the little alcove. I have a RRS 2016 not sure yours is the same setup, but have a look..
cheers, Peewee

Have the same model year. Yes I am now of the opinion that the best bet is to do what you have done. You said have a look ? Where would I find this? I am thinking of putting the Lithium on the LHS , adding DC/DC and perhaps an inverter so I can charge my e-bike batteries on the go. Have you designed a battery mount ?

I have now obtained manual , so have a better idea of the system.

[Bails]

Range Rover Sport Dual Battery System Tray | AutoElecOz (https://autoelecoz.com.au/product/range-rover-sport-dual-battery-system-tray/)

[Gregz]

seems like a lot of $ for a glorified bracket.

[Gregz]

Hi Bails, are you progressing with this ? I need to do something similar... also keen for suggestions of getting power cable from new battery out the back to an anderson plug without compromising water-tightness.

[Bails]

Hi Bails, are you progressing with this ? I need to do something similar... also keen for suggestions of getting power cable from new battery out the back to an anderson plug without compromising water-tightness.

I have two Anderson Plugs , I didn't install my Son in Law did but looks neat , unsure how they exit. I am up to installing Light Bar and Cel Fi Go , Thinking for now is just run the Cel Fi from second battery as only half Amp draw.

I may leave the Lipo 4 battery install for now , need to do more research and am having difficulty getting info. I would really like to replace second battery with Lipo4 but can't get a definitive answer on my questions.

At the moment I am looking into weights for towing , I reckon I have about 500 kgs available on the rear axel , vehicle has 750 payload but rear axel weight is an issue.

I have noted the 7 seat has 200 kg higher rear axel weight but can't find out what components have been changed to allow this?

[Pedro_The_Swift]

take off ball weight,, and??
I should be ok,, not planning on anything in the car behind the front seats except two puppies...
and I hope for only 200 on the ball

[Bails]

iTechworld are now claiming drop-in IPO4 batteries for all vehicles including those with smart alternators. I have sent them electrical system manual and asked if this would mean the second battery would still charge as I will have to replace both batteries.

If I can replace the batteries with LIPO4 I will save a lot of weight and also now have the ability to run fridge and of course charge the second battery via solar.

Let's see what turns up.