Hi guys I ve been getting the low battery waring on my car of late and I know im doing some short trips but reckon the little battery in the back is probably old so thought I'd give it a go seeing as its winter too!

I have had a look around and there are many posts about with questions on this and afert doing some research on the best prices and what is required thought I's make this up to save others some time and maybe cover it all off in one place!

Im not mechanic so use my ramblings as you wish!

Swapping out the aux battery on L494 Range Rover Sport also see replacing the main battery on the L494 Range Rover Sport here https://www.rrsport.co.uk/forum/post607599.html#607599

The L494 and L405 for the most part have a secondary battery (leisure battery) that boost the main battery to keep some of the systems alive either when the engine is not running but also to assist with starting the engine if the ASS system is active (Automatic Start stop) this was a feature on most of the diesel engines and on some of the later petrol engines AFAIK.
These cars run things like soft close doors, electric tailgates, electric side steps etc… that all take some power and the main battery needs a little help sometimes.
The Aux battery is a 12V 14AH battery and isn’t really that big it about 150mm*145mm*90mm and the terminals are round, its located in the rear right hand side panel in the boot (or trunk for our American pals) (this would be the driver’s side in the UK and passenger for ROW)
The replacement battery is the following OEM unless you have cash burning a hole in your pocket and want to go to a stealer!

EXIDE EK151 AGM AUXILIARY CAR BATTERY (this batt is 15AH so its one better!)
Cheapest I found at the time of this 07/12/20 was £38.50 plus £4.99 Shipping from the Battery Group https://batterygroup.co.uk/
This is an easy home user swap over (only a little bit of faff!)
Tools you will need.
Charger (just to make sure the new battery is fully charged (it should be already though)
Claw hammer or pry tool (this is to ease the side panel off)
Socket or spanners (socket is better)
8mm for the battery bracket
10mm for the terminal clamps
Light
Cup of tea and maybe a biscuit or 2, or even better maybe a can of beer after all you will earn it for doing man stuff!
Step 1
Unlock the car and open the tailgate, don’t bother putting ignition on and ideally let the car shutdown by leaving it for a bit when the interior light goes off it will be asleep (perfect time to drink that tea whilst get all the stuff ready!)
Step 2
Use the claw hammer of pry tool and ease the panel in the rear off, just a gentle pull and it will come away, it’s held in place by 3 push clips



Step 3
Remove the vent hose which just pulls out
Step 4
Get the 10mm socket and slacken off the bolts for the terminals (when you remove the terminals you can use the covers that come from the new battery terminals to protect the terminals of the old battery during removal) the red positive has a plastic cover that just unclips
Remove the NEGATIVE Terminal first, that’s the Black one!
Then remove the Positive and move out of the way. The cables are attached to the bracket.



Step 5
Grab the 8mm Socket and undo the bolt on the bracket, it is only on the side you can see (the other side is slotted into the body work), its quite a long bolt.
Then place the bolt in a safe place and then gently lift the bracket up and slide it about left and right, this is the faff bit!
If you lift the bracket upwards and pull it a little in towards the centre of the car and jiggle the battery about there is just enough room to slide the battery out from behind (as in move the bracket as if it were a minute hand and turn it to about 1900, at the same time lift it upwards, and it should give just enough room to slide the battery out towards the rear of the car. (this is the reason to put those plastic terminal covers on to avoid the terminals touching)
Persevere it’s not that hard it is possible with some jiggling, the bracket slides into a slot and if you wiggle it from side to side it will loosen up a bit and the battery will move about a little.)



The battery should now be out. Maybe a quick swig of tea if it’s still warm or now you can crack open the beer as you are halfway through the hard part.



Step 6
Take the plastic terminal covers off the old battery and put them on the new battery ready to slide it back into place
Make sure when you put the new battery in it faces up the right way with the terminals at the top
Step 7
Now that you have put the battery in its place don’t tighten the bracket up yet so it gives you a bit wiggle room.
Take of the terminal cover for the positive side and then put the cable back on and tighten securely
Then take off the terminal cover on the negative side and put the cable back on and tighten securely
You can now put the bracket clamp bolt back in and tighten it up, its handy to have some card or think plastic strips to slide in between the bracket and battery just in case its not a perfect fit and moves slightly as this will help pack it down and stop any sliding.
Step 8
Put the rear panel back in place (I didn’t remove mine totally I kind slid is open like a door so the end by the seat was still in place. But I think it should be the bottom section in first) push it home and give it a little tap with the bottom of you fist to secure the clips.
Step 9
Clear things away and keep the old battery somewhere safe until you are happy to get rid of it (I don’t think these are covered under warranty if your car is still covered but its worth trying it I guess first, but certainly would want to pay for a diagnostic)



Good work it’s done and you just saved yourself a ton of cash from having a dealer do it! Now you can get back to being annoyed by start stop for a bit anyway!
Here is some additional info I’ve gathered up about this and tested some of it myself!
1. Resetting the BMS (battery management system) I didn’t need to do this, I have a GAP IID tool which does have this function on it and one t reset the main battery too, there are rumours around saying this needs to be done, I'm still not sold on if this needs to be done or not, I don’t think it does, I had a low batt warning prior to swapping out m battery (of late I have been doing some short runs so that doesn’t help either plus its cold and the seats and steering wheel heating have been used along with AC and lights!) After replacing the battery I didn’t get the low battery warning so the car must know there was a plenty of charge. Not exactly sure how the BMS would know the battery had been changed rather than charged as its not a smart battery, my guess this has come about from the manual in the cars stating batteries should be replaced by a dealer (mainly for financial gain!
When I tested mine the ASS icon came back on the dash and when starting the icon flashed green and then goes out, and when I pressed the button I got a message saying it’s not available but I believe was caused by several scenarios see below.

2. The system won’t work if the following conditions are not met
External Temp is less than approx 0 degrees C
External Temp is more than approx 40 degrees C
The engine has not reached temperature
The driver’s seatbelt is not fastened
Demand from the AC requires the engine to be running i.e. defrost
Battery is low (lots of short trips can result in the battery never getting a chance to reach a good charge)
Bonnet/hood is open.

3. The BMS reset recommendation is probably a good idea if due the battery having issues and being low that faults have occurred which the system will store and so if the battery gets replaced even though there is now more charge the system might not re-activate said systems until a reset has been performed as a safe guard. That said it doesn’t say this in the manual it just instructs you on how to remove the battery and say Consult a retailer or authorised repairer!

To perform a battery reset should you wish too you have several options!
1. This is the best option, if you don’t already have one by a GAP IID tool, (this is a Bluetooth OBD2 diagnostic tool but also allow for vehicle configuration and fault finding, not to be confused with cheap fault readers! The guys at GAP are truly good, its is well worth the investment. BAS (Bell Auto Services) remaps sell them and (also if you have a new enough car can remap your car using this tool remotely so no need to go to a garage and the map could be removed prior to dealer service I guess) others do the sell them too!
This tool has a service function that allows you to reset the main battery and or the second battery, its simple and I believe all it does it clear any battery related faults from onboard modules and maybe clears out some charging info the alternators uses to regulate voltage.
It that simple and you have the added bonus of having the GAP tool to check for faults and to changes some stings on the car if you are brave enough (if you have the hardware on your car then things can be enabled that were not spec’d at the time of purchase so you might find a few hidden treats)

2. Go to a local indy and ask them if they can perform the reset for a few quid or maybe ask them to do the replacement and reset which will cost more
3. Do the swap yourself and see if there are any peops on the forums nearby that have a GAP Tool that isn’t locked to a VIN (the tools are locked to a VIN unless you use them for work then you can pay extra to get another VIN added)
4. If you are luck and the car is in warranty just go to a dealer and complain and you might get lucky!
5. Go to the dealer and ask them to diagnose and replace as required and then reset, I'm sure this option will leave you in tears and put the other half in a right old mood for the next week!

Hope this helps someone! If a jobs worth doing, get a someone who knows what they are doing to do it!

RRS Autobiography Indus
RR P38 HSE V8
RRS Supercharged Santorini
AMG CLK Rear Tyre Shredder

Last edited by pjbracer1 on Thu Dec 17 2020 2:26pm. Edited 2 times in total

Just a reminder, the L494's from about 2017 on have a capacitor in that position which replaces the secondary battery, so if you look there and their is no battery then you have one with the capacitor.
Regards
Barry 2017 Range Rover Sport TDV6 L494 SE Fuji White
2011 Range Rover Sport SDV6 L320 SE Fuji White Loved but GONE
2010 TRAKKA Motorhome Fiat Ducato GONE (What a dud, don't buy one)
2006 Discovery 3 SE TDV6 Automatic Chawton White/Ebony. Loved but GONE
2006 BMW X5 diesel White/Charcoal, Bought new, Gone after 12 years! Was Excellent.
Ex Member Range Rover Club NSW

I guess that means those later models on dont suffer from the same issue? As that would be a great after market mod if it could be done instead of a batt repalce! If a jobs worth doing, get a someone who knows what they are doing to do it!

RRS Autobiography Indus
RR P38 HSE V8
RRS Supercharged Santorini
AMG CLK Rear Tyre Shredder

I read your guide with interest. If only the writers of technical manuals could write in the same basic English as you do. Particularly the writers of IT related instructions. Its a particular bugbear of mine that in even basic guides, jargon is used constantly and items are described by acronym rather than spelling it out at least the first time the acronym is used. Even basic things like my central heating timer settings are a nightmare. Most of us are not car mechanics but with some common sense and plain English instructions including photos, then many similar tasks like the one you described can be accomplished.

Well done! RRS HSE Dynamic SDV6 2014

Nemo mortalium omnibus horus sapit

Cheers mate Im in IT and know exactly what you mean, Id like to think I can turn my hand to most things technical but sometimes its just isnt easy when the person writing the instructions is generally too close to project and leaves out steps, Ive even worked with Microsoft to get some of their own instructions changed when they missed out some vital steps!

Worst thing is rembering to take pics, the PowerfulUK guys are pretty good at making vids on how to do things and are pretty detailed. If a jobs worth doing, get a someone who knows what they are doing to do it!

RRS Autobiography Indus
RR P38 HSE V8
RRS Supercharged Santorini
AMG CLK Rear Tyre Shredder

My start/stop in my 2016 HSE hasnt worked once since I bought the car about 5 months ago, do you think this is what I need to do to get it working again? And yes I'm sure its turned on

My start/stop in my 2016 HSE hasnt worked once since I bought the car about 5 months ago, do you think this is what I need to do to get it working again? And yes I'm sure its turned on

So a quick updte on this! After chagning the aux battery and doing as i have i stopped getting the low batt warning but start stop only worked after i had fully charged the main battery!

So as the were both the originals i decided to replace the main too and the start stop has started functioning again!

I got the main battery for 126 delivered from the battery group and will write up a swap over guide as i took loads of pictures.

So i think the start stop is using the main battery in the boot and the aux battery help run the systems in the car to help the main battery

I opted to change the aux as it was cheaper as it was only 38 quid but whlst the warnings went away ASS didnt work (i now realise how annoying it used to be though!

So if you go to the battery group and buy both of them you might as well do the sap at the same time as its all in the boot area!

The price for both is still less than one of them from Eurocarparts or Halfords and definietley cheaper than a dealer.

Not is still have not performed a battery reset or re-programming using the gap too on the mian batteyr and everything works as it should with no issues

main batt chage did stp the boot working but ony cos power was cut i just closed it manually and then it all worked as it should.

Id do both at the same time for peice of mind, my batts were original 2014's If a jobs worth doing, get a someone who knows what they are doing to do it!

RRS Autobiography Indus
RR P38 HSE V8
RRS Supercharged Santorini
AMG CLK Rear Tyre Shredder

How hard was it to change battery and which battery did you buy my stop and start now works since changing the small battery but may aswell change main battery as my vehicle is 5 years old and its got a lot of electrics relying on it lol

have you got ant pictures i take its under that donut looking thing in the boot

Just writing it up now mate and ill post the instructions, its not that hard take out spare wheel, losen the air compressor 2 bolts and it swings out of the way. then lift out some sound baffling foam stuff and you can see the battery in a tub, losen of the temrinals 10mm socket lift out and then put the new one in, I have a few tips that I found whilsts I was doing it so ill stick em in the write up. If a jobs worth doing, get a someone who knows what they are doing to do it!

RRS Autobiography Indus
RR P38 HSE V8
RRS Supercharged Santorini
AMG CLK Rear Tyre Shredder

Hi Mate whats the function called on the iid tool to reset the battery do you know

Go into the service menu and its the battery reset function




the main battery one looks to reset the infor the main ecus have about the battery state and any errors I didnt reset mine yet I jsut swapped over and havne had any issues so I think its only need the reset perhaps if the car is in an error state where some of the functions have been shut down like auto braking and cruise control. If a jobs worth doing, get a someone who knows what they are doing to do it!

RRS Autobiography Indus
RR P38 HSE V8
RRS Supercharged Santorini
AMG CLK Rear Tyre Shredder

Cheers mate havnt got that far yet with my iid tool

ill have alook tomorrow

L494 Main Battery Replacement
I started getting some power related issues such as low battery warnings, auto Stop start not working, lecy tailgate occasionally wouldn’t close on its own, soft close doors would suck the door shut! So after digging around I though it might be the secondary aux battery or leisure battery that helps runs other electronics around the car when the engine is running and to help the main battery during starting so it doesn’t interrupt some of the ECUs in the background!
Anyway I replace that little one the other weekend which is in this post but also a separate one, but after doing so the low battery warnings stopped but the ASS (auto start stop) still didn’t work! So I gave the main battery a full charge over night and then went for a run the next day, and yey ASS worked! So I continued about for a bit and after a few days of some short trips (engine did get to temp but just not long trips), ASS stopped working so I decided that whilst it is an annoying feature when its working I d rather have it working and turn it of than not!
So back on the internet to source the new battery so I went back to The Battery Group and bought the following model which is an OEM replacement its slightly better with 5 more amps but otherwise identical.
It’s the L494 Main Battery Exide EK950 (019 or 017 are the battery specs) It’s a 95AH with an 850A CCA (cranking capacity, which means it’s got plenty of starting power)
It’s and AGM style Start Stop battery which is basically Absorbent Glass Matt so the acid is in the fibre glass matting and are sandwiched between the electrodes so there is no liquid as such. These are supposed to be good for start stop function and can be mounted at any angle too.
https://batterygroup.co.uk/batteries-by-ap...ek900?c=35
(I’m not on commission for these guys either (should be though!)
FYI the L494 Aux Battery is Exide EK151 from the same place if you are gonna do one might as well do the other and make a day of it! Id do the baby one first! (Post 2016 Cars don’t have the Aux batt they have a dirt big capacitor instead! So best check first).
https://batterygroup.co.uk/batteries-by-ap...ar-battery
So now you have the new battery handed to you from the delivery guy who will have moaned a bit cos it weighed 26KGS compared to all the other Amazon parcels he normally delivers! (PS the above company use UPS who a pretty good and give you a time slot for delivery)
All you need for this job is a few tools but nothing you won’t have (if you haven’t then why are you even considering this job!)
TOOLS
Rubber gloves (to keep your hands clean but also for static purposes you will see what I mean later)
10mm socket, ratchet to go with that socket! and a small extension bar if you have one (not really needed but makes it a bit easier)
Plastic tray (like an old take way top or lunchbox lid (you won’t need it for long) something small really as you are just going to put it under the negative lead to stop it accidentally slipping back on the body or terminal!
Pry Tool Plastic only (or Wood) Something to help pry off the terminal and to pop out a cable tie retainer.
Cup of Tea or Beer (I like the start with Tea then end on a beer combo!) Maybe a few cups of tea and if you are really lucky some chocolate biscuits! Then move onto the beer and admire your handy work!

Process
So to start off with unlock the car and open the drivers door (you can shut it back up again that’s fine, then move round to the boot/trunk for the chaps over the pond).
Make sure the car is in Access Mode (I always use this to park with as it make it easier to get in and out but I believe the car considers itself to be parked and is recommended by LR) I'm short so for me it’s a given but also it does help reduce wear on the seat bolsters if you don’t have to slide down the car to get out, Also side steps make it easier too especially when in a tight space)
Empty all the crap out so you have a clear workspace, meanwhile the car will be slowly going to sleep in the back ground (you will notice the interior lights will be on whilst you are getting prepped when they go out the car will be asleep.



Lift up the floor and you will be greeted with some acoustic carpet and a spacer thingy in the middle



Grab the spacer and then un screw it as it has a long thread into the wheel well that hold the spare wheel in place (not sure what the car without this look like but my guess it its still there just without the wheel part! (underneath the wheel is the suspension compressor)



Now get ready for the strain as you will need to lift out the spare wheel (if you have one) that isn’t light (still save a trip to the gym today).
Lift out the foam surround the wheel sits on.



You can now see the suspension compressor which does not need to be disconnected just mover out of the way, if you look at the picture the 2 red markers are the securing bolts and the blue square is where the brack slots into the battery box housing (so it after removing the 2 bolts it slides to the left and then just lifts out (not completely) so you can move it out of the way over towards the seats.
Now you will need to get your 10mm socket and loosen the 2 bolts at 6 oclock and 9 oclock



Being careful of the connections (there is plenty of slack) slide the Compressor to the left to move the bracket section at 3 oclock its held in by like a flat t bar that slots into the palstic housing its nice and simple (Ive marked the sections in blue and you can see in the below image the compressor still connected but lifted out of the way




There is a foam piece that sits on the top of the battery so lift that out and you can now see the battery



There is a red tab over the positive terminal that can be lifted out of the way (its attached to the terminal lead by 2 arms just pinch them together and it lifts).
On the top right disconnect the vent tube
Now here is where the plastic tray come in handy and the gloves!
Loosen the bolt on the negative terminal use prying tool to help lift it off as its quiet snug (USE SOMETHING PLASTIC OR WOOD) then take the plastic tray and place it over the negative terminal so should the negative lead slide back it wont touch the terminal. (Consider the negative lead as if it was the car, so you are disconnecting the car from the battery first)



Then loosen the positive terminal, this is where the glove will come in, its help down by a little cable tie which I couldn’t loosen without lifting the terminal lead so I place the rubber glove over the end of the lead so it didn’t keep touching the battery use a plastic pry tool to lever out the cable tie which is secured by a plug type thing into a hole (it will just pop out)



The battery is now ready to lift out (its not secured it just sits there) )oh there is a piece of foam on the right hand side I guess to stop it moving)
The carpet kinda makes it a bit awkward (could use some duct tape to hold it out of the way I guess)



I used the terminal covers on the new battery to put on the old whilst lifting it out just in case I knocked a lead or something.
So put the terminal covers back on the new battery and lift it back in, there is plenty of room to the right hand side of the battery so I lifted it in on the back edge first and slid it left side first in, it’s a bit tricky but nothing bad.



Then slide the battery to the left as that is where is sits and the connect it all back up in reverse
Take the gloves of one at a time to avoid any accidents
Put the vent hose on first
Positive Terminal first
Then negative terminal (When the negative (the car) is connected the lights and locks might flicker and the car will wake up as if you have just unlocked and opened the door. Just let it do its thing while you put everything back.
The only thing that might not work straight away will be the electric tailgate as power was disconnected from it whilst it was open, just manually close it and then use the unlock function on the keyfob and then it will open again as normal.
That’s pretty much it after you put it all back together (I kept the old battery charged in the garage just in case as its handy as a jumper as it’s not totally dead)

If you have the GAP IID tool then you can perform a battery reset if you are still getting errors or had errors prior to the swap (I have not done this and have no issues)
To do that go fire up the tool and go to the service menu where you will see 2 options one for main battery and one for aux battery. Just follow the on screen guides (I don’t know if it will but you might lose some stored settings but I think this is unlikely as most of it is stored in memory.



Next time you go for a drive and the engine is up to temp the ASS should now function. Only time will tell if the short trips will create the same problem resulting in needing the occasional overnight charge!

Hope this might help someone! If a jobs worth doing, get a someone who knows what they are doing to do it!

RRS Autobiography Indus
RR P38 HSE V8
RRS Supercharged Santorini
AMG CLK Rear Tyre Shredder

Good write up. I changed my batteries a while back & this is what I did to prevent re-setting any thing or using a Gap tool.
If you have a full size spare, its heavy & if your on your own will have to use that useless tool to lift it.

This is what I did as I did not want to be resetting anything. I connected a set of jump leads to under bonnet charging points & connected them to the new battery on the ground. Disconnected old battery & removed it. Connected another set of jump leads to the first set & connected to the old battery. Removed the jump leads connected to the new battery & fitted it to the car. Disconnected the jump leads from under bonnet points. Finished, power always to the car, no resetting.
Sounds more difficult than it is