As in http://www.fullfatrr.com/forum/post400047.html#400047 I fitted a new Bosch S5 110AH battery in the bottom of the rear offside compartment in place of the storage polystyrene container which normal houses the removable towbar.

The battery is connected to the 100A input circuit to the rear fuseboard and an earth point I installed for it.

The installation of the battery was straight-forward only involving minor alterations to the space before fitting. this involved removing the two cable ties securing the 20mm dia cable harness to the floor and cutting off the vertical screw studs used for the cable ties to give a flat floor to sit the battery on. Also it was desirable although possibly not absolutely necessary to cut away the securing bracket that normally holds the polystyrene container in place.
I did all the cutting with a cutting disc on a Dremel.

In order that the battery sat flat in the space I cut a piece of 10mm XPS board to size, placed it in the bottom and simply dropped the battery in.
I then used some pieces of XPS board to pack either side and front end of the battery to stop any movement of the battery.

I then created a dedicated earth point for the battery by drilling an 8mm dia hole in the top rail above the fuseboard close to the access hole in it, cleaned some paint off round the hole and fed an 8mm stainless steel bolt through the access hole and through the 8mm dia hole from the rear. Fitted a stainless steel washer and nut and tightened into place.

The cables for the battery are 16mm2 battery cable or welding cable.
After measuring the required cable lengths and adding a bit so they are a generous fit I fitted 16mm2 x 8mm dia copper crimp fittings to one end of each cable. To the other ends I crimped 25mm long pieces of 8mm dia copper tube so that the cables could be securely fitted into the battery terminals.
I then fitted the cables and battery terminal clamps to the battery, fitted the new 16mm2 cable to the fuseboard connection and fitted the battery earth cable to my new dedicated earth point using an 8mm wing nut.
I may change this wing nut connection in the future to a battery isolating switch if I can figure out how to fit one in place in what is a relatively compact space when the front carpeted panel is re-fitted.

A word of caution, if you are not confident connecting the battery +ve connection to the fuseboard when the fuseboard connection is live disconnect the front battery -ve terminal before you start.

It's then a case of re-fitting the black plastic tray over the newly installed battery so the front panel and floor panel can be re-fitted. I found it necessary to "trim" some bits of the underside of the tray to allow the tray to sit correctly.
I found a junior hacksaw and a sharp craft knife easily coped well with this.

Having now fitted two batteries in parallel giving me 220AH capacity it should minimise the need for battery charging periodically particularly if the car is used routinely however if you consider charging necessary the best way to do this is to disconnect one battery and charge the other and vice-versa. Hence the wing nut connection. This would be made even easier if a battery isolating switch was fitted to the front battery. This charging protocol is particularly important if you use a Ctek or similar charger. I would have to contact Ctek and ask them about using their chargers to connect two equal capacity batteries in parallel. For convenience I have a Ctek charger cable connected to a spare fuse position on the rear fuseboard and earth so that the charger can sit in the boot space whilst charging with the 5A power cable going out at the top end of the lower tailgate.

I have added a few photos at the end showing the above for clarification.

Now for the more interesting bit.

If indeed you do fit an battery isolating switch to the front battery -ve terminal, as I have, together with a wing nut connection for the rear battery -ve connection you then have the option when the car is parked up of which or both batteries you chose to operate the car on. Either battery will run the car once it is parked and locked.
One thing about battery isolating switches - if you switch a battery off using one, take the key out. Don't turn it to the off position and leave the key in place it will almost certainly still bridge the contacts if you do.

You therefore have the choice of parking up the car, opening the bonnet and isolating the front battery, closing the bonnet and locking the car. The car will then run on the rear battery for the period it is parked. No doubt it will possibly discharge to the extent you may need to un-lock the car manually.

However in this scenario sitting at the front of your car you have a fully charged battery. All you have to do is open the bonnet re-connect the front battery via the isolating switch and start the car as normal.

ie what you have is a dedicated Starter Battery.

Caution, do not try to start the car with the rear battery only, particularly if the battery is fully charged, the 100A connecting cable to the front of the car is inadequate for this purpose.
If by chance you make a mistake and try to start the car with the rear battery discharged and the front battery not connected you are not likely to cause damage, the current draw will be well below 100A and you car won't start anyway.

There you have it, install a second battery the same size as the one in the front of the car and isolating switches to each battery and you have a dedicated starter battery for those occasions when your car may let you down by not starting after being parked up for a while.

I don't doubt the above could be automated but I personally prefer the idea of simplicity.

Why didn't you fit a split charge relay so when the key is out the battery is isolated from the system anyway?

That's where I'll be putting my fridge battery, probably using one of Traxide Electronics dual battery kits. http://www.aulro.com/afvb/projects-tutoria...ation.html Ron B. VK2OTC
2003 L322 V8 Auto
2007 Yamaha XJR1300
Previous: 1983, 1986 RRC; 1995, 1996 P38A; 1995 Disco1; 1984 V8 County 110; Series IIA

Last edited by p38arover on 11th Aug 2016 11:59am. Edited 1 time in total

In a word "Simplicity".

Nothing to stop a split charge system being used but you would then have to disconnect the "car functions" from the front battery to ensure the batteries are isolated. Essentially you would be using the second battery as a more normal "Leisure" battery to run the car.
I also prefer the idea of having 220AH available for normal day to day use, I could even possibly sit with the radio on for more than 30minutes.
From my point of view having a dedicated starter battery is something to use only occasionally by choice

I fitted a second battery in the same position but used a voltage sensing relay to isolate the 2nd battery whilst the engine is not running. An aux connection on the relay when grounded via a switch overrides the relay if emergency power is required to start the car. Connections are via anderson plugs so I can easily connect my solar panels or remove the battery. On the front main battery I have provided a feed to a plug hidden just inside the grill to connect a charger or solar panels if required. I also disconnected the rear load space 12v cigar lighter type outlet from the car loom and connected it directly to the 2nd battery. The 2nd battery is a drycell so no fumes, spillage or corrosion worries in that enclosed area.
I don't like the idea of the loom running across the bottom of the of the space the 2nd battery sits in so I have lifted it out and it runs nicely in the slot below the fuses 2007 TDV8 VSE
2003 TD6 gone.
2002 P38a gone
1999 P38a gone
1997 p38a gone
1993 VSE gone
1992 VSE gone
1966 Series 2a with V8 conversion gone

@Nicedayforit - did you run the +ve cable from the front battery to the rear fuse box or did you connect the +ve cable to an existing fuse (e.g. suspension compressor fuse) in the rear fuse box.

If you ran the cable from the front, please share the route you laid the cable and also the length of cable you used.

Thanks

In a TD6 there is an existing red 16mm2 cable rated at 100A running from the front of the car to supply the rear fuseboard. It can be seen on the third photo looping into the fuseboard connection on the rhs of the fuseboard. On top of it is my 16mm2 red new battery cable also looping into the same connection.
When the front battery is disconnected by an isolator or whatever, the rear battery back feeds the car via this existing cable.
No need to run a new cable from the rear to the front.

I assume a similar cable supplies the rear fuseboard in later cars also.

I have also fitted a resettable fuse on the second battery for safety and quick isolation. If your second battery is hard wired to the car I would do the same and also have a warning by the main battery to inform a second battery is permanently connected

Click image to enlarge

Nice Day, Do you have a clamp to hold the battery down? I can't see one in the pix.

I've just stripped out that side of the load space and am measuring up to see what size deep cycle I can fit. If I use a hold down clamp, it appears the maximum size battery is 400 L x 180 W x 170 H.

The want/need for a battery clamp is a problem as it really bites into the available height.

wayneg wrote:

The 2nd battery is a drycell so no fumes, spillage or corrosion worries in that enclosed area.
I don't like the idea of the loom running across the bottom of the of the space the 2nd battery sits in so I have lifted it out and it runs nicely in the slot below the fuses

Does fitting the second battery have any affect on the alternator?
Assuming the batteries are both charging sufficiently without overloading it ?

@wayne g

Although the second battery is permanently connected to the rear fuse board and hence the 100A rated cable to the front of the car I don't think any benefit will accrue from fitting a fuse / isolator to it.
That 100A cable is already protected by an existing 100A fixed fusible link although a separate fuse might well be more accessible. As for quick isolation I'm not sure why this would be an issue in my particular installation and use to which I put my car. The purpose of my second battery is to provide an upgrade in battery capacity on the car which imo was under provided for by LR. The fact that by fitting an isolator to the front battery that battery can then on occasions be used as a dedicated starter battery is entirely good fortune.
The wing nut used on the earth connection is a possible quick release device which I accept could be improved by fitting a battery isolating switch. Still thinking about this.
I have fitted a warning label adjacent to the front battery drawing attention to the rear battery fitted.

@p38arover

No I don't have a clamp on the battery, although it might be an improvement such a robust clamp is difficult to achieve without inhibiting battery size and therefore capacity.
The battery is well secured front to rear and side to side by XPS board packing and partially by the black plastic top frame and side panel.
In my situation I consider this to be adequate, I generally don't use the car off-road and usually the car is mostly upright. The battery also weighs in at 26kg so I will rely on gravity to some extent.
For anyone using their car off-road with a rear battery install I would certainly recommend a robust battery restraint clamp.

Quite why leaving the existing cable harness running in it's present position along the bottom of the void with the second battery sitting alongside is a problem I don't quite understand. Can you elaborate?

As regards battery ventilation, why should this be a problem? Half the air that comes into the cabin from the front for the benefit of the occupants exits through the compartment in which the battery is located. This volume of air is surely more than adequate for battery ventilation purposes.

@Baltic Blue

The second battery has no affect on the ability of the alternator to charge adequately. In reality why should it, the electrical load on the car is exactly as it was before the second battery was fitted, all I have done is increased the stored battery capacity.
The alternator used to give out 14.0V to 14.1V continuously before the second battery was installed and still does.

Ron, The battery I fitted was an Oddessy Extreme PC1700 in a steel shell. I do not use a clamp, just cut the intruding bolt from the bottom of the space, lift up the loom and re-route into the slot under the fuses, then wedge the battery with suitable packing pieces. Once the top is back in situe it seems rock solid. I used one of the Narva type voltage sensing relays that I have used on other cars, cheap and effective.
http://www.odysseybattery.com/extreme_batteries.aspx
http://www.ebay.com.au/itm/EXPRESS-POST-NA...Sw6n5XrTLO

I moved the harness as my car is used regularly off road and on extended trips on dirt roads with harsh corrugations, my concerns are that the battery could shift and rub through the wires under these extreme conditions in remote areas, peace of mind for me if nothing else and a 2 minute job. Fusing a 2nd battery is a common safety item here in Oz, generally 2, one each end of the cable. For $10 again its peace of mind, I dont want a fire, seems silly not to. Acid fumes can make a nice meal of your bodywork and are explosive. ask any Merc owner with a battery in the rear wing, even with batteries with vent hoses that are located in a purposely vented area of the car.
http://www.fridge-and-solar.net/dual_bat.htm 2007 TDV8 VSE
2003 TD6 gone.
2002 P38a gone
1999 P38a gone
1997 p38a gone
1993 VSE gone
1992 VSE gone
1966 Series 2a with V8 conversion gone

Last edited by wayneg on 12th Aug 2016 12:16pm. Edited 1 time in total

How does this 2nd battery set up compare to the way the L405 is configured for 2 batteries? (Electrically)

Nice idea, however, as above - a few things to consider / google etc -

Fumes can be a problem - the battery needs to be completely a completely sealed type to be in the passenger compartment - that one isn't - I'm not sure if there is a law/regulation you're breaking, but it is a concern. Lead/Acid batteries leak hydrogen - which is an explosive gas.....

It needs to be secured in place - but putting the floor panel back in might do that - otherwise needs a strap or clamp - again, not sure if it's a legal requirement, but if the worst happens, you don't want that flying around....

The batteries should be disconnected from each other when not charging - otherwise, 2 batteries actually start to flatten each other so you could be in a worse position.....

Theres quite a good write up here -

http://www.fridge-and-solar.net/dual_bat.htm


This thread has got me thinking though - on the L405, both batteries are in the boot compartment, so I guess there is either a ventilation system, or it's a safe place to put them.......