Had to wait a long time to do this, until I felt it was about time to replace my existing battery a Varta Silver 110ah/920 crank. Replaced with exactly the same model battery up front, leaving me with the opportunity to fit the old one in below the rear right cubby.

Lovely tidy job that....I get worried in cold months after using the FBH if there will still enough juice for starting so might look at that, but then I'll have to look as to where to put the detachable tow ball....FF ownership sure is "fun"  GONE 2010 Facelifted 3.6 TDV8 - Stornoway Grey + 22" Overfinch Olympus
HAVE 1999 Discovery 2 GS 4.0 V8 - Silver - Off Road Toy
GONE 2013 L405 4.4 SDV8 Vogue. Black with Silver roofline and 22" s
HAVE 2015 Jaguar XF.

Yeah, exactly what was needed from the factory TBH. I think the only mode I would make to that is to add an isolator switch to save having to lift trim if you wanted to disconnect it.

great job Tim [as usual ] , put into wiki. ... - .- -.




Y. O. L. O.
.

I have thought about doing this with my TD6.

Did you have to run any cables from the existing battery location or are the connection points already in the boot area. I which case it is just a case of making up cables to fit that area?

If it's the later, it seems like a job I could do myself.

Great mod by the way, very neat and tidy

@ iphs

see the photos, my earth lead was long enough to run around the spare wheel compartment to attach to the earth point behind the LR seat, and the live connection goes onto the right of the rear fuse box.

@ mzplcg

Yes, an isolator in plain view would be handy. Had hoped that the quick release fittings might be more accessible....

@stan

thanks  .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

OK Joe,

So the fitting seems reasonably easy, thank you, I will probably get on with this at the weekend. I might go with the idea of an isolator switch as well.

Couple of questions:

Will the car draw power from both batteries without having to fit relays or changeover switches?

Will the alternator charge both without without the same relays/changeover switches and will the standard alternator be man enough for the job?

With reference to the sticker: What would be the consequence of trying to start the car with the front battery disconnected?

Cheers

@iphs ( You may wish to search this and other FFRR forums regarding 2nd batteries to get more qualified answers to your questions)

Will the car draw power from both batteries without having to fit relays or changeover switches?

Yes, so I understand, but you can fit relays and changeover switches to control charging/usage.

Will the alternator charge both without without the same relays/changeover switches and will the standard alternator be man enough for the job?

Yes, so I understand - time will tell ( I am expecting my alternator to be the next thing to break, anyway!

With reference to the sticker: What would be the consequence of trying to start the car with the front battery disconnected?

The cables on the second battery and the wiring back from the rear end is not really capable of coping with cranking amperages, hence the fuse to prevent melting cables and/or fire!! Might work in an emergency, though..... .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

Thanks Joe, I will do some research.

Hi Joe,
With regard to separating the batteries: if batteries are not isolated from one another they should be the same type (which you have) and the same condition (which you don't have). Otherwise (as the 2nd battery continues to age) you can end up in a situation where the battery in worse condition continually draws current from the better battery and actually lessens your potential avail. CCA vs. using only one battery (and increase the likelihood for "HDC Inactive" bongs)...

Not something that you need to be worried about, but something to be aware of. What is a bit silly, tho, is that if you wait until probs manifest themselves you'll once again have a not-brand-new battery to work with. So if you then replace the older battery with a newer unit you'll be in the same situation as now...

I have a dual battery system as well - but it is for running my fridge when we go camping. I used something similar to one of these http://www.ebay.co.uk/itm/M-POWER-SPLIT-CH...258ccaa6d5
Course, as you are interested in increasing your everyday battery capacity not in running accy's, this is not of much use for you...  
RRC 2Dr, RRC 4Dr,
P38, and 2 L322s
(wife thinks I'm nuts - prob right, too)

Last edited by SteveMFr on 24th Jun 2014 12:44pm. Edited 1 time in total

So Steve, would it be possible for forum members to add a second battery and have (like a Transit van) one battery purely for starting and battery two for everything else?

Theoretically that would not be too hard to do. In practice I see a couple of problems - #1 being that with all the electronics, you'll need to have everything powered at once when starting. If you then imagine a flat starter battery and a healthy secondary battery, you are going to be running much more current through the wiring from the rear battery than it can handle, and
This is the good thing about Joe's set up: if one battery dies it kills the other with it so no great potential differences in charge.


I'm sure there is a way to do it safely, but I'd have to look at the wiring diags. Serious question or more academic? 
RRC 2Dr, RRC 4Dr,
P38, and 2 L322s
(wife thinks I'm nuts - prob right, too)

Thanks for additional advice/input SteveMfr.

I purchased the new battery based upon my Ctek refusing to charge it through the ancillary socket (white) on the towbar, telling me it wouldn't take a charge. However when I connected direct to the battery it took a charge fine. This was after having the car off the road for nearly two weeks without starting up, but unlocking and locking, doors opened etc.

So I am hoping B2 is in fairly good nick, but I am tempted to go for an isolator as you mention, which looks like a good product.  .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

I am not sure which way to go with this Mod at the moment.

In an ideal world the second battery would (when the engine is not running) supply power to the interior lights and other systems that draw power every time the doors are unlocked. This seems to be the main source of battery problems for me (why does the interior have to light up like an oil rig every time I unlock the doors?).. This would leave the starting battery reasonable unscathed if the car isn't started for a number of days. Then of course the second battery would be re-charged whilst the engine was running.

If that is to much to ask for, I may do the Mod as Joe90 but add the split charge system as SteveMFr suggested.

That way I would have a battery for use with aux equipment if required and/or a spare fully charged battery for starting in an emergency. I do take onboard the warnings about trying to start the engine from this second battery and I would use an isolation switch to disconnect from the car and use jump leads to the jump start points in the engine bay.

I am sure if there is a problem with this one of you fine gentlemen will enlighten me.

To get the best of both worlds it seems a modulator for general use with a bypass switch when you need both batteries to work together ?

@iphs you will need some long starter cables!  .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999