Thread: Perentie batteries

12 or 24

Slide the battery boxes out, take a pic and post the pic here and or

Take a pic under the bonnet of the alternators and post up.

In case anyone is still looking for info I post the following about what I have done.

Good quality 86s seem thin on the ground or incredibly expensive so I looked into which battery to fit and which will fit in those rear compartments.

For the RFSV I have purchased and installed CAT 175-4390 (calcium) batteries which are each 90ah . If you take the time to decipher CAT battery sizing IMHO you can end up with greater cranking amps and a better warranty. While these batteries are a few mm taller than 86s they still fit on the slide with adequate top clearance - but they may not fit the underseat battery box (I have been meaning to check that but I haven't got one due to the 2nd fuel tank being fitted). The batteries have threaded terminals but CAT can supply adapters to fit the type used for Perentie battery terminals.

Each battery is rated at 1000 cca which was appealing to me as it should always have a good reserve if not used for some time.

CAT batteries seem to have, IMHO, a superior warranty (5 yr pro-rata). Mine have been in the RFSV for 3 years to date and don't get charged very often but keep the SoC well.

175-4390: 12V 31 BCI Battery | Cat(R) Parts Store

Originally Posted by Blknight.aus

The radio battery side of you ffr is 24v.

You have (or should have if its not been molested) what is known as a series parallel configuration which means you have 2 pairs of batteries in series with each other that are then joined in parallel.

If thats the case you cant just hook up to one of them. You have to hook up a 24v charging source to a pair of them on one side of the vehicle (or a viable.input on the power box) and then both pairs off batteries will charge at the same time and rate.

DO NOTsimply.hook a 12v charger to one battery amd expect it to charge all of the batteries if your FFR batteries are in the stamdard wiring condition. When the 24v alternator kicks in you will kill that battery if you do it repeatedly..

Please go about this carefully. Get a multimeter (a cheapie $10 supercheap special is all you need) and get some.help. battery and wiring fires are a good way to wreck your perentie.

Thanks for clarifying the configuration. Yes it’s in standard configuration just as you describe it (I assume). It’s hooked up the 24v generator belt-driven from the motor. Zapping a few KW I expect. I’ll run the multi meter around and see what it says.

I guess a main question is what the plugs that say ‘EXT GEN IN’ and ‘EXT BATT IN’ actually do...? Do you think one of these (or both) is indeed a viable input?


The battery condition might be poor so I might be in the market for new batteries after all- thanks for the tip on the CAT batteries 87County I’ll have a look at those. If I have to replace the batteries I’ll perhaps reduce the auxiliary system to a pair, rather than 4, due to my need for the power being fairly limited.

The oem 24v interpolating alternator is capable shovel out over 100 amps but should be configured in the 40amp mode.

As there is no regulation inside the distribution box any terminal you can get voltage out of you can put it back in on..

Obviously the best one to use is the aux gen in socket.

If you want to use a single maintenance charger foe the whole vehicle get a small24v to 12v dc/dc charger and wire it up to the outlet of the distribution box amd the banana plugs in the dash.

You can also go back the other way using the 12v via a 12/24v dc dc charger to trickle up the radio batteries.

If you are desperate once the engine is running the 13v on the 12v side is enough to excite the 24v side so the alternator will take over.

Set about 1200 rpm and very quickly bery briefly bridge the 12v +ve to the 24v +ve .

To go the otherway you can center pole the 24v system to the 12v side to get starting voltage for a push start. You can also start the vehicle that way but it will shorten the life of the battery you are not jumping from.

No do not try to use the bridge wire as negative for anything on the vehicle in an effort to equalise the batteries. Bad things happen.

Originally Posted by Blknight.aus

If you want to use a single maintenance charger foe the whole vehicle get a small24v to 12v dc/dc charger and wire it up to the outlet of the distribution box amd the banana plugs in the dash.

You can also go back the other way using the 12v via a 12/24v dc dc charger to trickle up the radio batteries.

thanks again for your replies

my objective is to be able to run a fridge off the auxiliary batteries and to be able to top up those auxiliary batteries with a solar panel - i've attached here a picture of the solar panel regulator - would it work ok to plug this directly into the EXT. GEN. IN 24V socket? Or does the regulator need to be designed for a 24V system?


the banana plugs?! I noticed them - Blknight would you please clarify where they are wired to? Could you draw from them to charge something and/or plug back into them to trickle charge and if so this would only trickle charge the cranking battery?


here are a few pictures that describe the battery set-up:

IMG_0931.jpg
IMG_0919.jpg
IMG_0922.jpg
IMG_0923.jpg
IMG_0925.jpg
IMG_0926.jpg

I also wonder what the 23V read-out from the power box indicates - some poor battery health? Not sure what a 24V system should show - but i assume 24V!

With the vehicle not running, a couple of the auxiliary batteries are reading over 12.7V and a couple reading just 10.4V approx. - but i have not taken the wires off the terminals and tested the batteries while they are not connected to each other

an album of higher res pics here Land Rover Perentie FFR Auxiliary Battery System - Google Photos

merry xmas all

Originally Posted by 51mondays

thanks again for your replies

my objective is to be able to run a fridge off the auxiliary batteries and to be able to top up those auxiliary batteries with a solar panel - i've attached here a picture of the solar panel regulator - would it work ok to plug this directly into the EXT. GEN. IN 24V socket? Or does the regulator need to be designed for a 24V system?


the banana plugs?! I noticed them - Blknight would you please clarify where they are wired to? Could you draw from them to charge something and/or plug back into them to trickle charge and if so this would only trickle charge the cranking battery?


here are a few pictures that describe the battery set-up:

IMG_0931.jpg
IMG_0919.jpg
IMG_0922.jpg
IMG_0923.jpg
IMG_0925.jpg
IMG_0926.jpg

I also wonder what the 23V read-out from the power box indicates - some poor battery health? Not sure what a 24V system should show - but i assume 24V!

With the vehicle not running, a couple of the auxiliary batteries are reading over 12.7V and a couple reading just 10.4V approx. - but i have not taken the wires off the terminals and tested the batteries while they are not connected to each other

an album of higher res pics here Land Rover Perentie FFR Auxiliary Battery System - Google Photos

merry xmas all

Ok stop..

I can see the pics and you habe some issues. Easu to solve but i need tomget onto.a computer and not the phone to qrite up.a good.poat.

Of.your batteries you habe 2 that are ok so you can salvage the system quixkly.in the short term and swap.batteries in pairs.

Next you nees to.establish if your frisge can run on 24 v8

ok firstly you are in the standard 2x12 in series with another 2x12 in parallel giving you 24V.

you need to grab me the readings for all of the batteries but if the voltages are the same left to right you have 2 good batteries (the 12V ones) and 2 flat or dying batteries the 10v ones. They may all yet be salvageable.

the 23V in the plug indicates that the system is wired up normally and minus cable losses is what I would expect to find with a ~12 and ~10V combo of batteries.

the best thing you can do at this point is thoroughly clean all the batteries, check and correctly top up the fluids, take them out wire them up in parallel charge them over night as a 12x4 parallel bank then put about a 100w load on them for 20 minutes to an hour, disconnect them all for 10 minutes and then check the voltages again. That will tell us which batteries are salvageable. I will refer to this later as "bank testing"

but first lets see if your FFR setup still works properly.

with your meter in the same socket start and run the engine to about 1200 rpm use the hand throttle to set it there. check to see if you have around 28v showing on the meter, if you don't check to see if the volt gauge in the distribution box is showing any voltage. if its not cycle the main red circuit breaker switch a couple of times.

if you get ~28V stop there your system works and we now just need to deal with your batteries.

if it doesn't shut everything down and check the cannon plug on the back of the alternator if its not fitted properly refit it and repeat the test. if that works. its all good to go.
if it doesn't then theres a couple of more invasive things that need to be check out.

From here on in I will be talking about your battery and system voltages in nominal voltages.

the regulator you have is not suited for charging your 24v system, you need to get 24v worth of panel and a 24v regulator. Firstly you need to establish if you can take advantage of your 24V system. If your accessories are not 24v then its generally best to pull down most of the 24v system and rewire it to a full 12v parallel system and install something like a traxide db80. I happen to know a guy who, if you need to go that way, has just bought himself a 6x6 and will probably shout you the DB80 and rewire work if you're willing to supply the wire to do your mods and leave the no longer required FFR parts behind. The skys the limit for what can be done for you in this guise including halving the system and putting in a small 12v100a Honda alternator charger in place of one set of batteries, adding an inverter you name it it can be done just drop me a PM to discuss. Shameless plugging done... back to your issues

Bare in mind that some fridges are actually more efficient on a 240v supply to the extent that running an inverter to run the fridge is actually more economical than running the fridge straight off the batteries.

The quickest cheapest, dirty but effective fix for you is as follows.

Wire up your solar panel to the 12v system and install a 12-24V dc/dc switch mode battery charger, (various methods of protection for the 12v side may be required depending on how "dumb" your selected charger is) typically a 7A unit will be sufficient. wire it up to a cannon plug and snake that through to the aux gen side of the distribution box.

this will only be something in the order of 70% efficient compared to running a straight out 24V solar charging system but has some other advantages. the biggest one being that you can disconnect the main alternator and still get a maintenance charge on the batteries every time you run the engine or charge the starter battery.

when you disconnect your batteries....
turn off the isolator switch in the FFR box (red one)

start with the earth on the drivers side pair (in your pictures this is the black wire with the yellow heat shrink and the blue insulated connector of the red/black pair adjacent to the battery labelled 4762 in red) when its disconnected insulate it
goto the other side
Disconnect the joining and distribution box negative lead from the passanger side batteries (this is the double black wires in the photo labled img_0922) insulate it.
now disconnect the +ve then insulate it
remove the bridging strap
remove the battery frame top
lift out the 2 batteries
remove the +ve lead from the drivers side battery (labled 4762 in red in your photos) and insulate it
remove the bridging strap
remove the battery frame top
lift out the 2 batteries.

to install simply do the sequence backwards installing and connecting where your removed and disconnected.

when you install batteries carry out a bank charge and bank test of them. If there is more than about .3v difference between the batteries after they have been left to sit they will not give you the best possible life when paired and used as intended in the FFR's nominal configuration. The best option is to have the batteries closest in voltage in the series pairs for example. 4 batteries test out with these voltages

12.2 11.8 12.3 11.7 you would get the highest overall voltage if you paired the 12.2 with the 11.8 to get 24v and the 11.7 with the 12.3 for the same 24v and then put them in parallel. BUT the batteries with the highest voltages would do the lions share of the work while discharging and when charging once they had reached their nominal charged state would still be required to pass the charging current to the lesser charged lower voltage batteries and would boil off their electrolyte.

if you paired them as 12.2 and 12.3 for 24.5v and the 11.7 with the 11.8 for 23.5v you would see about 23.7 but as the batteries are closer to matched they will provide a longer discharge and do it for more cycles.

And that will do for now...

you're more than welcome to track me down on my phone which if your say it backwards and quickly sounds like

mine for sex mine for ate ate oh for oh.

Originally Posted by Blknight.aus

Ok stop..

I can see the pics and you habe some issues. Easu to solve but i need tomget onto.a computer and not the phone to qrite up.a good.poat.

Of.your batteries you habe 2 that are ok so you can salvage the system quixkly.in the short term and swap.batteries in pairs.

Next you nees to.establish if your frisge can run on 24 v8

many thanks!

the fridge is an Engel MT45 that'll run on 24V - i will replace one of the 3-pin Yeonhab female plugs with a posifit, or make an Anderson/Yeonhab adaptor and leave the box original

i've disconnected the batteries from their wiring to check the voltage each is at:

drivers side
12.3 & 11.5

passenger side (where the charge is delivered?)
12.6 & 10.3

IMG_0948.jpg
IMG_0949.jpg

Land Rover Perentie FFR Auxiliary Battery System - Google Photos

note: the car has been sitting for one week without being driven - the cranking battery is at 12.8V

I've no idea how old any of the batteries are, they came with the vehicle, from the auction, and i've had it about 18 months