3rd Battery Mounting Locations

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ForealBoreal

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I am wanting to install a third battery into my 77 for the purpose of running 12v accessories without compromising my 24v starting system. I have an arb fridge freezer coming and I do not want to have to worry about camping with it running and not being able to start my truck in the middle of no where. I have bought a Redarc BCDC1220 to isolate and charge the 12v battery.

I have seen pirahana battery trays but I am not going to pay anywhere close to what they want for one of those and to mention the shipping it would run me to get them here.

Does anyone have any info on how they mounted a 3rd battery in their 70 series. I would preferably like to do this all under the hood.
 
I think the best way would be to mount them sideways,the opposite to how they are now. The 1HZ has lots of room down the LH side of the RHD models.
If you dont want to buy one ,then you will have to make one.
Maybe get a piece of square tube or flat bar and run it down the side of the engine bay picking up as many of the captive nuts as possible.
Then weld 3-4 45 and 90 degree hangers from there to pick up the bottom of the tray.

On the single tray I installed ,I also fixed some bolts with rubber stoppers on the end to the underside of the tray and let them sit on the inner fender for some extra support.
 
Not sure about RHD trucks, but on my CDM BJ70, I extended the left side battery tray near the front of the truck. I moved the starting solenoid forward and use the capture nut to mount the battery tray bracket I built. If you get the right size batteries you can turn them 90* and put 2 in side by side. The front battery butts up against the upper rad hose, but it does not push on it too much.

Now I run all the 12 V stuff off the 3rd battery and change it from the 24 V with this.

I'll take some pictures soon.
 
aamiggia said:
Not sure about RHD trucks, but on my CDM BJ70, I extended the left side battery tray near the front of the truck. I moved the starting solenoid forward and use the capture nut to mount the battery tray bracket I built. If you get the right size batteries you can turn them 90* and put 2 in side by side. The front battery butts up against the upper rad hose, but it does not push on it too much.

Now I run all the 12 V stuff off the 3rd battery and change it from the 24 V with this.

I'll take some pictures soon.
Click to expand...

Please do!
 
I have 2 batteries on the left hand side of my rhd lj70, which fully take up the space. I can't see any place to mount a 3rd battery.
 
which would be more efficient in a 24v system


a second small 12v alt putting out about 45 amps into the third battery

or

a larger 24 volt 60 amp alternator and one of those converters


it would have to be the converter id say? a second alt is a constant drain on engine power, whereas the charger can be selectable.
but how much more resistance is there from a 60 amp alternator, compared to the 30amp in there now..
theyre a nice find, i had a look maybe a year ago and such a converter wasnt available, the most they went up to was 10 0r 12 amps.
 
OK. Here is a picture with some comments.
P4218458_paint.webp
 
I'm using a yellow top upside down in front of the gas tank under the passenger seat on the driver's side (RIGHT!) on my 77. That's right, under the truck. Using a marine battery tray, all stainless and plastic.

Ample room, no danger of hitting the axle or road debris. It sits up higher than the frame bottom, so it's protected too.
 
Found this on a HZJ73 on the forum. I have seen similar done on a troopy but I cannot dig up the picture.

attachment.webp

I took the plunge and bought piranha trays from Australia a while back. I will be installing them in November.
attachment.webp
 
I mounted mine in the cab in my drawer unit, charged with the 30A version of the charger aamiggia has.

It would have been nice to get them all under the hood, but it seemed like an awful lot of weight to be all hanging off one side like that. I'll be interested to see how it works for you.

The redarc looks quite interesting.
 
bj70_guy said:
It would have been nice to get them all under the hood, but it seemed like an awful lot of weight to be all hanging off one side like that.
Click to expand...

i have to counter balance mine due to that, when she's empty - like now during my tourer build - she leans to the left with a big 100ahr cranker under the hood (all that will fit) and a 240ahr agm behind the LHD seat, doesn't help being LHD and were talkin about 70kg of battery. previous to recently dismantling, i used to have to put nearly all the heavy gear on the RH side so she's sit straight, that's with practically brand new tjm HD 2" lift kit. whilst i will use the power, half the reason finally decided to fit a seemingly excessive second 240ahr behind the RH seat was to even her up!

if i had another rig where i couldn't put batteries behind the front seats for whatever reason, I'd also go for one under the floor as someone else said/did, provided you build a decent tray and guard i can't see any problem, even with deep river crossings. batteries don't really like engine heat anyway and there's more important stuff to squeeze in there i reckon.
 
The ARB fridge runs better on 24V.

I have been out in both the HJ61 and HZJ77 for 10 up to days at a time with the fridge running all the time the key was in the "on" position, whether parked or driving - battery draw was never a problem.

Was out last year for 2 weeks in the fall with an F350 Diesel and it was on the whole time making ice - battery draw was not a problem with the fridge. We were driving the truck for up to two hours per day during this time, and not less than 45 minutes.

Try to run as many 24V accessories as possible, and you can avoid the need for a 12V battery altogether and keep the system as simple as possible. If you have two healthy batteries, I feel very strongly that additional batteries and the added weight are not needed... along with the added cost.

I feel strongly that keeping weight down and keeping all systems as simple system as possible on an expedition or long-trip vehicle is important for overall reliability.

~John
 
John what kind of batteries are you running?
What mode do you set the fridge to for battery management?

I had issues with my set up running High battery savings and my fridge losing temperature over time while camping and staying parked.
 
ForealBoreal said:
John what kind of batteries are you running?
What mode do you set the fridge to for battery management?

I had issues with my set up running High battery savings and my fridge losing temperature over time while camping and staying parked.
Click to expand...

I think I have it on low or moderate battery savings, but I'll check the next time I power it up - which will be in a couple days as I'm off to Beaverlodge and Dawson Creek again. You have to make really sure that the vents on each side of the fridge are very free to breath cool air or the efficiency drops right off to nothing.

In the HJ61 I have Napa (Deka) Group 27s and in the HZJ77 I have AC Delco Group 27s.

~John
 
Piranha battery trays are in.
A little bit of work to get them in.
A bracket was completely off that needed to be modified slightly with the use of a zip disc and welder.
One bracket on the little tray was either wrong or completely off making it useless.
Otherwise happy with the install.
More wiring fun to come to make it a more painless wiring system in my eyes.
image-3450992883.webp
 
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