Dual battery setup for 2.8 1GD

[gxl_d4d]

I'm getting 13.5v at idle after driving for a hour. 13.65 on cold start up. There's no hall effect sensor on the negative to measure current. Same set up as 120 series d4d. I have a 2019 2.8L. Been running redarc battery solenoid since new, no dramas with it dropping out or issues charging under bonnet aux battery. I'm running a flood deep cycle.

I don't have a diode in my new car, did in the old one.

[JimmyC]

So just some information for those in the market for an itech 120x lithium battery (330mm model).
Although it physically will fit in the spot behind the driver's headlight it sits within 10mm of the intercooler pipe. At idle there is no interference but when the engine is torqued up the twisting of the motor makes the pipe and battery rub. I have seen others with prados on other forums run them without issue but just something to think about.

[Shane&Sarah]

Hi all…..
I’ve been reading up on the dual battery thread an it’s all back and forth and everyone has their opinions obviously……
could you tell me what would best suit my needs??? I have a 2017 Prado and I’m wanting to run a second battery under bonnet. I have a 160watt solar panel that I’m going to mount on my rooftop tent so system would need to accommodate that.
All I can see myself running is a couple led lights at night and a 40 or 60ltr Engel depending where an how long I go away as I own both! The car would be probably driven every day or every second whilst using this setup
cheers mate, any help I appreciate

[Tony76]

Will earth the DC-DC back to the main battery. The aux battery I will earth to the body, there are 2 earth point already used by factory wiring right where the aux battery goes.

[Gurilla]

Ok cheers mate, also where are you earthing the dcdc Charger? And also where are you earthing the aux battery ?

I havnt earthed mine as I just installed it when I go on trips and have the battery independent currently while I don’t have a dcdc charger

[Tony76]

Haven't decided which fuse as I only checked current fuses and only efi fuses worked on ignition, the rest had current and others where higher amps, got to check a few of the non used fuse slits and see if one of those is suitable when I have more time on the weekend.

[Gurilla]

Are you just using a fuse in the engine bay? If so wich one ?

[Tony76]

I am about to install mine this weekend and bought a piggy back fuse which I intend on using to connect the blue IGN wire to. I really can’t see any harm in using the IGN wire whether it is required or not and connecting it using a piggy back fuse is an extra 5 mins work and $5 so I would rather just do it.

[Gurilla]

It has a ignition trigger on the projector

does anyone on here have one and has used it with out the ignition and any issues ?

[LeighW]

Lowest you'll get is probably around 13.2V but keep in mind voltage drop across the cable to the DCDC so may get down to 13V for instance. If the DCDC can handle that then it should work. Just get one that has an ignition trigger and you can always connect it later if required.

[Gurilla]

I still can’t work out if I need a ign wire source for the dcdc ? After reading this

some people are saying the alt is temp sensor ??and don’t need it ? But does the car give out enough volts for the dcdc to turn on and off ??

i an Looking at a projector dcdc 25a Charger look to be good value



Says it will turn on 13.4v and turn off 12.8

also does this dcdc act as a isolator ? For example it will disconnect from main battery when off ? Or will it keep running off it until 12.8 and then disconnect ? If that makes sense ? All fridge etc will be ran off aux so only the power will run off aux even with car off ? Or will it draw off both batteries until 12.8? Or isolate the start and draw from the aux only

[Gurilla]

I’ve never installed a dual battery before or done much electrical work to cars

but I did it in my 2018 prado hardest part for me was running 6b&s wiring from battery to rear as it’s so thick !

i got a plastic battery tray off eBay $15. Clamps from battery world, wiring,lugs and 70amp circuit breaker from jaycar.. think 70amp is little big for just a fridge ? But the 6b&s is rated to 100+amps

installed a Anderson plug in rear, cut off cig point on fridge and put Anderson too

I havnt installed a vsr or dcdc yet as we just do short trips and I charge the battery out of car but the 105ah last 3 days with the fridge If i pre cool it and the food/drinks few days before

simple install and when I need to install a dcdc everything else already done for me !

[Krich38]

Hello,
I want to install a dual battery. How hard is it for someone without much auto-electric knowledge? My ideal situation would be dual battery under the bonnet, outlet at the back for the fridge. I want to also have a USB (even the current one in the 2018 prado near the gear stick) to be wired to the dual battery for constant power supply. Has anyone had luck doing this? Can someone tell me what parts I need.

[dezzert storm]

Yes my SCI80 can certainly do it too - its convenient to attach a charger/solar panel to either battery and charge them both.

Hi Michael, just wondering how you have found the SC80 a few years on. Seriously considering adding one of these to my recently purchased 2.8. Cheers

[Gurilla]

Thought I’d post here instead of making a new post, I ran a 6 b&s cable to the back of my car for a fridge from the aux battery, I was recommended from jay car to use a 70amp circuit breaker off the positive just after the battery ? Is this to large or is this fine ? The full length of the #6 cable is roughly 5 meters from engine bay to back wheel arch where a 50amp Anderson plug is, I had also cut off the cig plug on the Waeco and put a 50amp Anderson plug too? Is this fine or should I change any thing ?? The cable is also from Jaycar so assuming it’s a decently quality cable too?