Dual Battery Build Thread
- Thread starter WanderlostOverland
- Start date
cali.runner
New member
Can you tell me more about the panel acting as a battery tie down?
Is it ABS plastic? Purchased or made?
Will that go on driver or passenger battery?
THanks!
I was out there today with the hood up and was thinking I wouldn't mind a a extra battery, and thought pass side near the firewall is the perfect place to ass a battery. I have an idea to run a fridge and my ham radio off of it. I have a 19 trd pro with the pull out whatever in the rear. That will be it for the electronics for now until I add a few lights on the front bumper. I will be watching this thread. My problem is I will be doing this by myself and that makes me uncomfortable. I might even see if there is a local shop to do it.
WanderlostOverland
New member
Sure, it's a piece of 1/2" thick ABS plastic we found on Amazon. We simply cut it to fit the top of our battery and drilled a couple holes for the battery hold-down.
cali.runner
New member
Is the ABS acting as the tie down bar or will you have it floating on top on a spacer?
Thanks!
WanderlostOverland
New member
It's the hold-down too. Ours is an AGM battery, no vents on top.
awesome looking forward to the video!! You guys have great stuff on 4runner stuff!!
where are you guys putting the fridge? I'm debating on getting the 65 dual zone and putting it behind the driver seat since I remove that section of the rear seat. Currently my RTIC 45 sit there and has more room to fit a bigger cooler...possibly a 65 so hoping the domestic 65dz fridge fit there.
where are you guys putting the fridge? I'm debating on getting the 65 dual zone and putting it behind the driver seat since I remove that section of the rear seat. Currently my RTIC 45 sit there and has more room to fit a bigger cooler...possibly a 65 so hoping the domestic 65dz fridge fit there.
WanderlostOverland
New member
Thanks!
We'll be anchoring it in the rear/passenger side. We need to keep our rear seat, for now.
Looking forward to this one. I've used your vids for installing my Suspension, my front bumper, and the SSO high clearance mod....as well as enjoying your adventures and of course your relationship with your family.
I was looking into a second battery, but decided on a portable second battery pack. I upgraded my main battery, and then built a box in a Pelican Case with a 100Ah Lithium battery...pricey initially, but only 29 lbs and the equivalent of 2 100Ah lead acid batteries.... I used a Redarc BCDC 1225. Its a fantastic product and allows me to charge the Lithium from my car when I drive, Solar, and AC. I highly recommend their products. I use this to run my ARB fridge, and to power all electronics while camping.
I may still do a secondary battery, as my Pelican box is quite large, so I cant wait to see your end results
I was looking into a second battery, but decided on a portable second battery pack. I upgraded my main battery, and then built a box in a Pelican Case with a 100Ah Lithium battery...pricey initially, but only 29 lbs and the equivalent of 2 100Ah lead acid batteries.... I used a Redarc BCDC 1225. Its a fantastic product and allows me to charge the Lithium from my car when I drive, Solar, and AC. I highly recommend their products. I use this to run my ARB fridge, and to power all electronics while camping.
I may still do a secondary battery, as my Pelican box is quite large, so I cant wait to see your end results
What is your battery setup? How long does it hold a charge with a fridge? How often do you need to charge? I wondered if anyone did something like this but havent looked into it much.
Not hijacking. Definitely looking forward to this full write up as it is very similar to what I want to do. Always easier to see what works or doesnt work and have a parts list! Thanks!
WanderlostOverland
New member
If you're squeamish about doing it yourself, Overland Power Solutions specializes in custom installs. They're located in Knoxville TN. Give them a shout!
WanderlostOverland
New member
It's finally done and so far we're extremely happy with the whole setup!
This was a difficult project to do. Not the install and custom fab work, but the research and choosing of the components. The method of charging and battery type to be precise. It seemed that as soon as I made a choice I'd read in a post somewhere that there's something better, or the one I picked had flaws. It turns out there's a lot of misinformation and biased opinions out here on the interwebs. Crazy I know! That's why when it came to finally pulling the trigger we enlisted the help of professionals. They steered us towards trail proven, high quality components that will likely outlast our 4Runner.
The system we put together is not inexpensive. In fact, it cost more then what a lot of folks are willing to spend on a quality 3" lift. Some dollars can be shaved off by going with big fuses instead of the breakers, a simpler fuse hub for the outlet panel, and omitting the monitoring gauge.
We chose the AGM deepcell battery we did primarily for cost. We saw no sense in paying $400 when a $200 battery will do the same job and have the same life expectancy.
We chose the DC-DC charger over the relay/solenoid method for the health and efficiency of our battery. It turns out the AGM batteries are very finicky when it comes to charging and discharging them.
And, come to find out, alternators in our 5th Gens suck at charging one battery, let alone two.
Here's the link to the install video. We hope you enjoy watching it:
YouTube
This was a difficult project to do. Not the install and custom fab work, but the research and choosing of the components. The method of charging and battery type to be precise. It seemed that as soon as I made a choice I'd read in a post somewhere that there's something better, or the one I picked had flaws. It turns out there's a lot of misinformation and biased opinions out here on the interwebs. Crazy I know! That's why when it came to finally pulling the trigger we enlisted the help of professionals. They steered us towards trail proven, high quality components that will likely outlast our 4Runner.
The system we put together is not inexpensive. In fact, it cost more then what a lot of folks are willing to spend on a quality 3" lift. Some dollars can be shaved off by going with big fuses instead of the breakers, a simpler fuse hub for the outlet panel, and omitting the monitoring gauge.
We chose the AGM deepcell battery we did primarily for cost. We saw no sense in paying $400 when a $200 battery will do the same job and have the same life expectancy.
We chose the DC-DC charger over the relay/solenoid method for the health and efficiency of our battery. It turns out the AGM batteries are very finicky when it comes to charging and discharging them.
And, come to find out, alternators in our 5th Gens suck at charging one battery, let alone two.
Here's the link to the install video. We hope you enjoy watching it:
YouTube
Bumbo
New member
Looks good, and a very clean install.
The choice for a DC-DC for your project is ideal… especially for maintaining an AGM in a system where a traditional starter battery is used.
I have built these system professionally before and the crossover point for a ACR is generally when you need a large amount of alternator current being supplied to the AUX side to run large loads… like in a service/fleet van or emergency vehicle... which is not the case here.
It’s probably fine, and perhaps it’s just my OCD, but I always opt for a flipped terminal orientation, where the negative post it towards the fender. I figure in a bad accident where the truck is hit from that side, you help reduce your potential for an engine fire. Driver side starter battery is oriented the same, with the negative towards the fender.
Nice choice on the Victron BMV… expensive, but nice accessory. The Bluetooth option is excellent. That said, monitoring a state of charge using just the voltage on a AGM is generally sufficient. It’s a lot more useful if building a lithium setup using LiFePO4 as the discharge curve is VERY flat and almost impossible to gauge the state of charge based on voltage alone. Either way, no harm in having such a nice monitoring device.
Victron also makes inverters and solar charge controllers that also use the smart bluetooth stuff... makes for a nice system, but I know the DC-DC has a built in charge controller.
I didn't recall you mentioning anything about a LVD (low voltage disconnect). Are you using one in your system?
BlueSea makes an excellent unit sized perfectly for your loads... its programmable via the switch and would be prefect in protecting the battery from over discharge. This is what I run and its been an excellent protection device.
m-LVD Low Voltage Disconnect - Blue Sea Systems
The choice for a DC-DC for your project is ideal… especially for maintaining an AGM in a system where a traditional starter battery is used.
I have built these system professionally before and the crossover point for a ACR is generally when you need a large amount of alternator current being supplied to the AUX side to run large loads… like in a service/fleet van or emergency vehicle... which is not the case here.
It’s probably fine, and perhaps it’s just my OCD, but I always opt for a flipped terminal orientation, where the negative post it towards the fender. I figure in a bad accident where the truck is hit from that side, you help reduce your potential for an engine fire. Driver side starter battery is oriented the same, with the negative towards the fender.
Nice choice on the Victron BMV… expensive, but nice accessory. The Bluetooth option is excellent. That said, monitoring a state of charge using just the voltage on a AGM is generally sufficient. It’s a lot more useful if building a lithium setup using LiFePO4 as the discharge curve is VERY flat and almost impossible to gauge the state of charge based on voltage alone. Either way, no harm in having such a nice monitoring device.
Victron also makes inverters and solar charge controllers that also use the smart bluetooth stuff... makes for a nice system, but I know the DC-DC has a built in charge controller.
I didn't recall you mentioning anything about a LVD (low voltage disconnect). Are you using one in your system?
BlueSea makes an excellent unit sized perfectly for your loads... its programmable via the switch and would be prefect in protecting the battery from over discharge. This is what I run and its been an excellent protection device.
m-LVD Low Voltage Disconnect - Blue Sea Systems
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WanderlostOverland
New member
Thanks for the heads up. I'll look into it.
Bumbo
New member
He is good... All the loads should be powered off the accessory fuse box which is fed by the aux battery only… unless wired incorrectly, there is no chance for the starter to participate in the accessory loads.
The DC-DC is acting as a 1-way charge device which also isolates the two sides.
The only thing he doesn’t have is a LVD, which would prevent over discharge and damage to the aux battery if left discharging unattended. I can tell you one thing, that ive killed more batteries without this, than the device cost. LVD is an absolute must if you want to let items run unattended without monitoring or fear of hurting the AUX battery.
Last edited:
WanderlostOverland
New member
Just completed my dual battery install thanks in large part to ideas from OP write up and YouTube video.
I noticed that the Redarc charger “charge profile” light flickers steady on/off when the 4Runner is off leading to a concern about a trickle load on the battery other than what comes off the fuse box. May add a low voltage discharge.
To OP, do you have a similar experience with your redarc when the vehicle is off?
When the vehicle is running everything operates as expected.
Sent from my iPhone using Tapatalk
I noticed that the Redarc charger “charge profile” light flickers steady on/off when the 4Runner is off leading to a concern about a trickle load on the battery other than what comes off the fuse box. May add a low voltage discharge.
To OP, do you have a similar experience with your redarc when the vehicle is off?
When the vehicle is running everything operates as expected.
Sent from my iPhone using Tapatalk
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