Dual Battery Setup for my 80 (2 Viewers)

[SeanLX]

I would definitely not use a Blue Sea ML-ACR (again). I switched from deep cycle to an LiFePO₄ lithium battery. 100Ah is around $200 now. Check out Will Prowse on Youtube for reviews on which ones are built well.

It's really nice to have that extra capacity of lithium and it's a lot lighter. Fridge went from 1-2 days to more like 4 days solid without starting the cruiser.

I was really disappointed when I first put in the Lithium. The resting voltage of the lithium was above the cutoff / combine voltage of the SI-ACR Automatic Charge Relay I'd been using for years. I like the quality of the Blue Sea stuff but I called them and there was nothing to do to make that work with Lithium.

This is what I swapped to instead of the Blue Sea

https://www.amazon.com/gp/product/B08X6HH5GW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

There are probably other options and I'm interested in alternatives if there anyone has other suggestions. This one has been good and has solar input but options are good.

One problem I am having is temp. I made sure to get a lithium with lo temp charging protection but that means when it gets cold it shuts off to protect itself. Some 12v heat pads are on my short list to add next.

I also have a portable power station (Ecoflow) inside the cruiser but having the extra 100Ah under the hood is nice.

 

[CrabCake]

My rig came from the PO with a dual setup...and the IBS-DBC dual battery controller. One thing that I especially like about this one is that it shows your voltage on both batteries, including when charging. I did have to use it a couple of weeks ago to jump my house battery that I knew was getting weak...it was a perfect time to test it in the garage after sitting for a week, and worked flawlessly to boost like it was on a good primary battery.

I run a larger fused wire to the back on the drivers side for light loads and a circuit breaker controlled heavy wire from the extra battery on the passenger side (for fridge, extra lights, etc.). This also powers my ARB compressor for the lockers and back up air if my Power Tank is not in the truck or low.

Here's an interesting article from the IBS site that I came across....compares a few systems and gives pointers about each setup.

http://ibs-tech.ch/fileadmin/ibs-tech/pdf/pdf_Artikel_Print_Media/English/Dual_Battery_Systems_-_Wheels_Afield.pdf

 

[CharlieS]

I guess I'll jump into this conversation as well. When I wired up my dual batteries I used a drawing I sourced from a out of business vendor. This schematic allows you to wire in a Blue Sea ML-ACR and with the dash mounted switch. The Blue Sea ML-ACR allows you to jump the batteries and self jump yourself if your starting battery does die.

View attachment 3812591

Then I was given this rough drawing for how to wire in a the ML-ACR with a Red Arc DCDC charger. This drawing includes solar option as some Red Arc DCDC chargers have the option for a solar hook up. The nice thing about having the solar option is that the Red Arc will pull power from solar first then the alternator. In no way am I am assuming the Red Arc DCDC charger is running full time, if it does adds the comfort of knowing your batteries are charged.

One last thing as far as connecting the two batteries via the ML-ACR, you will want to purchase (2) Blue Sea fuse block terminals, with a separate 200 AMP fuse. They will be mounted to the threaded post/MIL-Spec automotive terminal kit on the positive side of each battery.

View attachment 3812623

View attachment 3812589

This schematic was sourced from Red Arc's website for their BCDC 50A Alpha charger. Most of the wires you see are included in these kits if I recall or can be sourced from Red Arc or a Red Arc dealer.

View attachment 3812618

To address your the things you are wanting to run off different power sources here are my thoughts and if anyone disagrees please feel free to correct me:

WARN Winch - run it off your starting battery. One thing I would recommend in winching situations is to get yourself the handle throttle. The hand throttle allows you to raise the RPM and increase the charge rate of your alternator while winching. You can also wire in a switch to kill power going to the winch, some say it is over kill. I personally do not have a kill switch.
53L Refrigerator - the fridge can be run off a power source via an inverter in the back, if you plan on using the plug. Depending on the fridge you can get a hard wire kit that you can use the fuse panel to source power from. Below is a picture of a 1/4 panel with some extensive wiring. The fuse panel you see in this picture can be sourced from @Delta VS pre-built with the relay on the side. The long bars you see ground cables going to are called bus bars, they provide you with a common ground source for multiple items. This will make your life easier when tracking electrical issues.

View attachment 3812592
USB ports in front and rear - in the picture above you can use a 12 slot fuse panel the again is available from Delta VS. You will power your USB ports from here or you can add a second fuse panel mount in the center console
Several Led lights for camping - again these LED can be ran from a power source similar to the fuse panel above.
Diesel Heater - Diesel Heater doesn't need an external power source if I am correct. Diesel is the power source and there are some great options out there for some vehicle mounted solutions.
Misc stuff
Be able to start if one battery is dead - I go back to the Blue Sea ML-ACR and Red Arc DCDC chargers that I mentioned above.
I also have an Anker C1000 Power Station that will need charging - doing an inverter will allow you convert power from you battery to power/recharge this power station re-charge camera batteries, etc. The size of the inverter limits what you can run, if it was me I would run no less then 1500 watt inverter.

Also, use the largest batteries you can fit in the stock box with the longest reserve capacity and stay with the same group size for both. Land Cruisers call for either a group 24/24F or you can even run a group 27/27F. I run 2 group 34 AGM batteries in my 80. The starting battery is a Interstate MTZ-34R and the house battery is a 34M-AGM from Interstate as well. The house battery I would recommend having a deep cycle battery as there is a greater demand on that battery. The bad thing about Lead Acid batteries compared to Lithium, lead acid can only be discharged 50% before you have to charge or it has to be charged. Lithium per some sources say you can discharge them down to 10% and they do have longer AMP hours meaning they go longer between charges. But lithium batteries can be expensive, quickly looking at both Battle Borns site run $750 - $950 and the Red Arc batteries is $1800.

And before I forget a second time, get yourself a some type of circuit breaker too, minimum of 150 amps. That way you can cut power to the back when you are not using those items or parking the rig for an extended period of time so there is no extra draw on the power source causing dead batteries.

If you have any questions feel free to contact me via DM and we can talk there or via text.

Most of if not a lot of the parts I have mentioned can be sourced either from Delta VS or Amazon or Red Arc

I would recommend sizing the circuit breaker to the circuit. 150 amps is a pretty large draw.

 

[CrabCake]

I would recommend sizing the circuit breaker to the circuit. 150 amps is a pretty large draw.

I'd agree with this too...mine is a 50a and it's never been a problem. Unless you are running 2 gauge wire to the back, stuff will probably be melting before a 150 trips.

 

[peytonkristen]

A few weeks ago I posted about getting power behind the second row of seats which has led me to realize that I definitely need the Dual Battery Setup.

I have spent many hours over the last few days browsing the FAQs and the many posts about this topic, some of that info goes back 20 years or more. Some of the older stuff seems fairly simple and then there are the newer, fully involved systems. I've read so much and seen so many things that I now have no clue what is best or what I need.

This is what I will need to power/charge:
WARN Winch
53L Refrigerator
USB ports in front and rear
Several Led lights for camping
Diesel Heater
Misc stuff
Be able to start if one battery is dead
I also have an Anker C1000 Power Station that will need charging.

So far, I have a new OEM battery box for the auxiliary battery and need to get a bracket to relocate the washer bottle.

Any advice would be appreciated for what I am going to need as far as wiring, controllers, fuses, and type of battery. Diagrams and links to currently available products would be great too. Thanks!View attachment 3812234

So after reading all of the replies, and since I have an Anker power station, I think I will abandon the dual battery install for now. I still want to run power back to the rear quarter panels (see the attached concept drawing). My Power Station will be used to run the fridge and other big draws when camping. The Anderson Connectors will be for charging the Power Station and running the fridge while traveling. The USB ports will be used for small draw things like phones, etc. at any time. I haven't looked into sizing for wires or anything yet. Let me know your thoughts and advice. Thanks for all the replies and advice!!

 

[CharlieS]

So after reading all of the replies, and since I have an Anker power station, I think I will abandon the dual battery install for now. I still want to run power back to the rear quarter panels (see the attached concept drawing). My Power Station will be used to run the fridge and other big draws when camping. The Anderson Connectors will be for charging the Power Station and running the fridge while traveling. The USB ports will be used for small draw things like phones, etc. at any time. I haven't looked into sizing for wires or anything yet. Let me know your thoughts and advice. Thanks for all the replies and advice!!

View attachment 3813077

Looks great.

I have an AMI fuse between the battery and the circuit breaker, but it probably is redundant. Maybe some of the more knowledgeable electrical gurus can weigh in.

I used this Bluesea 5025 subpanel in the cargo area of my 200 (and my boat, lol). I like that it has a ground bus too. I ran the ground to a factory body ground point in the D pillar.

Be sure to size your ground to match your 12v positive (don't scrimp on wire size ).

 

[98 SNAKE EATER]

I kept mine pretty simple using a big 500amp solenoid and an adjustable timer relay

Main concern is that I wanted to be able to self emergency start in the event of a dead primary battery and still have ALL accessories (front/rear winches and a $#!t ton of lights) be able to work on the secondary battery alone in the event of a total primary battery failure

Most battery isolator kits are limited to 250amps or so, which isn't enough when a winch can easily double that on a hard pull

 

[troopysahara]

Hello,


i have been having some issues with my dual battery system that i hope someone can help with.

I have a standard lead acid 90 Ah as a starter battery in my 78 series troopy. connected via the IBS dual battery system, to an AUX 80 Ah lead acid battery. the system works fine and connects the two batteries when i have the engine running and the relay feels the 13.5V charge from the alternator.

I then added a cheap standard PWM solar controller connected to a 150W solar panel on the roof. The solar controller was connected to the AUX battery.

When i turn off the engine the IBS system isolates both batteries, however when i have enough charge coming in from the solar system the IBS links both batteries and charges the starting battery as well, displaying that both batteries are fully charged. yes this all sounds great till now haha.



However once i replaced the the PWM controller with a VIctron 100/20 Mppt controller the system has begun to act a little funky. in addition, I run all my loads off the load output of the MPPT controller, just to have an idea of how much power im consuming (just have a fridge and one led light running of this)



once I plug in my 150W solar panel, connected to my Victron mppt 100/20 solar controller to my aux battery,The IBS begins to feel a charge (indicated on the left bottom led 13-13.5V) but no linked led on. Then the charge drops and the relay kicks in and the linked led comes on but no charge. And it repeats this cycle every 30 seconds or so. I checked all my battery settings on the Victron app and the data seems to be correct to those set for a lead acid battery.


Now my start battery has died for some reason after not starting the car for 2 days! using an avo meter, the start battery reads around 11.5V and the aux battery is reading 13.5V, which is basically the same figure my Victron app is showing for my aux battery which is 13.7V at a float state of charge.


I even tried the link function off my IBS system and it is not able to jump start the starter battery. I have even used jumper cables between both batteries and still nothing, even tried hooking up to another car's battery, still no hope. I am starting to feel like it could be a faulty start motor on the 1HZ.

I dont understand why my IBS system is acting this way once i connected the mppt controller, and now i dont get why my start battery would die.

any help or recommendations would be greatly appreciated!