Custom Dual Battery Setup (AGM & Lithium) in a 4-Door Jeep JK

[theksmith 3,827]

12 hours ago, jgaz said:

What gage aluminum do you intend to use on your parts?

 

If you want to design the pieces without the 6” restraint you  are more than welcome to try my Harbor Freight brake I detailed here.

It will handle 16 gage aluminum in lengths of a foot or more.

Even if you leave the <6” tabs it might be nice to bend both tabs at the same time.

 

 

 

 

 

thanks Jim! i think these parts will be too thick though... i'm probably going to use 0.08" aluminum. my contraption needs to support maybe 35 to 40 pounds. i don't have any way to make ribs or dimples to increase the rigidity, so i'm thinking i'll err on the side of thicker than might be necessary.

 

have you ever used ACM panels (Dibond E-Panel is a common version)? there will be one vertical panel that doesn't require any bends, but i'll be attaching a lot of things to it (multiple fuse holders, bus bars, etc.). i'm thinking of using the 1/4" ACM for that panel so i can use short wood/sheet-metal type screws to attach all the random stuff instead of having a bunch of small nuts or rivnuts to deal with. i've never actually held a piece of ACM though, so i'm not sure how it compares to say a 1/4" sheet of acrylic or ABS in terms of stiffness and durability.

 

 

 

 

Edited August 1, 2022 by theksmith

[jgaz 545]

Sorry Kris, I have no experience with the panels you linked.  And you’re right, my brake might struggle with .080 material.

 

I can see where you’d want something that you could screw into instead of through.

 

If you want to fool around with acrylic I have a good size piece of material “in stock” that I trash picked.   It’s at least a 1/4” thick.  You are welcome to it.

The material machines well with woodworking tools but I’m not sure how well it would hold a thread. Might be worth a try.   
It’s translucent and I can measure the piece if you’re interested.

I know your builds are solid but would there be any advantage to having this panel be nonconducting?

[theksmith 3,827]

21 hours ago, jgaz said:

would there be any advantage to having this panel be nonconducting?

 

not not on this one, but good thinking!... i'm actually in the process of making a new hold-down and fuse mounting panel for the OEM battery area and i did need that one to be non-conductive on the bottom, in case it touches the battery terminals accidentally. i'm using a piece of aluminum sheet on top for strength, and then a piece of 1/4" ABS sheet on the bottom to sink mounting screws into and as the insulator. i'm planning to use contact cement and a few screws to hold the 2 sheets together permanently.

 

i think i will try out the ACM for that one panel when i have the rear shelf pieces cut. if it turns out to be too flimsy then i'll just glue an extra sheet of aluminum to it too.

 

as always, thanks for your feedback on my ideas and offers of tools & materials!

Edited August 2, 2022 by theksmith

[theksmith 3,827]

in addition to the charger/isolator and other large gauge wiring near the batteries, i'm going to need to do some minor re-wiring of my accessories so that most can be powered from the house battery.

 

below is my plan for the new wiring. note this only shows the positive wires, and only aftermarket items except where an OEM component affects this system. components are shown in their relative physical locations (for the most part). purple wires are all powered by the starting (OEM) battery. red wires are all powered by the house battery. yellow is 120v shore power.

 

 

notice the winch and air compressor are connected to the starting bank side because they draw so much current. they're only used with the engine running at which time the alternator is providing the primary power for them. if i connected them to the house bank, then the Renogy DC-DC charger/isolator would be limiting what they could pull from the alternator (to 50A) and so they would be depleting the house battery unnecessarily.

 

most items on the house side are constant hot. however, a few components are powered through a relay box, which is controlled by the overhead switch panel, which is only on when the key is in ACC or RUN.

 

the fridge and lithium battery charger (for the house battery) are the only things fed by 120v shore power. the fridge has a built-in switch so that the 120v input takes priority.

Edited August 2, 2022 by theksmith

[WILL E 397]

I took a fairly straight forward approach.   I do have a fridge, a small inverter, compressors, winch, ham radio, heating plates and a few other items.

 

I used the painless dual battery manual setup.  It uses a large solenoid and a three way switch.   Off/on/ and on when ignition in RUN position.  

 

I have a small fuse panel that is connected to a spdt relay.  I wired the relay 'backwards'.  Normally the relay is used to determine where power is sent (one way for normally close and the other way when power is applied).   I did it the other way.  When NC the house battery completes the circuit to the fuse panel.   When the ignition is on the relay is energized and the fuse panel is powered from the main circuit.   This works independently from the dual battery solenoid setup. 

 

 Most of the time the second battery is getting charged when the engine is running (the solenoid is activated)

When I stop the Jeep the fridge, hot plates, etc are all powered only from the house battery which is isolated.   

 

But wait, theirs more!    After doing all of that years ago I picked up a 'Jackery' portable power system.  I have the 240.  There are various manufactures of these.  It has a built in inverter, usb ports and a 12volt power port.    So what I do now is I connect the high draw items (fridge) to the Jackery and then plug the jackery into the house battery system for charging.   It also can be charged with a solar panel.   The small 240 powers my ARB for over a day without a charge.   And since it is portable I can bring the fridge/hot plates to where I am hanging out.  

 

  

 

[theksmith 3,827]

the lithium battery is supposed to be delivered today. i'll double check its dimensions and then can order the parts to be cut for my rear "battery shelf" bracketry.

 

everything else is pretty well planned out now too... i think! i'm sure changes will be necessary once i start putting the real pieces together.

 

 

oem/starting battery power distribution (engine bay)

 

i need to cleanup my existing fuse panel a little. it started out like this a few years ago, but has grown over time and gotten messier:

 

 

i'm sticking with the Cooper Bussmann LMI1 Midi fuse holders and mainly just need to add one here for the dual battery setup (there will be a whole other panel in the rear for the house battery). i'm going to make a new oem battery hold-down that doubles as a mount for these fuses, and change to military-style battery clamps. this will be the new configuration up front:

 

 

 

house bank power distribution panel (rear)

 

my mount for the house battery will have a vertical panel to hold the Renogy charger/isolator along with all the "house bank" fuses, wiring, and related modules. it will be accessible by folding down the rear driver-side seat. here's my plan for that:

 

 

Edited August 26, 2022 by theksmith

[theksmith 3,827]

glad i waited to double check the battery size! the listed dimension on Amazon for this Dobelay 100AH are smaller than reality by more than a 1/2" each direction. it's actually the same size as the Power Queen Premium 100AH i mentioned earlier - about 10.3" x 6.5" x 8.3". fortunately i designed my shelf mount a little big just in case and so i only needed to modify two parts' drawings to move the hold-down bolt holes.

[theksmith 3,827]

the custom pieces for my rear shelf mounting area are cut and have shipped - they should arrive tomorrow!

 

 

shore charger (120v)

 

i decided on the Victron "Blue Smart Charger 12 | 17 (IP67)" for a shore-powered house battery charger. nearly anything Victron makes seems to get good reviews. i've only played with this a little so far, but i'm impressed with the Bluetooth app already and the build quality seems good.

 

 

the app seems very stable, which should be a given, yet a lot of cheaper BT devices just can't seem to get it right and have trouble even staying connected. it has more info than most people will ever need:

 

 

you can choose a basic charging profile...

 

 

but the main reason this thing even has an app is so you can configure your own charging profile to match the exact recommendations from your battery manufacturer. selecting expert mode and then a "custom" profile will enable all of these settings:

 

 

on last thing i like is that there is just a single main Victron app and you can manage all of your Victron Bluetooth enabled devices with it. that's much preferred, IMO, versus needing to download a different app for each device. because of this, i'll probably go with their BT SmartShunt for a battery monitor when i'm ready for that piece of the puzzle.

 

Edited August 10, 2022 by theksmith

[jgaz 545]

I’m looking forward to seeing your mounting pieces. 
I have a feeling they are going to take even one of your projects to the next level

[theksmith 3,827]

parts arrived from SendCutSend!

 

 

that ACM panel turned out to be plenty stiff for this project. i'd say it's slightly more rigid than the same thickness (1/4") of high-quality plywood. in the photo above there's still a protective film on it, the actual finish is matte black.

 

the little magnetic vise brake in action (on an old POS Harbor Freight vise).

 

 

 

this 0.08" aluminum is about the max thickness for it, at least for a 5" wide bend. i had to really put some effort into turning the vise handle. also, at a full 90* the outside of the bend is starting to show a little bit of fracturing due to the tight radius.

 

 

parts all bent:

 

 

did a quick test-fit of the main pieces. a couple places are a little tight and one spot might need trimming, but overall i think all the parts can be used as intended.

 

 

 

 

there's also a lower support piece not shown in the photo above.

 

here's that ACM panel which will hold all the fuses, bus bars, disconnect, etc. (just set in place for a test fit):

 

 

 

these parts cost me $160 total, which seems like a decent deal for a completely custom mount. that similar shaped MORyde ammo can bracket goes for $200.

 

Edited August 12, 2022 by theksmith