Advice Needed for Dual Purpose Li/CCA Battery OV Setup

[windseeker]

Hey all, this is my first post so please take it easy on me! My goal is to make a dual battery, 200 w setup for my 2005 4Runner. I've read mixed reviews on the Dakota Lithium DP batteries but I decided I'd give it a shot. I realize there were cheaper options out there but I wanted to go with something turn key because of my limited experience. Please know this is not sponsored by Dakota Lithium in any way. I simply found their products interesting and their support staff really helped me a lot so I decided to try it out. Here was my methodology behind the purchase.

Pros:
-Dakota Lithium DP batteries have more AH than AGM or SLA
-They are also lighter
-If they perform as advertised then CCA is not an issue

Cons:
-Price
-Alternator draw (this is a big issue but I believe I have a solution)

Here's what I bought:
-Two 135AH dual purpose Dakota Lithium batteries (these are rated at max A of
-Dakota Lithium 200W solar kit (I got this because it was very light and allows me to have lots of flexibility on my rig)
-Dakota Lithium 1500W inverter
-Victron MPPT 75/15 solar charge controller
-Victron Orion Smart 12/12 - 18A Isolated DC-DC Charger (I was told this will drastically improve alternator life and this is my solution to one of the cons)

What do I need:
Obviously I need more than the above to finish but my question is what? Specifically what fuses and gauge wire do y'all recommend? I will probably be running the charger and controller to the rear of the vehicle so that's about 12 feet of wire needed.

Diagram:
Would anyone be able to assist me with a diagram? I am a very hands on learner and I can easily do all the connections but I believe this may be the best way for me to learn (actually doing the work) with the proper diagram and instructions.

More Info:
Pending feedback, I'll be mounting my house battery in the passenger corner of my 4Runner. There is plenty of space and the load will be distributed nicely. I intend to mount my panels on top of my aluminum shroud roof top tent so they can naturally pivot with the tent as it opens so I will need to account for this in the length of the solar connecting wire.

Thanks in advance everyone!

 

[AnarchyJet]

I don't get the dual purpose batteries? Are you replacing the start battery with one of these and then adding a second in parallel?

 

[windseeker]

I don't get the dual purpose batteries? Are you replacing the start battery with one of these and then adding a second in parallel?

Correct yes. They have enough CCA to function as a starter. So I’m putting starter battery as one of the 135AH dual purpose and adding a house battery for the same.

 

[AnarchyJet]

Got it. Then you are going to need wiring diagrams of the starting and charging circuits of the Truck. This is going to be hard to do because the alternator is tied directly to the starting battery. When the engine is not running the DC is supplied by the battery. Once the engine starts it is supplied by the alternator and the batt is recharged. Simply putting the DC-DC between the alt and batt will only give you 18a to run the whole truck which will slowly drain the battery from running.
The other issue is load sharing between paralleled batteries that are not right next to each other. usually you put the + lead on one batt and - on the other.
If possible I would return the 2 Dakota batteries. Leave the FLA starter batt and truck DC system alone. Add a 200ah LFP house batt connected to solar and the dc-dc. I would return those solar panels also, $800 for 200w is criminal.

https://www.amazon.com/Alrska-Flexible-Monocrystalline-Semi-Flex-Off-Grid/dp/B0B4KTQTB3/ref=sr_1_2_sspa?crid=YIUUW8ORE17C&keywords=flexible+solar+panels&qid=1665771399&qu=eyJxc2MiOiI2LjYyIiwicXNhIjoiNi4zNyIsInFzcCI6IjQuOTkifQ%3D%3D&sprefix=flexable+solar+panels%2Caps%2C103&sr=8-2-spons&ufe=app_do%3Aamzn1.fos.f5122f16-c3e8-4386-bf32-63e904010ad0&psc=1

 

[windseeker]

Thanks for the insight. I’m new to this so there’s a lot I don’t anticipate.

I attached a photo of rough wiring diagram I got from Dakota Lithium. What do you think? It shows wires into the starter first which should solve the issue you describe with the starter draining right?

 

[camelCase]

It sounds like you intend to use one of the lithium batteries as the starter battery? If so, it's customary to isolate the starting battery from the house battery so that you don't end up stranded somewhere because you accidentally left a load on that ran all the batteries down. My suggestion is if you have room to mount both lithium batteries in the back that you keep your lead acid under-hood starter battery.

One big reason for this is that even though you can use those Dakota batteries as a starter battery, you still can't charge LiFePo4 batteries when they are under 32f which really limits when you can drive the car. Check the section titled "Operating Temperature" in the specs.

DL+ 12v 60Ah Dual Purpose 1000CCA Starter Battery Plus Deep Cycle Performance

Twoin pack, 12V 60Ah multi propose 1000 CCA lithium starting dakota battery plus for marine engine, automotive, deep cycle use. 4x longer 11year lifetime.

dakotalithium.com

 

[windseeker]

Yes that’s right. It is a dual purpose starter battery. Please reference the link in my first post.

Yes, I agree it is customary to isolate the two which is why I intend to use a DC-DC charger and isolator from my first post (I’m actually looking into Renogy as it might be better). If you look in overland battery vehicle set ups most of the folks are running a dual battery connection with the alternator and some are even using a manual switch which is not recommended whatsoever. They are typically using AGM or SLA. The dual purpose batteries I have are Li that have CCA. They’re lighter which helps a lot on my rig.

Also yes I agree, that most Li batteries will not allow you to charge below 32 however it is becoming more customary for some battery cases to include a heating element with a temperature sensor. This is common with Battle Born and Dakota Lithium also uses the same technology. Therefore you can actually charge to -20°F as opposed to the 32Ft hat you mentioned. See link in first post and read battery description.

I mentioned the isolator on my first post and it is a necessary component. I know this is a setup that will work flawlessly because I’ve seen it done so I’m not reinventing the wheel. The issue is that a battery like this hasn’t been available to consumers until recently and not even overlanders have pieced it together en masse. The dual purpose batteries in parallel allow me to have 270 amp hours all within the hood of the 4Runner since I don’t have to deal with an SLA battery that I can’t drain past 50%. That is an immense amount of space savings and a ton of energy that I have access to where I don’t have to put it in the rear of the car. I also save weight as two of the batteries weigh about the same as one SLA battery.

My question simply lies on help with a wiring diagram and some potential step-by-step instructions.

 

[windseeker]

It sounds like you intend to use one of the lithium batteries as the starter battery? If so, it's customary to isolate the starting battery from the house battery so that you don't end up stranded somewhere because you accidentally left a load on that ran all the batteries down. My suggestion is if you have room to mount both lithium batteries in the back that you keep your lead acid under-hood starter battery.

One big reason for this is that even though you can use those Dakota batteries as a starter battery, you still can't charge LiFePo4 batteries when they are under 32f which really limits when you can drive the car. Check the section titled "Operating Temperature" in the specs.

DL+ 12v 60Ah Dual Purpose 1000CCA Starter Battery Plus Deep Cycle Performance

Twoin pack, 12V 60Ah multi propose 1000 CCA lithium starting dakota battery plus for marine engine, automotive, deep cycle use. 4x longer 11year lifetime.

dakotalithium.com

I appreciate you trying to point this out but the key difference between the 60AH and the 135AH with Dakota lithium is that the 135AH does include the internal heating element which is why I ultimately decided to use these batteries as opposed to the 60 AH dual purpose