Dual Battery peer check

Hey everyone! I'm currently trying to get started on my dual battery install. I've attached a very crude diagrams of what I am thinking of doing. I already have a SOK 24V 100Ah LiFePO4 but I wanted to make sure I'm not missing anything before I buy the rest of the parts.

My plan is to put a Victron Orion-Tr Smart Isolated DC-DC Charger (12Vin/24Vout/360W) in the engine bay next to the fusebox on the driver side. One big concern with the charger in the engine bay are the temps, the max operating temperature of the charger is 70C. I'm not sure if it will get that hot in that area or if I will have to move the charger inside. I would rather not have it in the trunk as I would have to use a much larger gauge cable from the starter battery and deal with a larger voltage drop. I will probably do a relay box relocation according to the PowerTray website and either use their tray or the C4 Fab one. There is plenty of room on the passenger side of the engine bay but I would like to keep the wires short. I was considering putting it on top of the fusebox but the charger gives off a good amount of heat as well. If anybody has a better solution, please let me know.

I used this chart from IH8Mud (Original from Blue Sea) and the circuit wizard from Blue Sea plus some extra safety factor. The charger will connect to the starter battery with 10AWG wire, maybe 12AWG since the run is so short (and I have some spools already). Between the starter and charger will be a 30A Blue Sea circuit breaker. The charger to the battery in the trunk will be connected with 8AWG wire and will be routed through the firewall and under the door sill covers. There will be a 40A Blue Sea circuit breaker next to the output of the charger. Not sure where I will drill holes for the wires in the trunk yet, but that isn't urgent. I will add Anderson Powerpoles at the end by the aux battery. The aux battery and inverter will be connected with 2/0AWG wire and a 200A Blue Sea circuit breaker. I will also add some Blue Sea USB and 12V DC ports to the aux battery output as well. I'll most likely use a 250A busbar and 12AWG wire to get power to the ports.

Any advice is welcome!

 

And how did it turn out? Getting ready to do this in the next week or two...why the batt in the back? Thought the default was pass side firewall...

 

because that type of battery won’t survive under hood temperatures

 

Thanks...didn’t know that...I’m using a 125ah AGM for my house battery...been using them on my shop solar system for 3 years now and really like them...

 

AGM is nice because it’s much more robust. The problem is it’s very heavy and you can only use half of its amp hour rating. 100ah AGM gives 50ah of usable power, 100ah LiFePo4 gives you 100ah of usable power, getting usable 100ah out of AGMs is like 17 trillion tons of weight.

 

Hey! Sorry for the late reply. Agent_Outside is correct with the reason why I'm keeping it in the trunk. There was a Wanderlost Overland video which helped me decide not to keep it in the engine bay. I am still waiting for room in my budget for the rest of the parts. Currently I still need the inverter, wires, terminals, and circuit breakers. I will probably buy them after the holidays or during the spring. Another issue I've found is that the engine bay accessory mounts I've found from PowerTray and C4 Fabrication do not have the correct hole locations I need to mount my DC-to-DC Converter so I'll have to get in contact with someone who can drill them. I'll definitely update this or make a new post and link this one once I finish it though! Let me know if you want high resolution pics of the install!

 

Here’s the link to mine, it may help with ideas for the C4 tray.
https://aguyagirlandatrail.com/custom-power-distribution-system/

the thing that seemed off about your plan is using a 24 volt battery, unless you don’t plan to fun any 12v accessories.

 

I have a similar setup, but I located my Victron DC-DC charger on top of my battery case (behind the driver's seat). I've noticed its throughput is very sensitive to temperature. It seems to throttle pretty aggressively when it gets hot (like when I throw a jacket over it). So...I try to keep it cool with good airflow around it. Here's my setup: https://www.4runners.com/threads/my-lifepo4-battery-setup.24070/#post-313486

 

Hey, thanks for that link. I ultimately went with the PowerTray since it was aluminum and easier to drill. I did like the way the C4 mounted better though. Most of my devices are 12-24V so I figured I could be more efficient using the high voltage (I[squared]*R losses) and getting a 24V to 12V converter for the stuff that can only use 12V (like the battery heaters I've seen). I do like that AC to DC charger you have set up, I would like to do the same but I will probably go with a Victron BlueSmart IP22 since my battery is in the trunk.

Thank you for your insight! I actually used the info in your post to design my setup so I appreciate that! I was able to mount the Victron charger onto the PowerTray in the engine bay, so far it doesn't overheat and I assume the aluminum tray helps dissipate the heat Also is that breaker panel flush to that trim? I ask because I considered that as well but the trim was slightly curved.



I recently finished my dual battery mod as well, although it still needs some tidying up. I have been very busy but I will post my write up soon!

 

It doesn't sit flush, but it's tough to notice unless you really peek from the edge. It seems nice and stable:

https://imgur.com/a/TGwurz7