DC-DC and Trickle Charger on same circuit question!

[Vision.Urban.Reed]

Hello, I am stumped on a certain question here, and I could use some help with my thinking.
I drew a simplified/stripped down diagram of this specific section of my electro system to represent the heart of my question. Here it is.

Essentially, I want to understand how having a B2B charger and a trickle charger on the same system may or may not present a problem. I am using the equipment in this photo, except for the 12v lead acid battery, the one I have is just your average 12v LA, but not the one in this photo. I have all the correct quality cabling, quality terminals, and all the right fuses etc.
Walking through the diagram:
1. Starter battery ---> orion 18 amp DC - DC.
2. Orion ---> bus bars ---> fuses of hub
3. Hub ---> house battery, charging the house battery. Great. Everything so far is straight ahead.
4. House battery ---> hub.
5. Hub ---> trickle charger (following the manual, trickle charger wired parallel to double the 2.5 amps to 5 amps, as seen in diagram)
6. Trickle charger ---> starter battery
does this create some kind of potential danger of any sort? Manual of the trickle charger states that charger is only charging when the house battery is being charged. This worries me, because the house battery is being charged with the B2B charger, which therefore would allow the trickle charger to charge the starter battery, opening up, to my mind, this electrical loop that I might be more worried about than I need to be. +/- 18 amps passing along the green arrows in the diagram, +/- 5 amps passing along the yellow arrows in the diagram. I am thinking about this like a network of rivers and water, but I think I need to adjust my thinking towards a different and better suited analogy.

I have been making thick battery cables and running all the cables today, my mind is kooky, so maybe I just need to sleep on this and it will make more sense later.

Thank you for any reassurance you could send my way.

 

[MisterSandals]

2. Orion ---> bus bars ---> fuses of hub
3. Hub ---> house battery, charging the house battery. Great. Everything so far is straight ahead.

This sounds overly complicated. I've installed an Orion before and the output went to the battery directly rather than to a central distribution center (for simplicity if nothing else).

I've pondered your drawing a few times. Knowing that the Orion will only charge when the starter/engine battery reaches a certain voltage (~14V).
So when engine not running, the house battery trickle charges the starting battery.

+/- 18 amps passing along the green arrows in the diagram, +/- 5 amps passing along the yellow arrows in the diagram.

Yes, the 18A when engine is running. But at that point the 5A trickle charger would see 14V on the starter battery and "likely" not be pumping 5A back into the starter battery.

I "think" you're good to go as diagramed but i like distinct wiring from chargers to batteries rather than common distribution centers. Its certainly easier to think about and get the wiring and fusing right (for 18A).

You can check the current flows with a clamp meter with the engine running and when not running to verify this is working as you'd expect.
The key is knowing the Orion looks at ~14V to start (unless you're using the IGN input which would give you a little more actual control but i found the auto voltage sensing to work great).

 

[Vision.Urban.Reed]

This sounds overly complicated. I've installed an Orion before and the output went to the battery directly rather than to a central distribution center (for simplicity if nothing else).

I've pondered your drawing a few times. Knowing that the Orion will only charge when the starter/engine battery reaches a certain voltage (~14V).
So when engine not running, the house battery trickle charges the starting battery.

Yes, the 18A when engine is running. But at that point the 5A trickle charger would see 14V on the starter battery and "likely" not be pumping 5A back into the starter battery.

I "think" you're good to go as diagramed but i like distinct wiring from chargers to batteries rather than common distribution centers. Its certainly easier to think about and get the wiring and fusing right (for 18A).

You can check the current flows with a clamp meter with the engine running and when not running to verify this is working as you'd expect.
The key is knowing the Orion looks at ~14V to start (unless you're using the IGN input which would give you a little more actual control but i found the auto voltage sensing to work great).

Superb, thank you MisterSandals. I will check these points as you have recommended, and return here with results once I have reached that stage, in the case that it could help someone else in the future. I like your thinking about direct to battery simplified connections. I need to think about that. I guess my original thinking was, oh hey, what a deal, I can have all my fuses and negative bus bars in one place. I was not really thinking about the added wiring/terminal cost and added complexity at that point of my (continuing) beginner stage. Ok, I appreciate your reply!