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12vdc charger for 4s lifepo4 portable battery
I removed the Chinese DC-DC and installed the Victron... I dont mind paying for the quality and piece of mind. I like the blue stuff as well.

I have the regular non-isolated version (12/24-10)

The Orion-Tr would be great too, I like that the new models have "smart" bluetooth functions. I would get that if I had to buy another.
From what I can gather the orion-tr is not a cc-cv charger. It is just an adjustable dc-dc converter. So car voltage in and then I can set the output voltage. This is a lifep4 pack so let say I set it for 14.4v. What happens when the batteries are full? Will it just keep everything at 14.4 v no matter what? I don't plan on keeping my battery plugged into my car all the time but I could see it on long trips where I'm using it to run a portable fridge.

The other question I have about this dc-dc business is how the battery reacts when it is charged with a fixed dc input? Lets say the battery is depleted at 12 v (3v/cell) and then I power up the dc-dc converter which is set for 14.4 v. It will obviously put full output current into the cells since they are hungry for electrons. But is it doing this at the voltage of 14.4? Is this considered "fast charging" where you charge at a higher voltage and a CC?
It’s not a CC/Cv charger in that its fully adjustable like a RC balance charger, but it should act similar to one.  You have to treat it like any other pack which gets charged off a “dumb charger” like those hoverboards or scooters.  Just make sure your battery cell groups are of similar capacity and top balance your batteries.  The question and answer will also depend on the batteries you use.

I recommend you get a volt meter and clamp meter and watch it as it charges… it would answer a lot of your questions and probably put you at ease.  You should see the current start to taper off as it get to the top.  The battery is only going to accept what it can and the Victron isn’t going to push out more than the set voltage.  That said its going to push the full current the unit can deliver (CC) unless the unit has current limiting, so make sure your battery can accept the full charge current.  At it hits the set voltage it pretty much (CV) now.  Current will just taper.

If you have concerns, charge it a little lower than 14.4, it’s the benefit of using a DC-DC.  Even if its set at 14v, its not going to over volt the pack.  It’s just going to sit at a state of equilibrium once it gets that voltage. Nothing moving in or out.  Its exceeding the max voltage which is the problem, not keeping it on “float”, especially if that float point is under the max cell voltage.

By the way... my project is also run run a DC fridge in my truck, but I run it off a 7s 24v pack because it can support 12 or 24v battery voltages.  Just an old photo from when I was testing it.  It uses about 350 watt hours over a 24 hour period sitting at 75F ambient.  With a nice lithium pack this thing runs for ages.

Excellent. I like what I hear! I like the balance charger for obvious reasons but I have to open to the case to turn it on. I think I'll be ordering a victron orion for basic dc-dc charging.

Thank you for the help! I understand a bunch of this stuff but then I start to overthink things.

That is the fridge I was referring to. I'm glad to hear how little it uses! I knew that it sipped power but wow... 350w/24hr? awesome! Have you tried the chinese knock-offs?
No, I haven’t tried the off-brand fridges so I can’t speak to their quality or performance.  I did a lot of research before buying and I am very happy with my ARB fridge… it’s a very strong unit, good compressor, efficient.  I have owned it for a few years already and taken it on off-road camping and road trips.

The biggest stress test was when I made a stopover in Las Vegas on my way to Yellowstone.  It was 108F inside the truck when it was parked, and the ARB was holding freezer temps at 13F.  95F delta and it was pretty much running 100% duty cycle.  Never skipped a beat and kept my food in great condition over a 2 weeklong trip.

The "outdoor" sensor was placed in the fridge/freezer.

I love it! Thanks for the help!

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