I ended up with an EcoFlow Delta 3 Plus and installed their 800w alternator charger. Between the 500 not being any smaller, and my use case, I figured just go with the higher capacity.
Part of what convinced me to do that was checking whether the HV/HC input on the EcoFlow Delta 3 Plus were wired directly to the battery. If so I'd hope to run a plug there that could provide DC to my LiPo charger. Turns out those terminals don't show anything with a multimeter, which means they are metered/controlled somehow, and that hack wasn't going to work.
Turns out the Delta 3 inverter is really efficient anyway, using less total Wh to charge my LiPos a given mAh than the same charge cycle on the Delta 3's USB-C outlets. I was really surprised to see this.
So the question was where to put it.. I don't have drawers like so many here, and having the brick be out of the way is very important for my *drive, shuffle a few things around in the truck to sleep on the road, drive* method of traveling. The fridge already can't go in the semi-permanent spot for my old cooler, so that has to get moved. Which slows me down.
Plus between trips the whole thing will get removed, so mods to the vehicle to get it to mount solidly aren't as acceptable.
I settled on a chunk of decent plywood cut to fit behind the passenger seat to act as a base. Strap the Delta 3 unit and alternator charger to that board as far rearward as possible to minimize the impact to positions of the co-driver seat, it has a floor vent pointed at it, and it turns out the cable run to the battery is within 2 inches of being absolutely perfect.
I used a battery pad from my FPV drones called Ummagrip between the charger and delta to prevent rattling/shifting. It's remarkably stable.. I'll probably switch to a 2" cam buckle or ratchet strap eventually for more security in the event of an accident.
The noise attenuators or whatever the lugs near the ends of the big cable are HUGE. For some people's installs things would be vastly simpler if those things were smaller or absent. No you shouldn't need to string that end through bulkheads or grommets or whatever, but if trying to maximize packaging they could be a problem for some.
And not sure if the size of the alternator charger overall comes across. You can watch install vids online.. it's not small.
I wanted to minimize mods to the vehicle.. Between one new hole in the passenger side firewall harness grommet, and this one cut-away from the small removable portion of the B pillar trim, I can put things back together in the future very easily.
It didn't move at all over a ~3k mile trip last week. I'll find something to put on the plywood to protect it. And need to speak with EcoFlow about why the charger routinely won't start saying "voltage below limit" when I've got that limit set to 12.9 and the app will sit there and display 13.2 or whatever. When that happens the only way I can get it to turn on is to go into settings and run the start voltage down to 11.5 or something, it will start, then I can raise it to 12.9. I do think if I wait long enough it'll eventually start without intervention.. but it's odd behavior and I intend to see what EcoFlow has to say about it.
The unit itself was invaluable for this trip.. running my fridge, and charging a few LiPos a day depending on what I found to fly. The previous trip I had to pop the hood and use clamps on the battery to charge them at any reasonable rate. Which meant being stationary. Huge advantage here. I'm really happy with it overall.
I will say though.. anyone getting one of these needs to go in and tweak the auto shut down parameters. My fridge shut off 3 nights in a row as various parts of the system timed out due to the fridge not drawing current for X time as ambient temps were so low. I settled on a 24Hr global timeout.. after that no issues. And the 12v socket adapter for the IceCo fridge did great for all of that mileage.
Last thing.. charge current. For AC charging you can just tell the app X watts, but when using the Alt charger you have to set it up in Amps. I didn't want to hammer my alternator by using the default 800w, even though ours is in a peak Amp category that it's technically allowed. 500w sounded like a nice balance between fast charging and not leaning on the alternator too much, so I went with 40A. This ran around 530w and did great for my trip. I could probably have lowered that to around 300w and my driving during the trip easily kept the bank topped up.. I'll probaby do that next trip. Either way it's very easy to configure this stuff in the app, and needless to say the 800w capacity of the alt charger means you have a ton of overhead if you need it.
