Writeup on my 48V LiFePO4 power system

[codingparadox]

I finally got around to writing up the power system I've been working on for a couple months. LiFePO4 48V house batteries, dc-dc converters, whole-system Quattro coverage, and more. The time of the 48V system is coming!

https://www.highwind.fun/2021/04/16/...-power-system/

[Seafarer7]

Excellent write up!

[mcarthur]

That's great information! I'll definitely be learning from you.

We have started on a writeup but it's theoretical, unlike yours! Oh and ours includes electric propulsion :

[codingparadox]

I was thinking about adding hybrid electric propulsion if it were viable. Even with 30kWh of power, though, that's SO little drive duration, that it didn't seem worth it. And the amount of weight I'd have to add in batteries to make it viable didn't seem worth it at this phase, with this boat. So I don't think it's gonna happen here.

I read your writeup, and your needs are definitely different from us -- being okay going at 5kn for long periods. With us working full time, we tend to go 9kt or plane at 15kt for a couple hours in the morning, set up anchor or in a marina, and work all day. Then repeat. So I think the hybrid approach doesn't help us a lot right now until we can retire.

Whatever our next boat is, someday, will definitely be a hybrid, whether I have to buy it that way or build it that way.

[codingparadox]

Updated post with a year of extra development:

https://www.highwind.fun/2022/09/25/...ystem-updated/

[LeighC]

Nice diagram, how did you get around the maximum voltage regs on the Blue Seas battery switches (isolators) only being rated at 48Volt DC max & not the charging voltage of around 56VDC?

[codingparadox]

Just ignored it. There's quite a bit of space between the conductors in the internals, 56V is way too low of a voltage to bridge gap it.

[mcarthur]

Fantastic results and writeup - so close to where we want to be (though we'll remove genset and add electric propulsion).

One of the annoying bits I'm doing is bilge pumps, which were never done right. The 3% drop (or better!) and sizeable vessel mean large wires, and being a powercat with bulkheads means 4 pumps per hull - have you found any 48V pumps and water detection switches?

Also which 48V windlass and bow thrusters did you choose? I'd heard Maxwell have a 48V but can't find any other information...

[codingparadox]

Nope, haven't gone 48V for bilge pumps yet. Someday I'll probably redo the whole system and then I'll look for it, but this spring when I poked around, didn't see anything not off Alibaba yet.

Went with this windlass:
Maxwell RC12-10 48V Rope & Chain Windlass 1200W - 12v Solenoid

I ended up getting a tiny Orion-Tr 48-12 to power the solenoids that's mounted next to the Maxwell control box, rather than running a 12V setup over to the windlass.

Thruster I originally ordered the Lewmar 250TT 48V, but after 6 months of waiting for them to finish making it, I gave up and canceled the order. Vetus also makes a 48V thruster set (150/180/210BB) that I would consider, if I get around to wanting to bark up that tree again. Our boat really doesn't have a great place to put it in after the fact though, so I'm not sure what I wanna do with thrusters.