H376 lithium and new inverter

[aaronaxvig]

When we acquired our boat a few months ago it had a Xantrex Freedom charger/inverter, a large house battery, and a normal sized starting battery. Alas the house battery, even though it was large, was a starting battery, not deep cycle. Not going to meet our needs for liveaboard.

Then I tried to see if the inverter worked. My first attempt fried a GFCI outlet in the kitchen. Another attempt let out a pop and a burning smell from the inverter. It always claimed to be overloaded when trying to run the inverter.

Maybe it would have worked if I had operated it exactly correctly, so I'll take some of the blame (didn't do forensics on the wiring before I tried it out). But it was wired spectacularly incorrectly. The inverter 120V output was wired directly to the output lug of the Outlets circuit breaker on the 120V panel. So I believe the intention was to turn off all of the 120V breakers and then run the inverter to power the outlets. It could be very exciting to have 120V outlets powered even when the Outlets breaker is turned off! And lastly, the 120V feed to the inverter was supplied via the Battery Charger breaker on the 120V panel (with shore power going directly into the Shore Power A bus of course).

The manual said that the recommended way to wire it was to run the shore power connection directly to the 120V input on the charger/inverter. Then power all the 120V loads from the inverter output (actually bridged to shore power when shore power is connected) and optionally connect some loads like the water heater to the second 120V output on the Xantrex that is only live when shore power is connected. At the time I was just getting into Nigel Calder's electrical book and that recommendation matched what he described as a "DC system", which I did like.

Continued in next post...

 

[aaronaxvig]

Victron also had a whitepaper about a "DC system" that was a pretty good read. I started looking into Victron stuff and liked what I saw. Mastervolt seems good too but harder to just buy the pieces that you want online (if I remember correctly, could be totally wrong). So after a couple planning sessions I started ordering.

BTW, the overall goal was to have a system that would be able to supply us with enough power to run the electric kettle for coffee in the morning, occasional microwave use, and even use an InstantPot or bread machine on sunny days. And if possible for even more luxury be able to just leave the inverter on most of the time. And all of this when we are living aboard at anchor.

I almost went with the Victron LiFePo batteries so that I would have the most tightly integrated system possible, but they were too much of a premium over the BattleBorn ones.

Parts:
4x 100Ah BattleBorn batteries
1x Victron MultiPlus 12/3000/120 charger/inverter
1x Victron BMV-712
1x Victron Color Control GX
(Also a Victron MPPT solar charge controller that I will describe in my solar post)

At the time of install we were living on the boat on the hard. So we spent most of the day with all power shut down while I crimped many many ends on very large wires. I put all the batteries in parallel with identical length cables to a negative bus bar and to the positive bus bar via a 200A circuit breaker for each one. All those batteries, bus bars, and the BMV shunt fit in the forward compartment under the port-side couch. I filled in the bottom of the compartment with some scrap marine plywood (from bedroom cabinet destruction that I described in my composting head post) until it was level with the ledge of the fiberglass curvy piece along the front. Then I cut a board to lean against the hull and on that I mounted the breakers, bus bars, and shunt. Everything is jammed in there moderately tight but it wasn't terrible, just need a little patience.

In the middle compartment I put the charger/inverter and the 400A main fuse. The unit fits nicely in there. Airflow is not ideal but when the built-in fan runs it does blow some air out of the existing holes in the bottom edge of that fiberglass curvy piece. A few weeks later I added a 12V fan on each side blowing out of those holes, which has substantially lowered the temperature in there.

I wired it with one of the shore power connections going directly to the charger/inverter. Then the inverter powers the entirety of Bus A. So when I disconnect shore power the 120V loads don't even know--it switches instantly to using battery power. With the PowerAssist feature it can even supply more than the 30A that would normally be available from shore power by adding in some power from the batteries too. I don't think we will ever have that much draw unless we are doing it intentionally (water heater plus electric kettle plus microwave would maybe be 4000 watts). The other shore power connection still goes to Bus B for the air conditioner.

I added an additional negative bus in the aft compartment under the couch. This is where the starting battery remains too. The old bus was a bit anemic for some of the larger wires I needed to connect to it. Later when I added the electric windlass I also added another positive bus bar under the nav station as I started to have too many things bolted directly onto the battery switch lug.

 

[aaronaxvig]

The Color Control GX provides a pretty graphic of where power is flowing between all of the components. It sucks in data from the MultiPlus, BMV, and solar charge controller. It logs to an SD card which I can take to a computer and upload to a Victron website (there are options for having the CCGX upload directly if you give it an internet connection). Then there are some pretty graphs generated on their website. I haven't checked that out much yet. Pretty good data is available using phone apps connected to either the BMV or solar charge controller via Bluetooth.

The BMV gauge fit perfectly in the old hole where the black water tank gauge was located. The CCGX I hacked into the hole left from the old Xantrex control panel. The Xantrex one was wider so I have a small gap on the less visible port side of the CCGX.

I haven't messed with what appears to be the alternator voltage regulator and a battery isolator. On one occasion I observed that the CCGX showed power flowing from the DC loads into the batteries so presumably that was the alternator charging the house bank. Probably the voltages of the LiFePo batteries are different enough that the battery isolator won't think that they need charging (big guess).