LiFePO Batteries ???

[alldodge]

That recharge volts is WAY too low for lithium. It needs to be closer to 13.4V

ll the info is very good, but how about a what if??

Bruce
What if you were doing this, what would you do/use

 

[bruceb58]

ll the info is very good, but how about a what if??

Bruce
What if you were doing this, what would you do/use

I would set to 13.4V That 12.5V setting is for lead acid batteries. If you left it at 12.5, the charging wouldn't restart until the lithium battery got down to 12.5V which is basically dead.

If it was my boat, I would have yanked that Xantrex inverter and put in a Victron. There is so much I would be doing different.

 

[tpenfield]

Yup, looks like 12.5v is the default and really meant for LA batteries . . .

Just referring to one our favorite charts, it looks like 13.0 volts might be a good number, which would put the SoC in the 30-40% range as a recharge point. I would think that values much higher than that would be charging the battery when it doesn't need to be charged.
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Guys, keep in mind that if this were your boat, you'd be getting ready to lift the boat off of the trailer and do bottom painting. Just saying . . .

 

[tpenfield]

A few final touches to the battery project. Boxes and covers in place. I relocated and re-purposed the battery labels.

The system has been working well. The EPEver does have a mind of its own and does whatever it thinks best.
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Still waiting for a string of sunny days to see how well the solar works. More clouds/rain than sun recently.

 

[alldodge]

Looks great, nice work as always
Bought a U1 size start Bat Lifepo for the lawn mower. They say just connect and go, hope it's that simple

 

[tpenfield]

Looks great, nice work as always
Bought a U1 size start Bat Lifepo for the lawn mower. They say just connect and go, hope it's that simple

Thank you .

It looks like 'starter' batteries are the next frontier for the LiFePO4 market. I am seeing CCA spec's in the 1000+ Amp range. However, it does not look like there has been much to address the issues of alternator (stator) charging. 'Smart' alternators are better suited. I'm thinking/hoping that if the BMS within the batteries can regulate charging currents a bit lower and have a slower shut-off/protection mode transition (instead of instantaneous), then they will be truly 'drop-in and go'. Not quite there yet, but for the most part it is working in many situations.

Larger capacity/CCA starter batteries are still a bit pricey at the moment . . . $600 and up.

 

[alldodge]

I got this one, will see how it works out,
https://www.amazon.com/gp/product/B091P9QXX7/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1

 

[tpenfield]

I decided to start the boat engines today. It turned out to be a bad idea . . .

With the engines running the DC-DC charger is powered from the alternator(s) and charging the LFP batteries, and the alternators are also charging the starter batteries.

On the PORT engine:
I was getting some fairly high voltage readings on the input to the DC-DC charger . . . 15-15.5 volts. However the VesselView was showing 14.0-14.2 volts.

The STARBOARD engine:
There was voltage fluctuations all over the place going from high (15.5-16.0) to low (10-11) . . . VesselView showed similar fluctuations. I finally got an over-voltage warning on the VesselView and I shut the engine down.

Fault code . . .
"4602/23"
" Fault Blocker System Voltage"
"A particular state or condition exists"

. . . it sure does

The engine would not crank at that point. After having a good lunch, I was able to get the engine started, and my volt meter is telling me the starboard battery is not charging.

Possibly, I have one of the wires to/from the 2 alt/3 battery isolator mixed up (unless I fried the alternator ). Got to check a few things . . .

 

[tpenfield]

Quick Update . . . after some poking around. I am focusing on the 2-alternator/3-battery isolator. I'm seeing voltage where I don't think I should be.

It is a good thing I put a bunch of CB's in the wiring layout. I can isolate things for testing and diagnostics.

 

[flashback]

This has been and still is an interesting thread. Turning a boats electrical system into a computer seems counter intuitive.i know you love the computer tech approach and I do wish it works out for you.

 

[tpenfield]

Thanks . . . it will become a more learning thread than it was.

Anyway . . . I figured something out that I had not really factored into the design. It seems that an alternator connected to an engine has some level of voltage on its output while it is NOT running. Pretty much around battery voltage, but there is very little current behind it. This voltage is enough to go through the 2 alt/3 batt isolator. I really had not designed the system with that consideration. So, I may need to change how I activate the DC-DC charger, as the voltage that it is seeing through the isolator is enough to activate it when it shouldn't.

Still thinking about it . . .

I'll be away from the boat for the next 2+ weeks, which is probably a good thing at this point.

 

[tpenfield]

BTW - I'm finding 1.0 - 1.5 voltage loss across some of the electrical junctions/bus bars, etc. . . . maybe 8 year old connections need some freshening up.

 

[tpenfield]

Here are my design modifications that I'll be trying when I am back at the boat . . .

A few minor changes to make the switch over from solar charging to the DC-DC charger based on the engine ignition being 'on' (engines running).

I'll also need to test the starboard alternator to see if it is actually working or has failed.

 

[cyclops222]

I have to admit that some boats have a TON of interconnected pieces of equipment.............With out experience in the different parts ? You can accidently cause more electrical problems. All my boats have USCG lighs and horn. Bilge pumps. VHF radio & antenna. Fish / depth finder. That is enough wiring to keep in good condition in fresh water.

 

[tpenfield]

Yup, this boat is the most complicated one I’ve owned. I think the newer ones are even worse.