LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

[roetter]

I am including an updated picture of your battery switches.

Attachment 85671

Please use caution. I am doing these descriptions from my memory of doing work on three L450s, converting two of them to LiFePo. Verify that my annotaions are correct. Make your ouwn notes. Lable each cable. If nothing else use white electricians tape and a permanent marker to lable the cables.

As you can see, you got a few things right and some wrong. Interestingly they switched the order of the switched, unless your camera made mirrored images. Number 130-280 had the swicthes the other way around, at least.

The switch with all the black cables is the negative for house and starter bank. The thick black cable is probably the negative from the Victron that Robin Marine installed.

House Positive switch
The switch on the right with mostly read cables is the house positive switch.
These are the cable going to and coming from it:

Postive from battery - coming into the picture from the top left to the upper stud.
Alternators port and starboard - coming as a double cable from the right out of a black flexible tubing. Also connected to the upper stud. This way the alternators can never be disconnected from the battery. I do not tecommend that. Place them just like the solar onto the "charge" bus bar. The starter batteries are always connected to the alternators, so disconnecting them with the solenoids while running does not blow their diodes. At least mine are doing fine after being disconnected many times while the engine was running.
12V panel - red cable from the lower stud going up then turning down into a shunt (black box) from there it goes to the main 12V switch panel. Only the Amps going through this panel are shown on the LCD display on the 12V panel. That would be lights, fridges, navigation instruments, water pump. All the things you have switches for on the panel.
Windlass - From lower stud to the breaker on the far right.
Winch breakers - Thick red cable dissapearing to the right of the picture. The breakers for the winches are in the cabinet next to the door when you come into the aft cabin.
Assume Victron +(pos) - The black cable with the red shrink tubing on the end. It is attached to the upper stud. This means that you can not disconnect the Victron from the battery using the switch. Bad Robin Marine.

Assume Victron - (neg)- Thick black cable coming from the right into the picture going to the upper stud of the house and starter negative switch. Again it is connected on the nattery side of the switch, which is bad. No way to disconnect it from the battery with the switch.

Robin Marine is likely not interested to do real good job, and it would be expensive too as many hours will be sunk into it. Best may be to do most of the work yourself and have Robin check it over. I am pretty sure they would agree to that.

I would:
install
- a Load bus bar - connect cables winch, windlass, victron, 12V panel
- a charge bus bar - connect alternators, solar

Both bus bars are connected via solenoids (the larger one on the load) to the battery switch lower stud. Use a very thick cable for the load bus bar. Thicker than what Robin Marine used fo rthe Victron or double u the cables. Don't skimp on this!

Eric Marine will let you use their tool to crimp your own 12V thick cables. Better yet buy your own battery crimper if you can find one easily. Sooner or later you will have a bad cable that you need to redo.

You can find all you need to know about battery cables on Maine Sail's site here:
Making Your Own Battery Cables Photo Gallery by Compass Marine How To at pbase.com

Also, get a heat gun as shown in the link below - also from Main Sail. I use it regularily on my cables. Found two bad connections recently on my solar side. Only works if there is a lot of current running through the cables.

Engine Temp Monitoring & Over Heating Baseline Assessment Photo Gallery by Compass Marine How To at pbase.com

[markv]

This is most helpful, thanks Rolf. I expect others will find it just as useful and I will post more info as we progress. We are on the pontoon between Eric Marine and Robin Marine so it's quick to get to either one...and we are good here for another week according to the Dockmaster..

i took the pics with my mac laptop, so the images might be reversed...but the order of switches is slightly different to the manual anyway.

As we researched more and examined what was there, it became apparent that we definitely need those busbars and also some labeling, so will buy some tomorrow first thing. Hoping I can get ones with enough connections, or will have to buy 2 each for load and charge. When we are done, I want to be able to look at it and see what each cable does. I wonder why Lagoon don't do that in the first place. The other smaller busbars on the other panels are well organised...maybe they figure people will change it anyway...:-)

As for your corrected picture...yes, I think all is correct there. I wrote winch..I meant windlass..lol..we know about the winch breakers in the cupboard. I sent the picture to Peter at Calb Europe and he did mention that it was a bit messy, and the electrician should kill the snakes..

We are becoming more comfortable with the layout, and I guess will get into it properly tomorrow. I think Robin Marine will be curious and want to get involved with the LiOn system - I think there are more and more clients who want the same stuff.

I will add the 2 x Flex Max 80 MPPTs and the hub in the same area as the Victron and lead wires to a junction box/switch above the engine ...this will be ready for us to install the 6 Benq 325W solar panels once the array is completed, at least all the wiring will have been set up. The mate 3 and Ligoo displays will go on the same area as the VE.net and mastervolt displays

Will update again tomorrow..:-)

[hellosailor]

markv-
If you are going to DIY and you are not electrically experienced, forgive me if I caution you to remove ALL JEWELRY INCLUDING RINGS AND WATCHES before you start. Working on batteries exposed you to extremely high amperages that can cause traumatic amputations from these things. And a slip of a wrench can be just as deadly, even explosively so.
So you might also want to take some heat-shrink tubing, or electrical tape, and insulate the handles of any tools or wrenches that you are using on the battery cabling.
Battery wiring is not dangerous IF you remember to ensure that short circuits are going to be physically impossible. Similarly, if you attach one end of a cable? Make sure the other end is inside a plastic pop bottle, or similarly unable to close a circuit to anything else.

It isn't rocket science but "measure twice cut once" is a good concept. When you're ready to hook up the last bit and go live...don't. Go take a break, have a cold drink, come back and look it over again before you hook up the last bit.

Sometimes "boring" results are a very good thing. And easily done, even by a first-timer. Measure twice, cut once.

[markv]

Hellosailor - thanks for the advice.., will heed it - I had a Lagoon 440 for 7 years, so we have worked on electrics somewhat - always good to be reminded tho. We are careful, as I have had the odd shock before but this time we are working with 1600Ah LiOn, a lot more power than we had before... Just need to get a handle where all the cabling goes at the moment and re organise it and label it first...garanteed in a few months I will forget what goes where..:-)

[deckofficer]

Originally Posted by hellosailor

markv-
If you are going to DIY and you are not electrically experienced, forgive me if I caution you to remove ALL JEWELRY INCLUDING RINGS AND WATCHES before you start. Working on batteries exposed you to extremely high amperages that can cause traumatic amputations from these things. And a slip of a wrench can be just as deadly, even explosively so.
So you might also want to take some heat-shrink tubing, or electrical tape, and insulate the handles of any tools or wrenches that you are using on the battery cabling.
Battery wiring is not dangerous IF you remember to ensure that short circuits are going to be physically impossible. Similarly, if you attach one end of a cable? Make sure the other end is inside a plastic pop bottle, or similarly unable to close a circuit to anything else.

It isn't rocket science but "measure twice cut once" is a good concept. When you're ready to hook up the last bit and go live...don't. Go take a break, have a cold drink, come back and look it over again before you hook up the last bit.

Sometimes "boring" results are a very good thing. And easily done, even by a first-timer. Measure twice, cut once.

Very good to mention.

If you thought your lead acid banks could be destructive during a short (wrench, rings, jewelry), you ain't seen nothing compared to the amps available form your new LiFePO4 bank.l

So by all means, be very careful.

[hellosailor]

Yes, one "car" sized conventional deep cycle battery can put out over 3000A into a crowbar short. I got complacent and welded the bezel on my watch one day, I now make sure to pocket the watch as well.

On the cable labels, some of the other forum members mentioned the Brother P-Touch in the past. I've had similar gizmos (Esselte/Dymo) produce labels that literally turn black in the heat, but the Brother apparently is different material, and they make specific cartridges for wire labels, extra durable, extra flexible, extra heat resistant. If you can get that there, a bit pricey but a very nice long term solution.

If you need something temporary, Tyvek (the plastic paper used for many shipping envelopes and house-wrap) and a permanent marker, wrapped with genuine Scotch Magic tape, lasts a very long time. Or the Tyvek, backed with a heat-resistant adhesive, or "tied" as a tag.

As an honorary Scotsman, I'll say the Brother P-Touch is worth whatever it costs you.

[botanybay]

Originally Posted by hellosailor

markv-
If you are going to DIY and you are not electrically experienced, forgive me if I caution you to remove ALL JEWELRY INCLUDING RINGS AND WATCHES before you start. Working on batteries exposed you to extremely high amperages that can cause traumatic amputations from these things. And a slip of a wrench can be just as deadly, even explosively so.
So you might also want to take some heat-shrink tubing, or electrical tape, and insulate the handles of any tools or wrenches that you are using on the battery cabling.
Battery wiring is not dangerous IF you remember to ensure that short circuits are going to be physically impossible. Similarly, if you attach one end of a cable? Make sure the other end is inside a plastic pop bottle, or similarly unable to close a circuit to anything else.

It isn't rocket science but "measure twice cut once" is a good concept. When you're ready to hook up the last bit and go live...don't. Go take a break, have a cold drink, come back and look it over again before you hook up the last bit.

Sometimes "boring" results are a very good thing. And easily done, even by a first-timer. Measure twice, cut once.

Very good advice. Just like when working on high voltage one always keeps one hand behind their back!

I am the paranoid type, I always remove the primary battery banks fuses prior to working on the main DC bus. (i.e. the ones down in the battery box in my case).

[campr]

To the great amusement of my buddies, I was troubleshooting an ignition problem in my car leaning on the wing with one hand. Lesson learned!

[markv]

Had 2 guys come in from Robin Marine to talk it over, and we will do it in 2 steps. Re organise the battery cabling to use the bus bars for load and charge which they will start tomorrow, while we mount the flex max MPPTs and BCU and BMU in readiness. Then when they have redone the wiring and connected back to the system to make sure it all works, the next day we can take out the 6 x 140Ah LA batteries and drop in the Lithium Ion bank, then connect the cabling to the BMS and equalizer. Made sure they understood the increase in size going from the bus to the contactor and battery, and they were talking about 125mm cabling...that's massive.. - Anyway, rather than doing it myself, will let them do the cabling and take any risks, apparently it will only take a day..

I plan to run 2m of neg/pos cabling from each flex max 80 unit to a junction/switch above the engine compartment - I think that 2m x 25mm cabling should be ok for that, and then 6mm cabling from the junction box to each 325W solar panel, connected in parallel, then repeat the setup for the other 3 panels. Lengths will for them will be about 5m for one set of panels and maybe 7m for the other set.

BTW, I asked Robin Marine why they connected the Victron to the upper stud, directly to the battery and they said it is because you can cut the load to the battery, but you might still want to charge it.

[Maine Sail]

Originally Posted by markv

BTW, I asked Robin Marine why they connected the Victron to the upper stud, directly to the battery and they said it is because you can cut the load to the battery, but you might still want to charge it.

Just be sure the Victron is controlled by a HVC cut in-case it goes haywire... A charge and loads bus is just a smart installation with LFP... Are you using any cell compression or case? Those straight pieces of copper could really work the terminals if the cells are not held in place rigidly..

[markv]

I have 2 Valeo alternators, 125A each - does anyone know if I can adjust the max power output to 13.8V? They will be charging both the LiOn bank and the starter batteries, I am just thinking maybe I need a voltage regulator?..They will attach directly to the charge busbar and there will be a solenoid relay between the battery switch and the busbar...

MaineSail - The Ligoo BMS will connect to the Victron (although still working out how to connect it), and either one can control both Solenoid contactors between Load and Charge busbars. There is no case, as no room for it, but I will strap them together using the same strap that came with the boxes when they were delivered.

[Maine Sail]

Originally Posted by markv

I have 2 Valeo alternators, 125A each - does anyone know if I can adjust the max power output to 13.8V? They will be charging both the LiOn bank and the starter batteries, I am just thinking maybe I need a voltage regulator?..They will attach directly to the charge busbar and there will be a solenoid relay between the battery switch and the busbar...

MaineSail - The Ligoo BMS will connect to the Victron (although still working out how to connect it), and either one can control both Solenoid contactors between Load and Charge busbars. There is no case, as no room for it, but I will strap them together using the same strap that came with the boxes when they were delivered.

Mark,

Please do yourself a favor and convert those alts to external and use a Balmar MC-614 regulator or better yet get alternators that are designed to handle this type of abuse.

Your alts are most likely internally temp compensated and your LFP bank will drive the voltage down to try and save the alt from cooking itself, not a good set up for LFP.. LFP should really be designed as a "system".....

[markv]

If we need to replace the alternators we can do that later, as I am not sure we can get Balmars here in Les Sables in time, for now I will need to get voltage regulators on them so the voltage hitting the charge bar is 13.8... I tested the voltage coming out of them just now and it's 14.3v.
I was going on the advice of Rolf, who has Mitsubishi alternators, which is what I thought was going to be on when we bought the boat, but Lagoon seems to have changed to Valeo...

If I can get what I need from Defender, we can order it for arrival in Gibraltar when we get there in a couple of weeks..we are ordering some other stuff, so that would work out. What alternators would you recommend to buy exactly?

[markv]

We spent today re arranging the cables and mounting the BMS, Flex Max and relays. I have enclosed some pictures. There are 3 busbars now, one for charge, one for load and one for Neg. At the moment, the batteries go directly to the busbars and no switches - tomorrow morning we will be connecting battery to top stud, adding 120mm2 cable between bottom stud and contactor and from contactor to busbar.

I am not sure how to connect the relay to the Victron, so that we can open it when charge is 100% full, and close between at 80% - we don't yet have the victron battery monitor - does it connect to the Victron Quattro unit or the battery monitor?...there is a programmable relay for generator start from the Victron Quattro, so maybe that is the connection?..and then program it from the battery monitor...

We can then drop then batteries and and connect up 5 connections from the BMS to measure and monitor each pack, and also the 5 connections from the equalizer that will actively balance each set of 4 batteries.

We have installed the Flex Max Units, and run the wires out to the back in the engine compartment, and also connected them to the charge bar - now looking for 2 x 80A breaker switches in a junction box to connect the 6mm cables from the 6 solar panels

Getting there slowly..

[botanybay]

Originally Posted by markv

We spent today re arranging the cables and mounting the BMS, Flex Max and relays. I have enclosed some pictures. There are 3 busbars now, one for charge, one for load and one for Neg. At the moment, the batteries go directly to the busbars and no switches - tomorrow morning we will be connecting battery to top stud, adding 120mm2 cable between bottom stud and contactor and from contactor to busbar.

I am not sure how to connect the relay to the Victron, so that we can open it when charge is 100% full, and close between at 80% - we don't yet have the victron battery monitor - does it connect to the Victron Quattro unit or the battery monitor?...there is a programmable relay for generator start from the Victron Quattro, so maybe that is the connection?..and then program it from the battery monitor...

We can then drop then batteries and and connect up 5 connections from the BMS to measure and monitor each pack, and also the 5 connections from the equalizer that will actively balance each set of 4 batteries.

We have installed the Flex Max Units, and run the wires out to the back in the engine compartment, and also connected them to the charge bar - now looking for 2 x 80A breaker switches in a junction box to connect the 6mm cables from the 6 solar panels

Getting there slowly..

On the Multi an Quattro there is an "assistant" which turns on of the dry contacts into a feature which disables the charger when activate and another which disables the inverter when the bank is too low.

I think there is a significant discussion on Victron's website which discusses using an non-victron BMS with the Quattro, I saw this mentioned on the Victron Blog.

I believe that this repurposes the generator start relays.