Merged LiFeYPO4 1000Ah Winston prismatic cells and all electric galley...

[CatNewBee]

Originally Posted by alansmith

Catnew, thank u for taking all that time for posting up. How much money has been spent on this conversion? I am always amazed at how much things cost. Please share the actual costs involved. Because for most sailors we can only dream of what u r doing.

Second request, please include design costs and installation costs.

Oh well, the money...

5 x BenQ Panels each 306 € =1530 €
Victron SmartSolar MPPT 150/100-Tr =809€
stainless steel frame inclusive labour =2000€
flexible wires and cable shoes etc. =500€
breaker, diodes, electronics stuff, =100€
LFP cells LYP1000AHC 4x1240€ =4960 €
massive copper rail 2m =50€
4x latching relay 500A 12V ML-RBS =600 €
REC Active BMS mit Display, Kabel, Sensor=545 €
other material (stainless steel screws, washers, shrink tube etc. =150€
Victron Quattro 12/5000/220-100/100 =3082€
Victron BMV-712=214€
Victron MK3 USB Interface =71€

so inclusive the oven and the induction cooktop it was an investment of round about 16000€.

All parts were bought online; research, engineering and installation all DIY except for the stainless steel frame for the panels.

All prices incl. 19% VAT

Not includet is the price of the vessel of course [emoji56].

It was not that expensive, it's a lot of high-end electronics.

[rom]

Originally Posted by CatNewBee

The alternators will be disconnected from the house bank too, they will only charge the start batteries.

your following posts do not seem to reflect that. If you are setting up a system where you can connect/disconnect the alts to/from the house bank I'd be interested to know more.

[CatNewBee]

well, here the charger circuit details
fuses etc are not on the diagram, it is only a principal draft derived from the Lagoon docs...

[CatNewBee]

Originally Posted by rom

your following posts do not seem to reflect that. If you are setting up a system where you can connect/disconnect the alts to/from the house bank I'd be interested to know more.

disconnecting is easy so, because the alternators are connected to separation diodes and then one side to the start battery and the other to the house battery.

If you intercept the wire to the house, the alterator still runs under load on the start battery via the 2nd path of the separator diodes block, it is safe to disconnect the house bank.

[AZ-Oldguy]

I am very interested in this topic, and very frustrated because as someone who is fairly new to the subject of marine electronics and charging of batteries I do not know what all of the many different acronyms mean. I can read but I get no picture of what is being used or what is going on. What is REC ABMS ? For example I haven't a clue. Nor do I have any idea where I could go find out what that meant so that I could begin to make sense of or harvest some useful information out of this post just once in awhile if people could take the time to actually say the full word, followed in parentheses by the acronym for abbreviated version then I could begin to make sense of the article. End of rant. Glenn

[CatNewBee]

Originally Posted by AZ-Oldguy

I am very interested in this topic, and very frustrated because as someone who is fairly new to the subject of marine electronics and charging of batteries I do not know what all of the many different acronyms mean. I can read but I get no picture of what is being used or what is going on. What is REC ABMS ? For example I haven't a clue. Nor do I have any idea where I could go find out what that meant so that I could begin to make sense of or harvest some useful information out of this post just once in awhile if people could take the time to actually say the full word, followed in parentheses by the acronym for abbreviated version then I could begin to make sense of the article. End of rant. Glenn

Hey Glen, no problem.

I am talking about lithium iron phosphate cells with yttrium dotation, or LiFeYPO4.

Lithium celss have a very high energy density, but also need some good electronics around, that monitors the cell health (voltage) to keep them in a safe range, otherwise they can be destroyed or even worse have a thermal run-off.

This circuit is called BMS or battery management system. The REC ABMS is a product of a slovenian start up company called R.E.C. and the ABMS means active battery management system.

This referes to how the cells are monitored and balanced. An active BMS takes charge from one cell, uses a step-up converter and charges the bank with that energy, if one cell has higher voltage than the others - or uses the battery voltage by a step down conversion to charge a single cell, that has lower voltage than the others, so very little energy is lost by the balancing.

in contrast a passive BMS just uses resistors and burns the excess energy of the cells with a higher voltage.

It is completely different to lead acid batteries like wet, AGM or GEL batteries. There are some threads that explain pretty well the differences and requirements.
Flooded batteries are equalized by so called reconditioning, they are charged with over-voltage of 15V and more to get controlled gasing until all cells are equally overcharged. Sealed batteries like AGM ang GEL will not survive reconditioning, they will blow off and get damaged.

I am just sharing my solution, and a forum is a good thing, you always can ask if you do not understand something.

btw, there is a web site called google.com, they answer almost all questions. If you ask them about REC ABMS, they will bring you straight to this home page

http://www.rec-bms.com/ABMS.html

[alansmith]

Catnew, thank u for showing the costs of a first class install. May I ask what is your background with electricity? Your install is pretty sophisticated.

I have a 30' trimaran that I am seriously considering to go solar/ lithium. I think I can do just fine with about 400 amp/hr. I will probably just use a 2000 watt gas inverter for those one week nasty weather windows. My wife and I think that having a smallish water maker aboard would be an nice feature.

What is your thinking about how much battery bank you need to run your water maker without starting up some sort of generator assist? Do you need a soft start feature so the water maker doesn't stress out the battery? Teach me because I have slot to learn. Much appreciated

[CatNewBee]

Well, I have an university degree in electrotechnics and computer science, but my career was in the IT. Nothing marine related, Volt, Amp and Watt work the same on land and on the water so...

Regarding your project. The batteries will be not the problem, but probably the inverter.

LFP cells Winston LiFeYPO4) can be continously discharged with 1C, for 15 minutes even with 3C and foc some seconds with 10C, that means for a 400Ah battery, you can draw 400A without a problem for 1 hour or even 1200A for 15 minutes or 4000A for some seconds.

That is serious stuff. 400A at 12V are round about 4kW, far more than your inverter or watermaker needs. With a 12V watermaker no problem at all, a 220V or 110V watermaker requires an inverter that is capable to provide enough energy when the motor starts, it is often 3 times the power usually the motor consumes because of the mechanical resistance and the magnetic field etc. So to not oversize the inverter there are soft start devices that increase slowly the current and protect the inverter output.

it depends on your choices for the watermaker what circuitry you might need. 400Ah 12V LFP gives you round about 4kWh of usable energy, should be enough for the watermaker, but you need to estimate all your power requirements and add some capacity for safety.

[alansmith]

CatNew, thanks mate! Much appreciated. Where are you currently berthed? Once again, thanks for your excellent write up. There is another thread of similar design and installation currently going on with sailadastra.com. Have you read his installation?

I am so amazed at you guys. It is the way i wish to go also.

Are you using lead batteries for your twin diesel starts...or going with your gynormous Lithium battery capacity to start the engines? With so much capacity is it really worth carrying the lead around? If carrying lead around how many amp/hr battery/batteries are you dedicating for each engine?

I have a 10 hp Tohatsu outboard with electric/manual pull start. I am assuming that when i get down to designing the schematics i will have the engine wiring led to the Victron (or who knows). I am also thinking that i should have an inverter generator also on board JIC cloudy rainy weather creams the photon bombardment of the panels.

How much fudge factor are you calculating for inclement weather? What i mean is how much extra capacity are you calculating in for weather? How many days of normal usage of battery bank before you have to use dino juice?

The fella who is doing the Ad Astra install stated, if i understood the writing correctly, that he won't worry about low level warning circuitry ....The electronics to monitor this situation used up way too much electricity.

Could you explain more simply how you will be able to jump between solar panel juice, over to generator juice, versus shore power. I haven't been able to figure out how the BMS handles that switching without manual manipulation of switches.

Respectfully, alan

[AZ-Oldguy]

Thanks Catnewbee, that was really helpful.*

Glenn

[CatNewBee]

Hi Allan, lots of questions...

I am in the Med in France currently.

We purchased a pre-owned cat, so I use what I've got.
There are spiral cells AGM starter batteries on board, that are almost new, so no need to change.

The house bank was 4x120Ah Excide equipment gel batteries in parallel configuration, one run uff while charging (cell shortcut) and boiled and smelled awfully, a second one has a damaged cell (high resistance, low voltage), 2 left somehow with 80..85% SOH.

Lagoon considers the 4 batteries as an upgrade to the standard 2 batteries set-up.

There was also a generator start battery sealed lead acid, that was dead too.

I will keep the spiral cell AGM start batteries using the the factory installed charging circuitry unchanged. Reason is - no additional costs and effort and redundancy if one cell of the house battery fails. Then I can easyly hook up one of the start batteries to limp home with working navigation, lights, vhf etc. without running the generator or an engine all the time.

however I got rid of the generator sarter battery, 2 AGM as spare are enough, I would have kept her as long as she was ok, but there was no reason to replace her.

The next question is not easy to answer, because we bought the vessel in december last year, not much experience on the energy consumption on the way for the base line. However, I have done some calculations and educated guesses when sizing.

First, I assumed Lagoon knows what they are doing with electricity and 240Ah GEL basic means 120Ah usable capacity should be enough for navigation during the night.
480Ah (extended battery) translates to 240 Ah usable capacity. Well this was way too optimistic I found. I chose 4 times more usable capacity with lithium, got the biggest available cells that can be squeezed in, you never can have enough. I do not like parallel/serial cell installations, this set up adds complexity and trouble that you need to mitigate if one cell fails. Same for solar. I chose the bigest high voltage cell I could get that is rigid and tested in salty environment and calculated how many of them I can potentially fit, then looked for a controller, that is programmable and can handle the power. The array has 5 330Wp panels 1650Wp in total, that yelds in average 6400Wh / day (easy estimation for solar installs is Wp x 4). This translates to average 470Ah of energy that you can expect to harvest in average (6400Wh / 14V) Average means sonny days, clody days, distributed over the seasons. So in the summer with long daylight and sunny weather you may collect 700Ah, and during the winter only 50Ah.

The good thing with Lithium is, they have a very low impedance (resistance) compared to lead acid, that means, they have very stable voltage on charging and discharging what leads to high currents. So they can swallow any amp they get and are very efficient with solar.

Being on board I just turned on all fridges / freezer (there are 3 of them) to coldest setting, also lights usage in the evening and measured the current / power consumption over 3 days and got the average power consumption of the house (350-400Ah / day). This is what I would need at least on anchor. That was good news, my solar is able to keep me living off the hook in average without the need of a generator.

Now testing the setup. Yesterday it was very cloudy and rainy, the day ended with - 100Ah, (90%SOC), today in the morning there was -310Ah running all systems living on board, including 10 minutes usage of the oven and 15 minutes cooking on one Induction field. That said, I could probably survive a cloudy week off the hook. Today it is sunny, will see when the battery is full again and compensates the loss of yesterday plus the running consumption of today.

The consumption of navionics, radar, autopilot etc. can easyly be measured by turning them on and looking at the current gauge. However as liveaboard you are most of the time at anchor, so sailing will be covered somehow but is not the main use case for the calculations.

My goal was to survive 3 days without additional energy at cloudy conditions. I guess, goal achieved.

On sunny days, there will be enough energy for the watermaker, boiler and eventually for one A/C.

When the weather is nice, the battery is full at 1pm, compensating the night and the the consumption of the morning, so the rest of the day you have excess energy for whatever you choose.

[hzcruiser]

That's a boat load of good information you put out there, thanks for that!


All meticulously documented, just what you expect from an engineer


And you even take the time to answer the questions people have about your (and their) setup, next to finishing your own boat and getting ready to cruise? Wow.



Good on you!

[CatNewBee]

Regarding jumping between the charge sources and the role of the BMS.

Electricity behaves exactly like water, that is the reason we call it current.
The Voltage is like the hight difference between a mountain where the source is and sea level where the drain is. Current flows from high to low, if there are more sources, they join in the stream and add to the current.

This is what happens when you connect multiple charge sources in parallel. the one with the highest Voltage difference will add the most current , the others will contribute their share. If one of the sources has a lower or equal Voltage than the battery (the drain), there will be no current from this source. Current will not flow usually in reverse into a source, because thise sources are made with semiconductors / diodes, that block reverse currents / wrong polarity. There is no need to switch between the sources at all. If you want to control what source charges, turn the others off.

The BMS is a different beast. His main task is to protect the battery. There are very different more or less sophisticated solutions called BMS. In the LFP world a must-have is cell monitoring. So almost all BMS measure the cell voltage and react on it. They produce one or two signals on programmed or hard wired thresolds : STOP CHARGE or OVP(over voltage protection) and STOP DISCHARGE - or UVP (under voltage protection), simple bms just disconnet the battery if one of this signals occure.

The second task is to balance the cells - to keep them at the same voltage, especially on the high side when charging and/or on the low side when discharging. A LFP cell has, as said before a very low resistance (some milli-ohm) in normal operation, so the voltage is almost constant in a wide range of SOC. This changes drammatically when the cell is full or empty. So while charging not equalized cells, o e is faster full than the others and quickly runns off, so can be damaged or overheat. Balancer in the better BMS take care of this. Simpler just selectively discharge the higher cells until they meet their neighbors while charging, usually this starts above a programmed Voltage threshold, so the balancer are inactive in normal operation. Simpler BMS do not care about unequal cells on discharge, they just fire up UVP signal when the first cell hits the bottom.

Better BMS leverage the full potential of the battery by actively monitoring the cells and redistribution of the charge. On the upper end they not burn excess energy, but recuperate it to the other cells, on the lower end they use the remaining battery energy to charge the lowest cell and help to use the maximum available capacity, in regular operation they measure the cell resistance and voltage difference to estimate the cell health and if the difference becomes too big, they equalise even then the cells if necessary.

A good BMS also monitors the cell temperature and disconnects charger or loads or both if necessary. LiFePO4 should not be charged in sub zero conditions, while LiFeYPO4 can be charged (with reduced current) down to -40 C.

A good BMS has also a connection to the shunt and is aware of the current currents in and out and of the SOC / SOH of the battery, a even better BMS is fully programmable with all relevant parameters to various use cases and chemistries.

But bottom line is, it is a smart fuse, that protects the battery cells and keeps them equaly charged. So from outside it is like any other battery and can be dropped in.

With the right environment like the Victron quattro, and some custom programming you can use the BMS to do even more to early reduce voltage / current or turn off the inverter BEFORE the BMS must fire up OVP or UVP as last resort of protection and everything runs smooth.

Permanently connected charging sources should be programmed below the thresholds of OVP, that means they shut off themselves long before the BMS must protect the battery, same for high-load consumer like inverter (shut off on low voltage), so the battery remains all the time online without interruption.

I have separated the legacy charge sources and control them on top of the BMS based on SOC, the advantage is, I use them only when necessary and only to bulk load the house bank, they remain programmed to AGM profiles and are optimal set up for the AGM start batteries, most of the time they will never see the house battery at all.

The system is then optimal for both chemistries and the altrnators are not stressed by the high amps of the house battery at all.

[CatNewBee]

Originally Posted by hzcruiser

That's a boat load of good information you put out there, thanks for that!


All meticulously documented, just what you expect from an engineer


And you even take the time to answer the questions people have about your (and their) setup, next to finishing your own boat and getting ready to cruise? Wow.



Good on you!

Thanks.

Well talking about the project has some benefits, it is a review of what you have done when discussing it with others, and sometimes you even learn from other solutions or think about side effects by the upcomming questions, so you can improve your system. Its a win-win...

[rom]

Originally Posted by CatNewBee

disconnecting is easy so, because the alternators are connected to separation diodes and then one side to the start battery and the other to the house battery.

If you intercept the wire to the house, the alterator still runs under load on the start battery via the 2nd path of the separator diodes block, it is safe to disconnect the house bank.

Yes indeed, that's how it works on my L440 too. Alternators disconnected from the house about 330 days a year. But I want to get rid of those heavy useless starter batteries and have a single emergency battery instead. I will be in Hyères a lot this summer, if you are nearby I'd be happy to meet you, I have done quite a few modifications myself.