Lucia 40: DIY Lithium Bank Install

[MKB53]

I am using a REC BMS. Made in Slovenia and they have a couple of different models. Mine manages 4 cells maximum but they have a model that caters for more.
This is my 2nd one and they have performed well, the one on my old boat has now been in service since 2011.

With regard to current draw on the relay - Your BMS will probably draw current as well and more than the 8Ma. This is fine if you are leaving your solar on but if you want to disconnect completely you will need to isolate that as well.
In theory the draw down would be well within capacity but I prefer to err on the safe side.

[travellerw]

Yes.. Our system is designed for complete isolation of the batteries in the event of storing. No draw at all (not even ma). A spiral AGM becomes the standby battery to run the bilge pumps while the LiFePo4 bank sits completely isolated.

In the even we go to a dock. Then the batteries will be isolated using the lock off switch. The boat will be powered by the Quick battery charger. Its rated to be used as a power supply with no battery connected. However the same AGM can be wired in to provide some backup/redundancy.

[Terbonium]

Originally Posted by MKB53

I am using a REC BMS. Made in Slovenia and they have a couple of different models. Mine manages 4 cells maximum but they

My REC just arrived yesterday and will be replacing my temporary BMS with it shortly.

Are you using a Victron charger? Is it connected to the BMS via CAN?

[LilleVenn]

Terbonium, this, together with your solar system is the nicecst installation I have seen. We'll get our Helia in july and I would like to do a very similar setup like yours. I have studied all your posts in the forum and know the information from it (3 * X22, individual Victron 100/30, CALB 180AH). Would you be so nice to share more details of your planning and installation to make it easier for me?
In any case, thank you for all the great information you have already shared with us.

[Helia 44]

Helia 44 here, now a Saba 50 from Australia.

I am somewhat of an honest EXPERT at this, and not biased by trying to sell you something. In my Business (and no I am not selling anything here) my Business is outfitting Bushtracker Caravans (4x4 off-road travel trailers in your language) for independent living in the Outback.. 22 years ago, when I started, I called them "Land Yachts" for the Outback... Trust what I have to say, this is neutral help for you with no bias for $$.

Anyway, that is how I have an extreme amount of experience with Lithium installations. My own is 600 AH in my Bushtracker. I would have the experience of about 200 installations, for about 7-8 years now. I have some comments to help you along OK? I am the Professional, but not selling to you, this is just a help for you 'f.o.c'.... Not bent by economic bias..

FIRST: Now the key to longevity of your Lithiums, is proper equipment to manage them. You need a quality B.M.S. (Battery Management System) that monitors and equalizes all the individual cells. Secondly, if you are using say two 200 AH systems in parallel or two 300 AH systems to make up your total AH, it could even be 3- 300 AH systems, anyway you need another type of overall BMS that "Equalizes" all of them together.. So, two BMS systems, one for each battery set of cells in series to get the individual battery to the right voltage, and one for them all hooked together in parallel to get the total AH you desire.

Next you need a monitoring meter, like the Enerdrive one or the Victron one, that runs something like the Blue Sea Relay Driver to run an LVD (low voltage disconnect). This meter runs the LVD, it also tells you total AH in and out and your charging in bar graphs and so on. This is your insurance. A latching relay LVD disconnect, run by a Relay Driver, triggered by your monitor Victron style. You can also have an LVD backup that triggers the Relay Driver. We have had a near nil failure rate in this gear of relay drivers and latching relays. For long term storage, you also would need to disconnect the entire battery system from the BMS, as it is a long term steady drain of about 3/4 amp/hr. Store them fully charged and you are good for about six months to a year depending on the size of the system.

And also sometimes not talked about: You also need DC to DC chargers, on the output of you battery charger and your alternators. (Unless your battery charger is newer and has the Lithium algorithm built into it). These DC to DC chargers have to be Lithium programmed to put the charge in properly in the Lithium algorithm. Most will tell you that you do not need them, to keep the costs down, and this is not true.. The same goes for your battery charger, it must be programmable for the Lithium algorithm or have a DC to DC charger added in after it. The DC to DC chargers with the LIthium algorithm have to be triggered by your ignition or alternator firing up, or they will continue to flatten your starting battery.. Failure to do this and you can potentially wreck your investment and shorten the Lithium Battery Life down to as much as five years, when it could be twenty. But the Company that told you- you do not need it, will not likely be around by then. Do not let someone tell you the standard charging curve will do, yes it will work, but our long term experience show that it will also shorten the life of the batteries themselves.

Now my summation comment is not necessarily trendy but in your best interests: In my extensive experience with 200 systems running independently, I have one more idea you need to soak in. It is hard to justify the costs, when it costs about as much to do it correctly as buying 3-4 sets of batteries. Yes it charges faster, yes you can pull more out of it, yes it is nearly a zero resistance system, yes it takes more solar, but after saying all of that the biggest advantage is weight savings. My Saba 50 is running on 7 Varta Euro 123 or 150 AH batteries. Wow, that is like what, over 500 lbs? Anyway if you are weight sensitive then the Lithium makes sense. I am not, so may not bother. Diesel is cheap, and I have a low hours 11 kva Cummins Onan with a Kubota tractor engine driving it, probably a 10,000 hour unit and it has about 250 hours on it, with two Victron charger/inverter systems. I also will not even consider the change over until my existing batteries are sick. Honestly, if you are not weight sensitive, there are some functional advantages to Lithium but you have to have a perfect system that lasts as long as 3 or 4 sets of regular batteries= About 20 years. Don't get caught up in the Lithium trendiness, as it is hard to justify when you take out the weight advantage, unless you are a Minimalist trying to be Green and run all on solar and wind generator.. That is not me, I have a medical condition. In the heat of the GBR (Great Barrier Reef area) I have six CruiserAire air conditioning systems and a 180 litre/ hour water maker on a luxury yacht, and diesel is cheap. I may go to Lithium for green reasons, but I have a health condition that may make me stay with the air conditioning and abundant water supply. I can run one air conditioning unit in moderate conditions overnight on my 600 AH system. With enough solar I might make it work, but really could use a huge investment with two 600 AH Lithium banks to do it all right...

I hope I have been a help. This is what you need to make it cost effective and long enough lasting to pay off, over regular batteries. Probably advantaged more in smaller yachts that are weight sensitive to get the full pay back on your investment.

Kind regards, "Helia 44" now on a Saba 50 "Serenity" in Australia, cruising the hundreds of Continental Islands inside the Great Barrier Reef.

[Terbonium]

Originally Posted by LilleVenn

Terbonium, this, together with your solar system is the nicecst installation I have seen. We'll get our Helia in july and I would like to do a very similar setup like yours. I have studied all your posts in the forum and know the information from it (3 * X22, individual Victron 100/30, CALB 180AH). Would you be so nice to share more details of your planning and installation to make it easier for me?
In any case, thank you for all the great information you have already shared with us.

Thanks, I'm happy to help and share what I've learned thru the process.

Battery Choice - Cost and cell manufacturer reputation were the two primary concerns here. There are various lithium chemistries available, but not to get into all those details I chose LiFePO4 for safety and simplicity (this eliminated buying most cells from used electrical vehicles)

The easiest savings for lithium is to build your own pack vs prebuilt systems. Currently the cost of very complete ready to run systems is about $10/AHr. Building my own pack reduced this to $5/AHr. Building my own system was simplified by the fact that my existing charger/inverter is a Victron which support custom charge profiles to charge lithium cells.

I ended up purchasing 16x CALB 180FI cells from their California warehouse to help guarantee their quality. I could have saved a few $$ ordering from China directly, but I felt like there was too much left to chance and getting knock off or faulty cells worried me too much.

Charging and BMS - My existing Victron equipment supports custom charge profiles so that part is pretty easy. I chose the REC-BMS to monitor the cell voltages because it can talk to the Victron inverter/charger over the network to adjust charge current and if needed shut down charging/discharging. In addition I have a Victron battery protect which can be triggered by the BMS directly to disconnect the pack from the system.(note that I have the battery protect configured independently to disconnect if pack voltage goes below 12v OR above 16 OR on signal from the BMS, this way if for some reason the BMS fails, the battery protect can still make its own choice to shut down).


Solar - As much as you can fit on the boat. Looking for oddly shaped panels that would fit the coach roof is what led me to find the SunPower X22 panels. The fact that they were among the most efficient panels on the market, approved for marine install and sold just down the street from me in Florida was all a big bonus! I'm very happy with the way they were installed. Hardly visible when viewing the boat from the water. They don't interfere with sailing or any boat operations. I know we could have added more with some overhang off the back, but not wanting to trade that for aesthetics, 1080watts seemed like enough for us.

Sunpower panels are 60v which is great for the long cable run needed from the roof to the equipment room. Each panel is wired directly to a dedicated Victron 100/30 charge controller. This allows for optimal power extraction from each panel regardless of sun orientation and shading.

Monitoring - Victron CCGX is magic! It's connected to the BMS, Solar Controllers, Inverter/Charger and Current Shunt and the Internet. This was another reason that kept me with Victron equipment. With this I'm always able to keep an eye on the boats electrical system and know the current state of the batteries and draw on the system. It also keeps all the charge controllers in sync with each other.

I also have a Victron battery monitor with current shunt. This is redundant as the REC BMS also monitors current and reports battery state.

Life with so much power - 720Ah is really a ton of power. Its more unless unlimited to us. The solar produces 4-6kWh/day. Thats enough to make hot water using the inverter(I know we are spoiled) and do a load of laundry with 45 minutes of dry. We would never live like that if we didn't have such a surplus.

We only need run the generator if we need AirCon, ie guests visiting or its one of those rainy humid days and we just want to live a little. We can go about 4-5 days of normal living and no sun before we are forced to run the generator to re-charge. Normal sunny weather we go weeks at a time w/o running the generator.

Some other things - My house bank is isolated from the AGM engine mains. This is because I cannot control the charge voltage/current of the alternators and because the resting voltages of the LiFePO4 is typically much higher than the AGM. The mains AGM's receive a small charge from the inverter/charger via a dedicated starter output. This is enough to keep them topped off between motoring. Also the generator has a dedicated starter battery that is recharged from the generator. A left over battery coupling relay(factory installed) that originally linked the house bank to the mains bank when either banks voltage is above 13.2 was moved to connect the generator battery with the mains battery as another way to keep these batteries charged. If I did not already have this on the boat I would not have installed it.

I'm also planning on upgrading our 2000watt inverter to 3000watt so we can run a single AirCon unit for an hour each night to cool off and dry out our cabin before going to bed. This will also increase the size of the charger from 60A to 120A which will greatly reduce our re-charge time if using the generator.

In the future I also plan to add a Sterling battery-battery charger which will charge the LiFePO4 house bank from the starter bank while the engines are running. But the truth is we do not run the engines enough now to make me feel like we are missing out on a chance to charge our batteries.

[LilleVenn]

Originally Posted by Helia 44

Helia 44 here, now a Saba 50 from Australia.

I am somewhat of an honest EXPERT at this, and not biased by trying to sell you something. In my Business (and no I am not selling anything here) my Business is outfitting Bushtracker Caravans (4x4 off-road travel trailers in your language) for independent living in the Outback.. 22 years ago, when I started, I called them "Land Yachts" for the Outback... Trust what I have to say, this is neutral help for you with no bias for $$.

Thank you for sharing all the knowlege with us. It is really helpful to have an opinion of someone who has experience with such systems.

First, congratulation to your Saba. I've read a few of your post's thinking about the different possibilitys and now you have gone for it; very nice.

I apprechiate the notes why the generator fit your needs.
I am a glider pilot, and every time I have to start the engine on a flight because I'm to low to get home, I lost against myself. That may explain in another way why I do not want a generator. And then solar combined with litthium seems to be the best alternative for us.

[LilleVenn]

Originally Posted by Terbonium

Thanks, I'm happy to help and share what I've learned thru the process.

Battery Choice -
Charging and BMS -
Solar -
Monitoring -
Life with so much power -
Some other things -

Wow, what valuable replys from Helia44 and you, I'm impressed.

All I read from you let me think we are on very similar way to solve the electrical demands of the boat. You are going even one step further, having a generator on board, an still taking the effort to build an almost indipendent system; very remarkable

I will check the REC-BMS, the 123 SmartBMS I have on my testsystem does not fullfil all my needs.
I totally agree that your Solar with 3 panels is the best loocking, but since we do not want a generator, I may have to accept the overhang of 5.
CCGX; thank you for that one. I'll added it to my wish list.
Your section "Some other things" covers some points I still think about. At the beginning, we will leave the factory installed system (600Ah AGM, Victron 2000W) and add the lithium (1200AH) with a 3000W Victron MultiPlus. So I have the same problem with isolating the battery banks and the charging from the alternator. But if you think you'll add a sterling to do this job, I'll go for that too and forget about the Balmar alternator.
Thank you very much, I try to stay in contact.

[Terbonium]

Just got around to adding the REC-BMS to the system. This is the perfect match for anyone using Victron equipment with their custom built battery bank. So nice now that the REC directly controls the charge current and voltage of the Victron & MPPT controllers.

[MKB53]

Hi Terbonium, that is a great view of your installation.
I am keen to get more detail on how you networked the REC and Victron devices. Does the REC factory firmware support this or do they have a special version? I assume you used the Can bus? My install is pretty basic and I would like to connect the mppt and inverter/charger, battery protect etc as you have.
Even with the basic set up the BMS does a great job but won't help if there is a malfunction!

[Terbonium]

Originally Posted by MKB53

Hi Terbonium, that is a great view of your installation.
I am keen to get more detail on how you networked the REC and Victron devices. Does the REC factory firmware support this or do they have a special version? I assume you used the Can bus? My install is pretty basic and I would like to connect the mppt and inverter/charger, battery protect etc as you have.
Even with the basic set up the BMS does a great job but won't help if there is a malfunction!

Yes, the REC-BMS has a CAN Bus that connects directly to the CCGX with native Victron protocol support. (http://www.rec-bms.com/datasheet/Use...MS_Victron.pdf) It communicates the desired charge current, desired charge voltage, max discharge current and state of charge to the CCGX. The CCGX then instructs the Multi/Quattro and MPPT controllers over VE.Bus how to charge. For example, during Bulk, the CAN bus communicates 14.4V, and a max current of .6*Battery Capacity(there is a ceiling value as well). Then once the pack nears 100% and the BMS begins the balance low/high cells, the desired charge current drops to a value low enough that the BMS can bypass charge current from the high cells to lower cells. Once the BMS determines the pack is at 100% the desired charge voltage drops to the configured float voltage(as set in the BMS).

Because the battery protect only allows current flow in one direction I have it wired to only carry current to DC house loads. The MPPTs and Multi/Quattro are wired directly to the bank with no disconnect protection. I am relying on the CAN communication to stop discharge/charge of the Inverter & MPPT. This works, but probably not the safest solution. I will be replacing the Victron 220A battery protect with a BlueSea ML7713 relay which can handle current flow in either direction. Then the battery will be protected from charge and discharge sources by the BMS and relay.

I'd recommend contacting REC if you have any questions. Their support has been great. Their product is well built and worked exactly as advertised. Review the pdf doc in the link above. Everything is very clear and you can see all the options that can be configured in the BMS.

*edit

I belive CAN hardware support is optional in the 4 cell REC-ABMS. If ordered w/o it I'm not sure if it can be or how it is added.

[CatNewBee]

Originally Posted by Terbonium

Yes, the REC-BMS has a CAN Bus that connects directly to the CCGX with native Victron protocol support. (http://www.rec-bms.com/datasheet/Use...MS_Victron.pdf) It communicates the desired charge current, desired charge voltage, max discharge current and state of charge to the CCGX. The CCGX then instructs the Multi/Quattro and MPPT controllers over VE.Bus how to charge. For example, during Bulk, the CAN bus communicates 14.4V, and a max current of .6*Battery Capacity(there is a ceiling value as well). Then once the pack nears 100% and the BMS begins the balance low/high cells, the desired charge current drops to a value low enough that the BMS can bypass charge current from the high cells to lower cells. Once the BMS determines the pack is at 100% the desired charge voltage drops to the configured float voltage(as set in the BMS).

Because the battery protect only allows current flow in one direction I have it wired to only carry current to DC house loads. The MPPTs and Multi/Quattro are wired directly to the bank with no disconnect protection. I am relying on the CAN communication to stop discharge/charge of the Inverter & MPPT. This works, but probably not the safest solution. I will be replacing the Victron 220A battery protect with a BlueSea ML7713 relay which can handle current flow in either direction. Then the battery will be protected from charge and discharge sources by the BMS and relay.

I'd recommend contacting REC if you have any questions. Their support has been great. Their product is well built and worked exactly as advertised. Review the pdf doc in the link above. Everything is very clear and you can see all the options that can be configured in the BMS.

*edit

I belive CAN hardware support is optional in the 4 cell REC-ABMS. If ordered w/o it I'm not sure if it can be or how it is added.

congratulations, nice install. I have the classic REC ABMS set up without the can communication, but I like it too. Very versatile.

[john61ct]

Sounds great!

Are the REC setpoints user-adjustable?

[MKB53]

The REC BMS is fully configurable.

Like Terbonium I have found their support very good and prompt.

Now to take my installation to the next level.
I am more worried about and accidental full discharge than overcharging. Perhaps because it happened to me once before!

It sounds like the CCGX is a key component in managing the Victron devices.

[Terbonium]

CCGX makes it all happen They make a headless unit now, the Venus.. But, for the money, the CCGX makes total sense.

In fact, its bit above the scope of this thread, but I have our CCGX running in what Victron calls ESS mode. This balances our solar input with daily usage and grid power. Our marina meters usage so to limit our shore usage the CCGX allows the batteries to discharge nightly to a set level and then let them recharge from solar the next day. There is also a feature named "Battery Life" that adjusts this discharge level such that the bank is allowed to fully charge at least once per week. If the bank is run too low, the Victron will sip power from the grid to maintain a minimum level of charge(Sustain mode).

For us this allows a couple things:

1) We save a little $$ by using our solar even when tied to shore power. ($0.75 / day)!!
2) We are able to cycle our LiFePO4 bank. Leaving them at 100% for weeks at a time is not ideal.
3) A simple flip of a setting in the CCGX will force the batteries to 100% (we sometimes do this a couple hours before we set sail)
4) Because we have a Quattro, the generator is on a dedicated input. The CCGX knows the difference between generator and shower power inputs. If the Generator input goes high, it immediately tries to charge the battery to 100%.(no power sip like it does with shore)
5) We can limit the inverter power when on shore power. Even though the inverter can put out 3k, it would only last a few hours on batteries. To reduce unnecessary high current loads and heat we limit the inverter to 1kw when on shore power. Any demand above that will be drawn from the shore connection. This allows us to run our AirCon partially from the batteries, partially from the shore power. As the battery discharges and reach the low threshold as determined by the "battery life" algorithm, power will stop being drawn from the batteries and all drawn from shore power.