Low Budget Lifepo4 Experiences anyone?

[Franziska]

Thanks for your input.

We do not have alternators and Diesels :-) only (2x) 9.9hp Yamaha.

Charging will be from (4x) new 300w Solar, 1x Rutland 1200 Wind and our 2.6kW Genset as backup via the existing 50 Amp charger which is suitable for LiFePo4 according to the manufacturer data.
The genset will run the DIY desalinator too when not charging.

My work computer 300w will need to run mostly from a dedicated Honda EU 10i genset in low power Eco mode.

It's just to power hungry and we do not have space for more panels.

For those asking why not the big genset for the work PC, or a less power hungry PC?
The big genny is much to loud and I am working in computer graphics which needs the calculation power I have on the suped up laptop/desktop replacement I currently run.
One RTX2070 for now. A second to be added eventually...

I'm drawing up some schematics and will post them here, so that everyone can chime in once more :-)

Originally Posted by Dockhead

I'm not speaking from experience, so take this for what its worth (for the voice of real experience and deep knowledge -- make friends with Jedi and Newhaul ).


But I did a lot of research on this, and I think I can offer a few tips for you which could be useful:


1. This is absolutely worthwhile, with huge improvement in functionality, and if you plan to keep your boat for a long time, will actually be cheaper on the long run than lead-acid. There is just no question that this will make lead-acid batteries obsolete pretty soon.


2. Do NOT however assume that you can just throw together some cells and a BMS and away you go. You will need to do significant changes to your charging system and other aspects of the electrical system, to make these work well.


3. One change in particular concerns the alternators. If you don't properly regulate ordinary car type alternators, you will burn them up with lithium. And once you properly regulate them, they will have suboptimal output. You will want to think about upgrading these or adding second alternators.


4. Protecting the alternators in case one of the cutoffs is activated by BMS is a topic much discussed. There are different ways to do this; buffering via a lead-acid battery is probably the most common tactic. But you can also do this with one of those Sterling alternator protectors, which is the way I would do it.


5. You will have to forget most of what you know about operation of a lead-acid bank. Particularly important is the fact that lithium batts hate to be kept at full charge (unlike lead-acid which thrive on being kept at full charge). When you design your system, you will want some way to hold your battery at partial state of charge, when you don't need the full storage capacity (e.g., at dock). I have not seen a good solution for this. The right solution would be via the BMS -- if the BMS gave you a control for what % state of charge to stop charging. Then you just set it at 50% or whatever when you are at the dock or at anchor with abundant solar or whatever -- whenever you don't need the full capacity. And change it to 100% when you're about to leave for a long passage under sail where you want the full capacity.


Good luck, and let us know how you get on!

[newhaul]

Originally Posted by Franziska

Thanks for your input.

We do not have alternators and Diesels :-) only (2x) 9.9hp Yamaha.

Charging will be from (4x) new 300w Solar, 1x Rutland 1200 Wind and our 2.6kW Genset as backup via the existing 50 Amp charger which is suitable for LiFePo4 according to the manufacturer data.
The genset will run the DIY desalinator too when not charging.

My work computer 300w will need to run mostly from a dedicated Honda EU 10i genset in low power Eco mode.

It's just to power hungry and we do not have space for more panels.

For those asking why not the big genset for the work PC, or a less power hungry PC?
The big genny is much to loud and I am working in computer graphics which needs the calculation power I have on the suped up laptop/desktop replacement I currently run.
One RTX2070 for now. A second to be added eventually...

I'm drawing up some schematics and will post them here, so that everyone can chime in once more :-)

Your situation just begs for LFPs post your schematic and we will go from there.

[GoneDiving]

Originally Posted by zstine

Just wait to buy until you are ready to build/install/use.

+1. Especially if you are building a large bank.

Research actual delivery lead times in your country I ordered months ahead, thinking that hazardous goods transport and Customs into Australia would be time consuming. Wrong!! Everything arrived in a couple of weeks and prices have since dropped considerably.

I'd agree on being informed on the finer details if going the DIY route. An abundance of caution is good but realise many seem to delight in making the process seem much more difficult than it is. Know what features can be provided by your existing chargers, inverters etc so that you don't unnecessarily double up on equipment or items that could potentially shut down your vessel.

Good luck

[GoneDiving]

Originally Posted by Emmalina

Have you thought about fitting the active balancing modules they are cheap and WORK great !

Sorry, I just saw your reply.

Sure and they will be part of the larger pack. When my old lead batteries died I needed a replacement "now" and didn't want to buy new ones when I had the lithiums sitting in my workshop. I literally threw them in the battery box and they worked. Their capacity is such that it's easy to keep them below 80% state of charge where their voltages are nearly identical. They only drift at the top 5% of capacity and I don't need/use that anyway.

I'll top balance everything when the full pack is installed but so far I've been happy.

I should add that I'm using solar recharge so I didn't have the concerns about overloading alternators etc

[GoneDiving]

Originally Posted by newhaul

No need for active balancing top balance before commissioning and check balance annually. The likelihood of an out of balance issue is quite low considering our lowC charging and discharging rates.

Mine are still in balance at almost 2 years in .

Just keep out of the knees and no issue

Blasphemer!! You are being incredibly reckless, need to sip the CoolAide, and fit balancing immediately otherwise expect exploding cells, fireballs and other bad stuff. �� ��

Yes, I'm joking. On a more serious note, I did the same thing with a dive scooter battery. Yes Apples and Oranges but it is much more highly stressed, operates at much higher charge and discharge C rates and much deeper cycles. I monitor cell voltages but after 5 years have never needed to balance anything. What often isn't included in the discussion is that cell voltage isn't a accurate indicator of capacity. Lithium has a a very flat voltage curve and can accept considerable (dis)charge with no visible change to its indicated voltage.

I'd agree that a balanced set of well matched cells provides many discharge/charge cycles with very minimal cell drift even if no balancing is provided.

[Franziska]

Hi,

CAUTION LENGTHY POST ;-)

following the opening post of this thread and realising that LiFePo4 is actually within reach, meaning financially in a similar enveloppe as the better AGM & Lead Acid batteries I drew up some schematic and calculated our power usage.

All attached at the end as images & Excel file. Don't be to harsh I am not an Electrical Engineer.
If someone wants the Libre Office Draw Odg file, either to comment or to plan their own system let me know by PM or Email.
Regarding all files feel free to use or share them. Still I can give no guarantee though for it being correct and take no responsibility for terrible things which might happen from its use ;-)

When you read through this. Please keep in mind we are on a budget AND we are willing to take the small risk of getting 2-3 cells which need changing upon delivery.

At first some input on the boat and circumstances. Please be very specific when recommending equipment (= Links or exact model numbers) or answering. Refer to our usage numbers please. THANK YOU!

THE BOAT:
See attached picture.

CIRCUMSTANCES:

1. We (my boyfriend and myself) will live more or less permanently onboard.​
2. We intend to cruise only in warm climates.​
3. We are from Europe, so our AC system is geared towards 220V and ideally we buy stuff from European suppliers., but I have little hesitation to buy from China too.
   
4. Typically (80-90% of time) we are preferring to anchor instead of going into marinas.​
5. We are on a budget & prefer to change only the components we really need to change to make the planned system with the LiFePo batteries work.​
6. Our current batteries are pretty much shot and as space & weight are equally an issue as budget is, we intend to get 2-3 sets of these: https://bit.ly/3cRAiJr as recommended in this video https://bit.ly/3r8wOHN.​
   At 460€ per set including shipping to Germany they beat AGM and Lead Acid easily.
   We are aware that there may 1-2 faulty cells in the delivery which might need immediate replacing, but feel its a risk worth taking.
7. Our current system is completly 12v. As we do not intend to run high current items from the batteries, we currently do not intend to switch to a 24v system.
8. As I am still working in computer graphics (www.das3Dstudio.de) and will continue doing so from the boat, I need to power my high performance PC.
   We thought about doing this with solar, but, the power draw will be to much. We will use solar though for our house battery system.
   A less power hungry machine is not an option, quite the contrary, I may eventually need to add a second external RTX2070 graphics card.
   So looking at other options, we decided to get a small Honda EU 10i genset dedicated to this.
   It will be much more quiet than our main genset, as it can power the PC in Eco mode.
   Fuel is not an issue either, as our main engines as well as the main genset run from petrol anyway.
   We will eventually add a third LiFePo4 pack to run the work PC occassionally overnight.
9. We do NOT have diesel engines and alternators.​
10. Batteries will be located on the bridgedeck but within living quarters, so lead acid is pretty much out as a solution.​
11. We do want to keep our existing fridge ;-)​
12. We will add the separate freezer.​
13. Our current genset is fine for running the desalinator and power tools or even a heater, but it is to loud to run the work PC over extendet times.​
14. The Starlink antenna is planned in for business later, but currently not yet available for mobile platforms and their planned mobile unit might be slightly different. Currently they say the antenna daws 100w.​

QUESTIONS (Please suggest specific models & (possibly European) suppliers if you can):
BMS
a)
We need a battery management system (BMS) for our batteries. Our intendet battery packs have 280Ah each. Charging will happen mainly via the four solar panels and the windgen.
Is this one https://bit.ly/2QlydxL suitable? I'm not sure because it says 120Amp.
b)
I understand we need to „top level“ the cells before starting to use them. Should/do we need to also install an auto leveller?
We prefer to have less risk of breaking something if we forget to to switch something on.

SOLAR CONTROLLER
a)
We have two Sunware Fox100 Solar controllers from our old solar panels. Do we absolutly need to change those, or can they be reused with the new 300w panels?
b)
If we need new controllers what are suitable controllers which are good but do not carry the pricetag of the Victron units? Please suggest specific models suitable for our set up with four 300W panels. Remember we are on a budget.
c)
Do we need one solar controller per panel?
d)
Our Rutland 1200 Windgen controller (Manual here https://bit.ly/394RuKC) has a solar controller terminal too and can accept up to 20A from the panels.
Can/should we use it to also control at least one of the PV panels?

SOLAR PANELS
For now we will get 4 new 300w panels.
We have no issue using industrial grade panels as long as they are saltwater proof (which they also need besides Highways...). We prefer hard non flexible panels. Can be fairly large, but removable might be better if we go to the Caribbean and need to demount for hurricane storage.
Open to suggestions.
While looking into this, I found this pretty handy site by the European Union: https://bit.ly/316K2Kg
Some may find this helpful too.

CHARGER
We currently have a Dometic Waeco 1250 50A charger to charge via Genset or Shore power. It can handle 220V & 110V AC input.
a)
Do we need to upgrade it?
As far as I understand it can be used for LiFePo4 charging when the dip switches are set accordingly.
b)Usually we plan to charge from solar and wind, the charger is a back up. So 50A from it should suffice. We would need to run it longer, but as contingency?
c)
On the odd occassion on which we are actually in port we are usually docked for several days, so the 50A charging should suffice, no?
d)
LiFePo4 are said to pose less risk fire/explosion risk than standart LiPo batteries.
Still, is it a good idea/a necessity to use a metal battery case?
Maybe with a non combustible insulation of glass cloth inside facing the battery cellsß

STORAGE
What happens if we need to leave the boat over an extendet period?
In the past with AGM we could simply leave the batteries hooked up to solar. Is that possible here too? Or should it be done different?

[mitiempo]

Franziska

If you are going with a drop in battery system - eg Battleborn - your existing Dometic charger will work. But if you are going with raw cells DIY it will not unless your BMS can shut it off. LiFePo4 does not want absorption and float. Charge to a voltage - typically 3.65 per cell (14.6 volts) or in my case 3.55 (14.2 volts and then stop. LiFePo4 will fully charge and overcharge even if a lower voltage is continued for a long time. I know of no chargers where absorption is adjustable. The manufacturers are not always aware of what is required to charge LiFePo4. For example the Promariner PronauticP has a lithium setting that is a disaster, the good news is that it has a custom program but still doesn't have adjustable absorption voltage and time.

The same applies to your solar. You need a BMS to shut it off when the target voltage is met. Victron MPPT can be remotely shut off with a built in switch if it is a large one or with a VE Direct cable if a smaller one.

The wind gen is tougher because you need somewhere for the current to go when it is diverted from the LiFePo4.

The BMS I posted about earlier is not expensive. It has the capability to shut off charging sources if they have this option. It also has cell balancing built in. It also is a solar controller with optional inexpensive modules if your solar system is matched to your battery bank. In other words 24 volt panels for a 24 volt battery bank.
https://electrodacus.com/

[evm1024]

Just got 12 of the LF-280 cells delivered today. Ordered Jan 20th, delivered March 21 to USA/PNW. In a prior post I gave the link but here it is again:

https://www.aliexpress.com/item/1005...41be4ffeNGSNju

They are currently (no pun intended...) on the bench getting a top charge. There were packed well and arrived in good order. The voltages were 3.290 +/- 10 mv for the 12 of them.

All in all I'm happy with the supplier. This is one that Will P. recommended.

They are intended to replace the Winston 700 AH bank that has been on the boat for the last 7+ years in prep for 5 years cruising.

I'm likely to document how we set them up either here on CF or on our blog or both. No hurry.

I am still toying with the idea to buy another set of 4 to bring the house bank up to 1120 AH. Most likely I will do that.


Also - folks I am thinking we need a new thread entitled "If you want to be taken seriously in a LiFePO4 thread don't do this".

My first "rule" would be to "Don't conflate Li ion with LiFePO4" or some such. If you like the idea please feel free to send suggested rules to me.

[newhaul]

Originally Posted by evm1024

Just got 12 of the LF-280 cells delivered today. Ordered Jan 20th, delivered March 21 to USA/PNW. In a prior post I gave the link but here it is again:

https://www.aliexpress.com/item/1005...41be4ffeNGSNju

They are currently (no pun intended...) on the bench getting a top charge. There were packed well and arrived in good order. The voltages were 3.290 +/- 10 mv for the 12 of them.

All in all I'm happy with the supplier. This is one that Will P. recommended.

They are intended to replace the Winston 700 AH bank that has been on the boat for the last 7+ years in prep for 5 years cruising.

I'm likely to document how we set them up either here on CF or on our blog or both. No hurry.

I am still toying with the idea to buy another set of 4 to bring the house bank up to 1120 AH. Most likely I will do that.


Also - folks I am thinking we need a new thread entitled "If you want to be taken seriously in a LiFePO4 thread don't do this".

My first "rule" would be to "Don't conflate Li ion with LiFePO4" or some such. If you like the idea please feel free to send suggested rules to me.

Where is your boat moored?

[newhaul]

Originally Posted by mitiempo

Franziska

If you are going with a drop in battery system - eg Battleborn - your existing Dometic charger will work. But if you are going with raw cells DIY it will not unless your BMS can shut it off. LiFePo4 does not want absorption and float. Charge to a voltage - typically 3.65 per cell (14.6 volts) or in my case 3.55 (14.2 volts and then stop. LiFePo4 will fully charge and overcharge even if a lower voltage is continued for a long time. I know of no chargers where absorption is adjustable. The manufacturers are not always aware of what is required to charge LiFePo4. For example the Promariner PronauticP has a lithium setting that is a disaster, the good news is that it has a custom program but still doesn't have adjustable absorption voltage and time.

The same applies to your solar. You need a BMS to shut it off when the target voltage is met. Victron MPPT can be remotely shut off with a built in switch if it is a large one or with a VE Direct cable if a smaller one.

The wind gen is tougher because you need somewhere for the current to go when it is diverted from the LiFePo4.
l]

Brian I actually do know of one charger that the absorption is adjustable via the return amp
Which are adjustable from 0 to 20 amps normally set to 2% to 4% of bank capacity.

My solar charger cut out point is adjustable as well and set to 13.8v stop.
Most wind generator control modules are adjustable
Alternatively you can use a dc waterheater element as a dump load .

Snapshots from my trace 2512 owners manual .
It does it if I'm reading correctly.

[mitiempo]

Originally Posted by newhaul

Brian I actually do know of one charger that the absorption is adjustable via the return amp
Which are adjustable from 0 to 20 amps normally set to 2% to 4% of bank capacity.

My solar charger cut out point is adjustable as well and set to 13.8v stop.
Most wind generator control modules are adjustable
Alternatively you can use a dc waterheater element as a dump load .

Snapshots from my trace 2512 owners manual .
It does it if I'm reading correctly.

It looks like it is adjustable, but as it states if there are any loads - and with refrigeration etc on a boat there almost always is - it will stay in bulk longer.
And you really do not want a float at all with LiFePo4.


I think my preference is a BMS that kills charging when terminal voltage - eg 14.2 or 3.55 per cell - is reached.

Some solar controllers are adjustable - Victron are fully adjustable. But again I think a BMS that shuts it totally off when a given voltage is reached is a better way to go.

As a matter of fact almost all Victron chargers, inverters, and solar controllers can be remotely shut off. In my case by the BMS.

[newhaul]

Originally Posted by mitiempo

It looks like it is adjustable, but as it states if there are any loads - and with refrigeration etc on a boat there almost always is - it will stay in bulk longer.
And you really do not want a float at all with LiFePo4.


I think my preference is a BMS that kills charging when terminal voltage - eg 14.2 or 3.55 per cell - is reached.

Some solar controllers are adjustable - Victron are fully adjustable. But again I think a BMS that shuts it totally off when a given voltage is reached is a better way to go.

As a matter of fact almost all Victron chargers, inverters, and solar controllers can be remotely shut off. In my case by the BMS.

But I almost never have shore charging running I'm all solar and wind .
Shore and alternator are backups and monitored closely

[UFO]

Originally Posted by mitiempo

It looks like it is adjustable, but as it states if there are any loads - and with refrigeration etc on a boat there almost always is - it will stay in bulk longer.
And you really do not want a float at all with LiFePo4.


I think my preference is a BMS that kills charging when terminal voltage - eg 14.2 or 3.55 per cell - is reached.

Some solar controllers are adjustable - Victron are fully adjustable. But again I think a BMS that shuts it totally off when a given voltage is reached is a better way to go.

As a matter of fact almost all Victron chargers, inverters, and solar controllers can be remotely shut off. In my case by the BMS.

BMS should be the last line of defence and should only ever intervene in an emergency high or low voltage situation (AKA Something else has failed). If your chargers etc can not be set correctly simply get ones that can.

[Franziska]

@mitiempo & @newhaul

We are at anchor most of the time.

Looking at the prices of the Battleborn and similar and the fact that a charger can most likely continued to be used when the LiPoFe4 are due for replacement in 8-10years, I think we rather go with the reasonably priced raw cells and buy a new charger.
Can you recommend a specific model which would fit our numbers?
Is there something similar to a Victron around at a lower price tag, or is there really not much choice?
Keep in mind we really will use the charger only when charging from the genset or the shore connection. In both cases I accept that charging may take longer on a less costly charger. Still, we need to keep the budget down.
Hopefully we can still sell the used Waeco 1350 for a reasonable price along the way.

Regarding BMS or MPPT shutting off any supplies once a certain voltage is reached, does that need to be done manually, or can that be made to happen automatically?
We do not want to kill the batteries when we forget to hit a button.
What BMS specifically would you recommend when looking at our numbers and the fact that we are on a budget? Is the one from Alibaba which you posted earlier good for us? Is it correct that we need one for each 280A four cell block?

Do we need one MPPT per panel (most likely they will be large 48V industrial ones)? So we probably have to sell our Fox100 controllers too.

The windgen has a control which can be set to switch it off via reversing its polarity internally once it senses a given voltage at the battery.

Sorry to bug you, but you seem fairly knowledgable on the subject (as are some of the others as well.)
Thank you!

[wholybee]

Originally Posted by Franziska

@mitiempo & @newhaul

We are at anchor most of the time.

Looking at the prices of the Battleborn and similar and the fact that a charger can most likely continued to be used when the LiPoFe4 are due for replacement in 8-10years, I think we rather go with the reasonably priced raw cells and buy a new charger.
Can you recommend a specific model which would fit our numbers?
Is there something similar to a Victron around at a lower price tag, or is there really not much choice?

I bought a Renogy 20A LifePO4 charger. I would rate it on the low end side of the scale. I don't have a generator, so I will use it very rarely. If I were to depend on it I would look at something else. Sterling Power makes a good charger that is an alternative to Victron.

Originally Posted by Franziska

Regarding BMS or MPPT shutting off any supplies once a certain voltage is reached, does that need to be done manually, or can that be made to happen automatically?

Almost any BMS will cut off charging once a certain voltage is reached. Better ones you can set that voltage. It would only be the expensive high end BMSs that will send a signal to turn off a device or charger.

Originally Posted by Franziska

[B]What BMS specifically would you recommend when looking at our numbers and the fact that we are on a budget? Is the one from Alibaba which you posted earlier good for us? Is it correct that we need one for each 280A four cell block?

I bought an overkill solar BMS. Overkill and Daly see to be the BMS's of choice unless you are willing to spend a lot of money for a high end BMS. Overkill is distributed in the US with good support and a warranty. No, you do not need one for each set of 4 cells, as you can parallel several cells before you series them. My battery is 3p4s. I am not using the commodity 280Ah cells. If I were using cells that were more likely to fail, I think I would use multiple BMSs. By using multiple BMS's you also gain some redundancy and can support higher loads.

Originally Posted by Franziska

Do we need one MPPT per panel (most likely they will be large 48V industrial ones)? So we probably have to sell our Fox100 controllers too.

No, you do not need one controller per panel, however you get a slightly better output if you do. Especially if a panel will be in the shade.