Replacing a bank of AGMs with LiFePO4s on a sailboat in Europe

[sailing gal]

Newbie here. I am looking for some advice, please? I have an American sailboat, with 5- 5 1/2 year old Lifeline 105 Ah AGMs that are basically now down to about 25% capacity. Multiple conditioning charges have not helped, and I am rather disappointed that they are failing so early given that I treat them extremely gingerly. So, I am looking at replacing them with a Lithium ion bank. The problem is... I am currently in Europe and if I were in the U.S. I would probably purchase the Battle Born batteries as drop in replacements. Here, I have located what looks to be the UK equivalent of the Battle Born batteries- Lifos: which are also drop-in substitutes for AGMs. I have spoken to them on the phone and they claim that I will have no issues with my charging system, my 100 Ah alternator on the engine, and the Wind generator and 400W of solar panels that I also have which are controlled with a Skye MPPT controller. But, we are talking about a fair amount of money for the 4- 105Ah batteries that I can connect in parallel. The Lifos are each about $250 more than the Battery Born. Meanwhile, I have a friend here who is a marine electrician who is telling me that I am being ripped off because I can buy lithium batteries with BMS systems so much cheaper from China. I am extremely hesitant to purchase a bunch of batteries from China, even though they claim to have similar BMS systems. Just wanting a second or third or fourth opinion, please?

Thank you in advance.

 

[Popuptoaster]

I replaced 4 dead lead acids with just one 24v LiPo4 which helped with costs, despite having half the rated capacity of the old batteries I am getting more power overall. I hesitate to reccommend the one I bought just yet though as I am not sure the BMS is functioning as it should and I am waiting for a reply from the seller.

I am in the UK, I bought one of these, but as I say, I'm not recommending it just yet, link is for price comparison and info only.

Ultramax LI100-24, 24v 100Ah LiFePO4 Lithium Iron Phosphate Battery

Ultramax LI100-24, 24v 100Ah LiFePO4 Lithium Iron Phosphate Battery for Solar Panel, Motorhome, Caravan, Off grid, Inverter, Large Electric Vehicle: Electric golf carts, Buses, Electric Cars, Sightseeing Cars and Hybrid vehicles. Light Elctric Vehicle: El

www.batterymasters.co.uk

 

[Silentpower]

Good point made above. You had 4 agm batteries in parallel giving you 420ah (around 4800wh) of capacity, of which realistically 210ah is usable. This is because, as you know, to achieve reasonable lifetime of lead acid, you should only discharge to half capacity to avoid sulfation. So if you have been doing this, you usage is really 210ah (2500wh) . With lithium the depth of discharge can be deeper ie, you use more of the advertised capacity therefore you can replace your 4 agms with 2 lithium batteries. It's important to gauge your actual usage as if you have actually been using the full 420ah of your agms, then this is what you'll need to cater for. Hope this makes sense.

 

[Silentpower]

One other thing, be sure to check your charge voltage. Agm's are very easily damaged by over charging, even just slightly high voltage. This causes gassing and therefore loss of precious electrolyte. Check the system before connecting expensive replacement just incase of a hidden fault which may be damaging.

 

[sailing gal]

Yes, thank you, I understand this. However, in doing the upgrade, I am interested in upping the Ah available for my equipment, that is why I am looking at 4 of those Lifos 105 batteries. My entireboat system is 12V, so not looking for a 24V system.

 

[sailing gal]

One other thing, be sure to check your charge voltage. Agm's are very easily damaged by over charging, even just slightly high voltage. This causes gassing and therefore loss of precious electrolyte. Check the system before connecting expensive replacement just incase of a hidden fault which may be damaging.

I recently replaced my charger, so I know that what I have now is working perfectly. My old charger was actually undercharging somewhat- but it was also almost 20 years old.

 

[Silentpower]

It's worth trying to figure out why you didn't get the expected lifetime from the agm batteries.

 

[Silentpower]

Yes, under charging could well have been the cause of early agm failure.

 

[sailing gal]

It's worth trying to figure out why you didn't get the expected lifetime from the agm batteries.

I agree. Unlike other AGM batteries, Lifelines like to be conditioned/equalized annually and I did not know this. So, it is possible it just sulphated too much. I have contacted Lifeline and that was their best guess. I suppose it could have been a charger issue. I don't know. It was charging up to voltage, but when a load was put on them, the voltage dropped like a rock.

 

[sailing gal]

At any rate, they are going to go and I would like to install LiFePO4 batteries. Just hoping someone here has some experience with the Lifos. Apparently their 105s are fairly new on the market. Once I have new ones in place, I can dissect one of the AGMs and take a look.

 

[Silentpower]

I had over 7 years experience with agm, I made the switch to lithium and sleep easier now lol, but I'm off grid with no means to charge other than the sun.

 

[Ampster]

I shared your initial scepticism. After reading the threads here I felt the cost benefit was worth the risk. I used one of the vendors recommended here to mitigate the quality risk.
I don't know what the import duties are in the EU but others may know. I have used credit cards and PayPal which give me comfort about the financial risk.
Read the thread about importing from China and specify DDP in Trade Terms and you can get a quote for goods delivered to your doorstep (or to your transom) with all duties and taxes paid.

 

[Sparky trader]

I have been in the solar and wind installation trade for over 35 years now and each day I learn something new.
When I was a very young sparky I thought I knew it all about batteries. After 20 years I realized I didn't know it all due to my experiences of how fast technology "SOMETIMES" improves but always changes. Know I can comment on what experts used to know from lots of experience.
As it goes for the different makes of new LiFePO4 batteries it is very hard to say that a particular make is the best because tomorrow there is a even better make out there for less money and almost certainly more power storage. These batteries are relatively new in the common market place (just a few years) so the test of time from any brand is almost impossible as all Battery companies are trying to keep up with improvements as they have sufficient tests done in the labs. The LiFe battery technology has been in testing stages for quite a few years though.
Without going into too many details about what I have learned about LiFePO4 there is one thing that is important. Over voltage or over heat kills them quickly.
Unlike AGM , GEL or standard 12Volt lead acid the 6 cells balance out generally when the charging is done / LiFe 12Volt batteries (having 4 cells in series) of all types require a some type of voltage control between the cells when charging.
A simple example is a LiFe 12V battery charging near the finishing full stage at 10 Amps (each one of the 4 cells may not be able to take all that 10A without going over voltage!) Thats where electronics looking at the cell 4 different Amps /volts & temperatures are required to balance the 4 cells. Commonly known as the BMS.

Since we are discussing quality of Lithium batteries This type of BMS is very important because some built in or separate BMS only take all the cells voltage/ Amps and temp together and only offer overall general protection without controlling each 3.2v cell. Thus shortening overall life due to temp, voltage or charge capacity imbalance. So a good BMS with temp and volts control to each cell is fairly important.

Quality of the cells? Well this is still getting better as each month passes. The Chinese do seem to have the largest range of these batteries but they are made all over the world. I can't really say any particular country makes a better cell than another as my research/experiance does not stretch far enough. I will say that the ELECTRIC CAR industry has driven improvements in making the cells thinner & lighter with better power outputs.
So this is opposite of lead acid where the heavier lead battery is normally better. LiFe batteries are generally getting lighter and better capacity because they are spraying the thin lithium and carbon coatings on the cell plates using a vacumm system to create more powerful cells that are said to be stronger (Time will tell when they reach the "too thin limit" but they seem to be getting smaller like electronics have become)
Different cell quality? The EV (car industry) appear to categorize them into 3 types
(1) Li-ion High Energy (2) Li-ion High Power (3) Li-ion Very High Power
The first (1) giving the best stored and delivered energy (by weight) and the last giving the worst storage (by weight) but best high amperage on demand.
On a solar system I would prefer the type (1) High Energy which appear to hold double the charge capacity per Kg. If higher amperage output is required like an EV car? then I would chose the type (3) V-H-Power would be used. Generally your battery (or cell) specifications will give you max power draw so this is a fair indication of max amperage power discharge. If weight is not important then this makes little difference as they are all generally about 95% energy efficient or better.

There is some 12V Li-Fe batteries that use a load of round cells and some use a load of flat looking cells known as PRISMATIC cells.
Round 3.2v, Li-Fe cells are the about size of "AA" normal 1.5v cells used in toys etc. There has been small amount of individual round cell failure which creates diminished overall battery life unless it is dismantled by an expert & changed out for a new round cell.
Flat, thinner & lighter "Prismatic cells" seem to be the future way for electric cars and these are generally accepted as more reliable and stronger with more flexibility from impact compared to the round cells.
Price differences per different types of cells are not large.
Summery to get best quality!
(A) Good BMS that controls voltage and temp between cells.(Bluetooth or Ethernet cable OPTION system helps inspect that the cells are in limits)
(B) Prismatic (flat) cells are a newer technology.
(C) lighter battery is possibly newer or better power to weight ratio.
(D) The country OR company you buy it from defiantly affects your guarantee if something goes wrong.
(E) More money definitely does not mean better quality so get customer reviews if possible.
(F) Various Batteries in series or parallel should have a BMS communication between so that one battery does not charge before the other. This helps keep the separate complete batteries balanced.
(G) China e-commerce sites show 12Volt 100AH LiFePO4 batteries with BMS and blutooth cell info etc, as low as 70 to 150 usd.
I would love to see what these batteries look like inside and what BMS (if any) protection is inside them. Mostly I see the retail about 5 times this price and up to 10 times for very similar specs.
Finally : It's hard to be an expert on new technology!

 

[sailing gal]

Thank you for all of this information. I am still researching for replacement batteries. I got a quote from Battery Born, but shipping to Europe with freight, duty and taxes makes this a costly proposition at least 50% higher than the bank. I have been reluctant to purchase from a Spanish company, which is where I am docked now. However, I have found a company that looks quite interesting to me, and sells LiFePO4 batteries with BMS and prismatic cells: www.masterbattery.es. They appear to be similar to Battery Born in that they would be drop-in replacements for my AGMs. The batteries are manufactured in Bulgaria. Since I am still a newbie, I was wondering if anyone out there with alot of time on their hands would mind taking a look at their UE-Bluetooth series (if you click on "Idioma" on the right side of the home screen you can choose English).

 

[sailing gal]

Thank you for all of this information. I am still researching for replacement batteries. I got a quote from Battery Born, but shipping to Europe with freight, duty and taxes makes this a costly proposition at least 50% higher than the bank. I have been reluctant to purchase from a Spanish company, which is where I am docked now. However, I have found a company that looks quite interesting to me, and sells LiFePO4 batteries with BMS and prismatic cells: www.masterbattery.es. They appear to be similar to Battery Born in that they would be drop-in replacements for my AGMs. The batteries are manufactured in Bulgaria. Since I am still a newbie, I was wondering if anyone out there with alot of time on their hands would mind taking a look at their UE-Bluetooth series (if you click on "Idioma" on the right side of the home screen you can choose English).

Correction to above, I was told that they were prismatic, but I could not confirm that at their website.

 

[sailing gal]

Correction to above, I was told that they were prismatic, but I could not confirm that at their website.

Correction to the correction----- their data sheet says: "The batteries are supplied with a LiFePO4 Battery Management System (BMS) that can monitor and optimized each single prismatic cell during charge & discharge, to protect the battery pack overcharge, over discharge, short circuit. Overall, the BMS helps to ensure safe and accurate running. " These are the Master Battery 200 Ah batteries. Actually, they sound the most technologically advanced of the batteries I have looked at.

 

[Ryang]

Have a look at this thread

Why so cheap?

What's wrong with these batteries? Someone here recommended RJ Energy and I reached out to them about their pricing I got this today: This is Alice, nice to meet you! Please check out our Best Price for you: For 12V 100Ah LFP battery, USD295 per unit. For 12V 200Ah LFP battery, USD585 per...

diysolarforum.com

May be an option for you. Has PayPal so it’s a safe transaction. Great price.
I haven’t looked at their stats sheet though.

Do your own research