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

[GoingWalkabout]

Originally Posted by transmitterdan

Chaya,

The reality is that you would have to cover your boat entirely in solar panels to create enough energy in a 10 hour day to run air conditioning 24/7. Even to run AC at night requires an enormous solar array.

Battery bank required to run 20K BTUs of AC for 8-10 hours is about 10-15kW hours. For LiPo it would require about 1,200AH bank. And it would take 1000W of solar a couple days to fully charge.

For the vast majority of cruisers on 40-50 foot boats running AC from solar is still a futuristic endeavor. Someone will jump on and tell you they do it but for most of us it isn't practical.

Thanks transmitterdan. Looking at your figures I think solar AC on a larger cat is doable.

First I'm not looking for 10 hours but rather max 8 hours.

You said it would take 2 days with 1,000W of solar power to charge the 1,200AH battery pack I would need. Well. I can have 1,800W on the back augmented with two 100W flip up panels on the life lines. Giving me 2,000W of solar power.

As far as the battery bank. 1,000AH can be bought from $1,400 to $2,700 weighing in at 30Lbs. Size and weight wize I could easily have 2 X 1,000AH's

Here is a link for a 1,000AH LifePo4 battery. So funny the emotion it drew just because I had the cheek to ask about such a battery.

https://m.alibaba.com/product/157048...7009.84.2euCXE

[evm1024]

Originally Posted by GoingWalkabout

I humbly apologize. I didn't think I was demanding anything from anyone.

Don't let the ун культивируют get to you. Keep asking questions and learning as you go.

[darylat8750]

Originally Posted by GoingWalkabout

Thanks transmitterdan. Looking at your figures I think solar AC on a larger cat is doable.

First I'm not looking for 10 hours but rather max 8 hours.

You said it would take 2 days with 1,000W of solar power to charge the 1,200AH battery pack I would need. Well. I can have 1,800W on the back augmented with two 100W flip up panels on the life lines. Giving me 2,000W of solar power.

As far as the battery bank. 1,000AH can be bought from $1,400 to $2,700 weighing in at 30Lbs. Size and weight wize I could easily have 2 X 1,000AH's

Here is a link for a 1,000AH LifePo4 battery. So funny the emotion it drew just because I had the cheek to ask about such a battery.

https://m.alibaba.com/product/157048...7009.84.2euCXE

Your post does not indicate that you understand that you will need 4 of those for a 12 volt battery bank. So 4X30 pounds and 4X$1400 (to $2700) for 12 volts.

Those are impressive batteries. There is information on the thread that indicates that cells over 200 amps each have internal strength that may create reliability issues although several banks are in use with 400 amp cells with no reported issues so far.

[GoingWalkabout]

https://m.alibaba.com/product/157048...y-Lithium.html

$1,490 3.2V 1,000AH

[GoingWalkabout]

Originally Posted by darylat8750

Your post does not indicate that you understand that you will need 4 of those for a 12 volt battery bank. So 4X30 pounds and 4X$1400 (to $2700) for 12 volts.

Those are impressive batteries. There is information on the thread that indicates that cells over 200 amps each have internal strength that may create reliability issues although several banks are in use with 400 amp cells with no reported issues so far.

Yes of course you are correct. I will need a bank of 4. But that is one heck of a power bank. No need to worry about having to spill out piwer. Also could be great for heavy use days with light use days in between.

[GoingWalkabout]

Another supplier of the Winston LifePO4 1,000 AH batteries.





LFP1000AHC

WB-LYP1000AHC LiFeYPO4 (3.2V/1000Ah) Special product
$1,326.45 List price:
$1,313.31 Order over 750.00 USD :
$1,287.02 Order over 3,500.00 USD :



High power lithium cell, original Winston Battery product with LiFePO4 (LiFeYPO4) technology. Capacity: 1000Ah, size: 356x560x130 mm, weight: 42 kg. Model: WB-LYP1000AHC(A)
Large capacity lithium cell LiFePO4/LiFeYPO4 - 3.2V/1000Ah

Note: this is a special order item with a limited promotional offer. The price quote is valid only for limited stock supply for small order quantities up to 16 cells. Please contact us for quotes for larger quantities.

Professional lithium cell for energy storage and other high power applications. Produced by the Winston Battery company (formerly Thunder-Sky) – product codes WB-LYP1000AHC, TS-LFP1000AHC, TS-LYP1000AHC. The large capacity monolithic cell – consists of a single cell structure.

Store easily large amounts of electric energy in the most safe and secure lithium technology.
High energy efficiency: minimal loss of energy during the charge and discharge cycle.
Long time reliable performance over many years. The cells have very high internal stability and well work for many years and decades.
High cycle life: the cell support thousands of cycles 3000, 5000, 7000, or more.
Reduced toxic risks: no acid electrolyte, no dangerous gasses during normal operation, low fire risks
High power applications: extreme power rating for short time discharge current - up to 10C (thousands of Amperes)
High power rating for deep discharge cycles – support discharge currents of 3C continuously.
Minimal self-discharge rate - no memory effect – the energy charged to the cell will stay for many months. The cell can be charged at any state of discharge.

The high capacity cells are especially suitable for making battery banks. It is very easy to make a battery bank of 12V, 24V or 48V. The large capacity cells reduce the need for cabling and make the installation very stable.


Basic technical specification
Nominal voltage of the cell is 3,2 V and the operational voltage is 2,8 V - 3,8 V.
The maximum charging voltage for initial charge is 4 V.
Recommended subsequent charging is to 3.8 V.
The minimum voltage is 2.5 V.
Maximum discharge current is 3C continously.
Operating temperature -45°C up to 85°C (discharging)

[GoingWalkabout]

Another option that costs a little more per AH is the 400AH 4 x 400AH will give your a 12v 1,600 AH bank. Cost just over $US 2,000





You could also go set up a very high capacity 4 x 700AH giving you a 12V 2,800AH bank. Cost just under $US 3,600

Like everything in the world of electronics. Prices are falling.


Pricing information taken from a European distributor.

EV-Power | Winston (40Ah-1000Ah)

[Jd1]

Another option that costs a little more per AH is the 400AH 4 x 400AH will give your a 12v 1,600 AH bank. Cost just over $US 2,000


No, it will give you a 12V 400AH bank!

[GoingWalkabout]

Originally Posted by Jd1

Another option that costs a little more per AH is the 400AH 4 x 400AH will give your a 12v 1,600 AH bank. Cost just over $US 2,000


No, it will give you a 12V 400AH bank!

Thank you. Still learning. So if I want to get my 1,000AH at 12V I will need to buy the 1,000Amp x 4 costing me about $5,000

Again thanks.

[Maine Sail]

Originally Posted by GoingWalkabout

Another option that costs a little more per AH is the 400AH 4 x 400AH will give your a 12v 1,600 AH bank. Cost just over $US 2,000





You could also go set up a very high capacity 4 x 700AH giving you a 12V 2,800AH bank. Cost just under $US 3,600

A 4S pack means series wired cells........ 4 X 400Ah cells in series is 400Ah. 4 X 1000Ah cells in series is 1000Ah's..

Originally Posted by GoingWalkabout

Like everything in the world of electronics. Prices are falling.

The Winston cells are more expensive today than when I ordered mine in 2010.. I have not noted much if any price drop on LFP prismatic cells. With fewer players in the prismatic market the price has actually bumped up a just bit over the last six years or so, and in some cases remained flat, but I've not noted price drops on large prismatics. I have noted some drops on 18650 size cells but those are the size of a "C" battery and a real nightmare to build house banks from...

[exMaggieDrum]

Originally Posted by GoingWalkabout

I humbly apologize. I didn't think I was demanding anything from anyone.

You don't need to apologize to the "humble" posters. IMO your posts were not demanding in any way. The posters mean well but said it in a mean way. This is a demanding subject though and you have a lot of homework to do on your own which will lead to many, many detailed puzzles and questions. You have to start with the basics of batteries, e.g. series and parallel, amp hrs from cells in series and those in parallel, etc. You may already be past that but this is just an example.

[GoingWalkabout]

Originally Posted by exMaggieDrum

You don't need to apologize to the "humble" posters. IMO your posts were not demanding in any way. The posters mean well but said it in a mean way. This is a demanding subject though and you have a lot of homework to do on your own which will lead to many, many detailed puzzles and questions. You have to start with the basics of batteries, e.g. series and parallel, amp hrs from cells in series and those in parallel, etc. You may already be past that but this is just an example.

Thanks for that. I wish I was past wiring of the bank in series or parallel.

From what I've been able to learn so far is that when you first set up your bank for balancing you wire them in parallel. After balancing you then in wire the parallel and connect in series.

Then I found out some are wiring in both series and parallel. When I thought I had it worked out I find something that makes my head spin. So yes. I have a lot to learn. I just hope what I'm learning is correct.

Another example of perplexity for me is wiring of the panels. I thought I had it worked out in order to have the least effect of shedding I should wire the panels in series. I saw a few YouTube demos on this. Then just today I saw a YouTube video from a solar company where they said wiring in parallel is best for shedding.

I know wiring in serial increases the amperage which increases the wire thickness you need to use but if you work from the premise of wiring for optimal performance on the boat then I would place wire thickness down the list of priorities. IMHO.

Now I understand the need for an MPPT or in my case even 2 as an MPPT is better than a PWM (Pulse Width Modulated) solar charge controller. However I have read that having a small power management such as MORNINGSTAR SUNKEEPER PANEL MOUNT CONTROLLER on each panel as well as an MPPT is the way to go.

Then you have the chargers, investors, fuses, breakers and there are even some interesting lightning protectors out there to add into the circuit.

Oh I forgot. Temperature sensors for the battery bank area and a high amp alternator/s for the engine. Along with an efficient generator hookup.

Now I have also learned that just about every battery monitoring component draws power. Causing a small loss over the network.

Also I know of some MPPT'S that can manage both solar, wind and water turbine. I'm not interested in the water turbine because of its effect on the hull speed.

Funny though that I'm worrying about the effect on hull speed by a water dynamo apparatus when I'm adding a ton of weight in solar panels.

Which brings me almost full circle in designing and understanding the system I'm planning. Is it wise to max out on heavy panels or should I go for the new lighter weight high wattage models. I will have much less weight and less wattage output.

Nothing in deciding how large your Lifepo4 system should be is simple.

For instance, like I asked earlier, is having a bank made up of 1,000AH batteries better than having more lower AMP batteries to make up the same stored AMP hours.

I will in all likelihood continue asking dumb questions. Yes I know it is probably annoying for all those who know everything already. I will continue researching the latest products and advances. And I will continue questioning thoughts and ideas by experts since I am already finding contradictions amongst the experts.

At the end of t he day I am going to probably hire a professional in the industry but it's not going to be pleasant. I am going to be armed with enough from my research to challenge every assumption until I'm satisfied I will have the best power generation system possible. Then let him go ahead and build it. I don't do wiring.

[transmitterdan]

Wiring panels in series increases voltage thus same size wire for more power. But shading of one panel reduces the current in all panels.

Wiring panels in parallel increases current thus needing bigger wire. Shading of one panel in parallel reduces current from that one panel but the others still produce full output.

There is no free lunch.

[exMaggieDrum]

This subject is more than a little intimidating. I laugh every time someone says to just read the entire thread and then it will all be clear to you. First of all, much of the stuff on this thread seems just plain wrong (by well-meaning posters), contradictory, and a mess organizationally. It goes back several years with many developments and experiences between the start of the thread and this last post. Over 5000 posts over several years!!

I dare anyone to read all this and remember the last 100 posts let alone all of them. I have made so many notes and summaries I forget where I put the last summary. And all the "competing" ideas and proclamations by sundry "experts". One of the first tasks is to feel out who the really knowledgeable people are on here and then pay more attention to them than to others.

Maine Sail is obviously one of the best gurus here, among others, and his blog at Compass Marine is the best overall summary I have seen. But it does not have everything to know in it and much of it is presented as opinion rather than fact. I take it as the best "fact" available first, then bounce other expert "facts" against it and try to decide which is most likely to be right.

In other words, the book is still being written about all this. The best I can recommend is to read the whole thing just so you can tell everyone you did, and take notes. Then you can take the 1000 pages of handwritten or computer notes you wrote and try to make some sense of them all. Then start putting it all together on paper in a real system asking yourself questions that you then try to find answers for in your notes. Then you find that your notes are questionable so you go back to the thread posts and find out they don't even address the question you have, or if they do, they only give some little clues to what the real question is let alone the real answer.

Some day, one of these guys will actually publish a more polished "how to" for all this. I suspect some have even started but found that their real jobs get in the way of this. And, that there are still a lot of nagging questions about fact and fiction. E.g. do you subscribe to the camp that says you need an elaborate BMS system to prevent severe over/under charging or is it OK to skip that and just set your charging and load systems in a simpler design relying more on manual observation? Do you go with expensive complete battery systems with built-in BMS? What are even the right parameters for charging and discharging? For which brands of cells?

What I see with all this is just an interesting path for a risk-taking, intellectually challenging, bank account draining exercise to DIY nirvana. I'm beginning to believe that it really isn't too bad but there are many gotchas waiting to kill your batteries in your home port or leave you stranded in foreign seas with no replacement cells available for weeks if not months out. I also am getting more and more confident that it is really not that bad but it hasn't been easy getting to this point.

On a good note, I got my 16 new Sinopoly 100Ah cells on Tuesday and started top balancing them yesterday with my new power supply. I already wish I had a power supply with better controls and adjustments but I may just need to figure out the tricks for what I have. My best Fluke DVM only has one decimal for volts but I have another brand (major industrial quality unit) that has two decimals. So now I have to decide whether I can trust it or should I get a more precise Fluke for hundreds of dollars more. Or does it even matter really all that much to get it that precise when some are reporting that drift doesn't seem to be much of an issue in practice.

But I have a plan and I'm putting together a system and will try and document the process and data points for my own peace of mind. I also have to fend off all the "experts" who tell me lithium batteries are a dangerous joke that makes no financial or practical sense at all and that I should just stick with proven FLAs that you can get cheap at discount stores around the world.

[evm1024]

You should pick up a copy of Nigel Calder's book Boatowners Mechanical and Electrical Manual It will help.

In electricity Current is the flow of electrons (e.g. the number of electrons that flow through a wire per second) and is measured in amps.

The "force" that each electron has is the voltage.

It is the current that sets the size of the wire (as was noted above).

Each battery cell has the ability to supply some number of electrons per second (current) and when you put the cells in series they each pass the same number of electrons per second and thus the current is the same for a series string as for each cell. Each cell has a specific voltage (3.2v for LiFePO4 plus or minus) and with them in series the voltages add together thus 4 cells in series have the same current at one cell but 4 times the voltage (4 * 3.2 = 12.8).

When you place the cells in parallel the voltage of the cells do not add and thus is the same as a single cell. But each of the parallel cells supplies some number of electrons per second and those are added together. Thus cells in parallel have a greater current than a single cell.

(this holds true for solar panels too)

Regarding the size of the cells - it has been noted in this thread and in others that larger cells do not handle the movement of a sailboat very well and may fail due to that movement. Internal strength of the cell. It has been noted that the recommended max size of a cell for marine applications was 200 AH. I have no idea how true this is but it does make some sense.

Also, the failure of a single 1000 AH cell in a bank of 4 really screws up your house bank and costs lots to replace. While a failure of 1 200AH cell in a 1000 AH bank (5p4s - 5 200 AH cells to equal 1000 AH, 4 sets of 5 of them in series to equal 12.8 volts) only reduces the total capacity of the bank by 20% (1/5) to 800 AH....


Food for thought.

Regards