LiFePo4 for DUMMIES

[Caracal]

Originally Posted by sparrowhawk1

If you're talking about the editing sorry about that. If not. ?

No, he was talking about this post:

http://www.cruisersforum.com/forums/...ml#post1456703

[darylat8750]

In the thread
Life batteries discussion for those using them as house banks,
Post number 3214 Maine Sail gives a picture of his control box.

http://www.cruisersforum.com/forums/...ml#post1408018

If you read from there through at least post 3238 it should be pretty clear what is needed. If it isn't clear a lot more reading is probably in order.

Dimensions of the cells are available on the web sites of the folks selling them.

[sparrowhawk1]

Originally Posted by darylat8750

In the thread
Life batteries discussion for those using them as house banks,
Post number 3214 Maine Sail gives a picture of his control box.

If you read from there through at least post 3238 it should be pretty clear what is needed. If it isn't clear a lot more reading is probably in order.

Dimensions of the cells are available on the web sites of the folks selling them.

You definitely took better notes than me. Thanks looking into it.

[westwinds]

Eclectic D400
See graph at this web site. It appears the D400 wind turbine puts out about 5 amps or 60 watts at 13 knots, which is about the average wind speed for the Caribbean. This produces 120 amp-hours in a 24-hour period.

Output Guide for some points on the graph:
10 knots wind speed produces 40 watts
15 knots wind speed produces 120 watts
20 knots wind speed produces 190 watts
25 knots wind speed produces 280 watts
32 knots wind speed produces 400 watts

For the solar at 820 watts full power, this works out to an average of 5 hours per day full power because no power if produced at night and during much of the day the sun hits the panel at an angle so full power is not produced all the times. So we divide 820 watts by 12 volts to get 68 amps at full power, then we take 5/24 times 68 to get 14 amps average over 24 hours or 340 amp-hour for solar.

This gives 460 amp-hour in 24 hours or 5520 watt-hours in 24 hours for both solar and wind.

My guess is the gel-cell bank is not producing 1000 amp-hours because of age. At 12 volts, that should be 12000 watt-hours. Your Xantrex should be able to run 12 hours full output until it shuts down from low voltage. I do not know what the useable life span is for LiFePO4, but better than gel-cell I think. This could make the LiFePO4 cheaper for dollars per year useable life span.

If you are using the Seafrost DC 5000 DC5000, this requires 492 watts or 11,808 watt-hours if running all the time. Better have a compressor on the engine?

If you are using the twin plate BDxpx, BD Series the current is 8.5 amps at 12 volts. Another amp is needed for water-cooling of the condenser on the refrigeration system. This is 2736 watt-hour in 24 hours. If you want two of these, you need 5472 watt-hour. If your refrigerator runs full time, the solar and wind will just keep up with the power demands at 5520 watt-hour. I think you should stick with the refrigeration system size you now have, as you will need some reserve power when the sky is cloudy.

You also need 50 amp-hour for lights or 25 watt-hour average over 24 hours. If you cook for an hour at 1000 watts, that is 42 watt-hour spread over 24 hours.

[Highland Fling]

Originally Posted by deckofficer

David,

To address your increased galley loads, big amp draws don't phase these cells, they are just what you need for the induction cook tops. No alarms because almost nil voltage sag.

I'm with you as far as wanting a single series string instead of series/parallel bank, but with the size bank you want combined with a 10" height limitation, series/parallel might be the only option to maximize your battery space. You can't lay the cells flat, but can have them on their side. The 200 ahr cell here Lithium Prismatic Batteries has a height of 9.2". A 4S3P combo would give you 600 a-hr @ 13 volts and would offer more usable a-hr than your 1000 a-hr lead bank, plus of course all the other benefits of using LiFePO4 cells.

BTW, a good bang for the buck if you can accept a 10.7" height would be the 195 a-hr cells that they have on sale. (12) of these cells would give you 585 a-hr @ 13 volts, only weigh 156 lbs (big reduction in weight over your 1000 a-hr lead bank) and total cost for 12 cells $2160, also a reduction over your $4000 quote on the gel cells.
195Ah 3.2V Power HiPower LiPo Li-Ion EV Battery LiFePo4 Lithium Prismatic 195Ah Battery

Thanks Bob,

I totally appreciate that changing over to these batteries will remove that voltage sage that i get with my LA batteries. Amazingly replacing the duff engine start battery with another 4D and adding it to the house bank when we are cooking has improved things no end BUT long term LiFePo4 is undoubtdly the way we need to and i want to go. Thanks for your heads up on the 195AH cells.

[deckofficer]

Originally Posted by Highland Fling

Thanks Bob,

I totally appreciate that changing over to these batteries will remove that voltage sage that i get with my LA batteries. Amazingly replacing the duff engine start battery with another 4D and adding it to the house bank when we are cooking has improved things no end BUT long term LiFePo4 is undoubtdly the way we need to and i want to go. Thanks for your heads up on the 195AH cells.

David,

Can you fit 10.7" cells (plus terminal bolts) in you battery space? If they won't fit the 200 a-hr cells aren't that much more in cost.

(12) 200 a-hr is $2772, so about $600 more for a cell that fits standing upright and has 5 a-hr more per cell.

[folivier]

Maybe MaineSails list could be a sticky?
Lots of great info right there.

[Highland Fling]

Originally Posted by deckofficer

David,

Can you fit 10.7" cells (plus terminal bolts) in you battery space? If they won't fit the 200 a-hr cells aren't that much more in cost.

(12) 200 a-hr is $2772, so about $600 more for a cell that fits standing upright and has 5 a-hr more per cell.

OFF the BOAT ATM

BUT we have the round posts on our batteries AND have the round post to stud converter type battery connections with wing nuts these just graze the boards that make up the berth bottoms. When i get back to HF i will measure how much height i have exactly and post back, that maybe a day or two.

We have the SeaFrost BDXP system air cooled. BD Series

This morning after doing some electric cooking last night we woke up with 50AH consumed, by lunchtime the batteries were happy 13+ volts and the Victorn energy monitor saying 100% charged the present solar was putting out over 12 A and even with the SeaFrost kicking in every 30 minutes (we have the electronic control module) the Electronic Thermostat/Thermometer with Speed Control (ETTsc) we were still charging at 6 A.

Two panels are running on a Morningstar 15A Sunsaver MPPT controller
Morningstar Corporation » SunSaver MPPT

the other two on a 20A Sunsaver PWM controller.
Morningstar Corporation » SunSaver

All four panels are 'just' sat on top of the bimini with no ability to angle towards the sun

IF or WHEN we go to 6 x Kyocera 140W solar panels
Kyocera KD140GX-LFBS 140 Watt 12 Volt Solar Module
we will have serial pairs each pair on a Morningstar 15A MPPT controller.

[Highland Fling]

Originally Posted by Maine Sail

Most of this has been posted here at CF already... I know I have given specifics for setting up a Balmar regulator and solar settings. I suspect this thread is moving slow because many of us have typed this information many times already....

To my way of thinking people are all too often going about system design BACKWARDS.....

It should not be; "Well I already have X now how can I make that work with LiFePO4?" LiFePO4 should be the determining factor and then all products and parameters should be designed around that.

If you want LiFePO4, and don't want a huge hole where your wallet used to be, start from scratch and engineer forward....

IMHO the bare minimums would be:

*Individual cell level monitoring that can trigger LVC / HVC
*The ability and tools to top balance the pack unless you are an epowered-boat and want to bottom balance.
*Proper over-current protection.
*Safe charge voltages and products than can do this with the best accuracy possible
*No solar controllers with built in temp compensation
*No voltage regulators with built in battery temp compensation
*Load bus / charge bus
*Alarm points that warn before LVC/HVC
*Cell compression case
*Adequate coverage for battery terminals
*Accurate voltage sensing for alternator charging
*Ah counter
*Solid state relay to cut battery charger


Products I use:

Balmar MC-614 Regulator
Mark Grasser 160A Alternator
Junsi Cell Log 8S - Individual Cell Voltage Monitoring
HousePower BMS and Cell Boards (bank HVC/LVC protection)
Link-Pro Battery Monitor (Ah counting)
Rogue Solar Controller
Class T Fuse
Tyco EV200 LVC Contactor
70A DPDT relays for Balmar and Solar HVC
Piezzo Buzzer for Alarms
Mastech 3030EX Benchtop Power Supply (balancing/charging in the shop)
Mastech 3050EX Benchtop Power Supply (balancing/charging in the shop)
*Sterling ProCharge Ultra shore charger (using custom program)
*Sterling Battery Chemistry Module to charge start battery

Well all of that sounds lovely even if the last few sound like a bit of overkill for your average cruiser, so how about a block layout diagram and maybe some costings and a list of MUST HAVES and Nice to Haves.

Also most of us are doing an upgrade so i cant agree we are thinking 'backwards' I know what i have and i know what i want and I think that LiFePo4 seem to be the ideal battery system for what i want to do with my boat and my cruising. To paraphrase Donald Rumsfeld...with some poetic license I have some known knowns and many known unknowns and unknown unknowns All I want to do it NOT REINVENT THE WHEEL.

I want a battery system that wont sag (voltage) under heavy load

LiFePO4 seems to be the best answer at this point in time.

I understand i need to watch and control Low Voltage Conditions (LVC) and do the same for High Voltage Conditions (HVC)

I understand that i seems a good idea to start off with fully balanced cells though the need for that is not critical it is just sensible practice

I understand that my charging Alternator, Wind and Solar will need 'tweaking' to meet the needs of a LiFePo4 battery bank.

I am happy to occasionally look at my batteries BUT for sure I want this to be a NON critical task and not a heavily time consuming one. To that end i hope to spend all the time i need understanding and building MY LiFePo4 system and then be able to relax enjoy the benefits and enjoy my sailing and cruising and basically 'just ignore' my batteries like i do at the moment - they will work in the background meeting all my electrical needs without my constant intervention.

I think that explains what i am looking for in quite simple and easy to understand non confusing terms. I am sure there are others just like me with similar goals and ambitions with regards to these LiFePo4 batteries.

Sadly i don't have 24/7 WiFi access ATM so i will need to wait till i am next online to read more here.

Thanks to all in advance who can assist and add to my font of knowledge and help me build the system i want and need.

[sparrowhawk1]

Originally Posted by Highland Fling

Well all of that sounds lovely even if the last few sound like a bit of overkill for your average cruiser, so how about a block layout diagram and maybe some costings and a list of MUST HAVES and Nice to Haves.

Also most of us are doing an upgrade so i cant agree we are thinking 'backwards' I know what i have and i know what i want and I think that LiFePo4 seem to be the ideal battery system for what i want to do with my boat and my cruising. To paraphrase Donald Rumsfeld...with some poetic license I have some known knowns and many known unknowns and unknown unknowns All I want to do it NOT REINVENT THE WHEEL.

I want a battery system that wont sag (voltage) under heavy load

LiFePO4 seems to be the best answer at this point in time.

I understand i need to watch and control Low Voltage Conditions (LVC) and do the same for High Voltage Conditions (HVC)

I understand that i seems a good idea to start off with fully balanced cells though the need for that is not critical it is just sensible practice

I understand that my charging Alternator, Wind and Solar will need 'tweaking' to meet the needs of a LiFePo4 battery bank.

I am happy to occasionally look at my batteries BUT for sure I want this to be a NON critical task and not a heavily time consuming one. To that end i hope to spend all the time i need understanding and building MY LiFePo4 system and then be able to relax enjoy the benefits and enjoy my sailing and cruising and basically 'just ignore' my batteries like i do at the moment - they will work in the background meeting all my electrical needs without my constant intervention.

I think that explains what i am looking for in quite simple and easy to understand non confusing terms. I am sure there are others just like me with similar goals and ambitions with regards to these LiFePo4 batteries.

Sadly i don't have 24/7 WiFi access ATM so i will need to wait till i am next online to read more here.

Thanks to all in advance who can assist and add to my font of knowledge and help me build the system i want and need.

Could not have said it better. right now I just want to read about monitors and safety controllers. Started a new thread but I think the gurus are getting tired.

[deckofficer]

David,

I hope the real pros in this field (Maine Sail and T1 Terry) get back to you for your next time on line. All I can add is LiFePO4 cells as a house bank is THE best bang for the buck. My experience is a 0.06 per cell volt sag under a 0.41 C load on my small bank. If you go with a 600 a-hr bank that would mean a voltage sag for the bank (@ 50% DOD) from 13.06 volts to 12.75 volts pulling a load of 246 amps. Pretty robust, lead can't touch that.

I'm not using my cells as a house bank, not using a BMS and only monitor cell voltage, so unlike Maine Sail and T1 Terry, I have no experience making them foolproof as a housebank. They can tell you how to set up things so that you automatically stay well within the knees, thus giving great cycle life without your intervention. When set up properly, unlike lead, will require no time or effort from you for their lifetime.

[Maine Sail]

Guys,

You may not be getting the answers you want because some of us believe you either:

A) Do your homework, study, read the white papers, research the products, design your system, draw a wiring diagram/schematic and install it yourself with a far better understanding than if one of us holds your hand and does everything for you.

Personally I will not post wiring diagrams or get into the minutia because I believe there is a level of responsibility that goes along with a Li system design that needs to be done by you, and not by others. Perhaps someone will hand-hold to the minutia level for you, but it can't be me. I simply find that irresponsible when dealing with LiFePO4.

I will post guidelines & share knowledge, and answer specific questions but I will not build your system for you and give you a detailed shopping list with part numbers, schematics etc... Sorry...

Building this list and researching what you need will yield a FAR BETTER and FAR MORE KNOWLEDGEABLE owner than handing you a recipe with all the secret ingredients.

If you don't have the capability to do any of this then please use option B...

B) Buy a pre-made factory system from the likes of Genasun or Mastervolt.


I'm sorry but I simply can not, with a good conscience, hand out all the short cuts to LiFePO4 as I simply do not feel this is safe nor is it prudent....

I have shown at length how I charge my system, what voltages are used, why I do that etc.. Heck I even posted my Balmar reg settings which I really was hoping owners could figure out on their own from reading the tread. Other owners have done the same.

There is enough information in the original thread to figure out everything you need to do. I believe that thread, as well as MUCH more research, are the bare minimum 101 level courses.

Yes it is tough to wade through but there is great info in there that really should be read. I spent a full two years doing research before jumping in, but a lot of that thread was not there when I was doing mine, so it is far easier now. Every day I continue to learn, read and research Li. I also continue to experiment to give myself even more understanding of the behavior.

Just my .02 and I hope you can understand where I sit on this.......

[deckofficer]

Maine Sail, I do understand where you sit on this and I think all the tech discussions have scared potential users.

Someone like David that is on the verge of switching and has a record of getting 13 years of service from gels, is a perfect candidate for the upgrade. He knows already how to treat batteries.

To put things simply, because of voltages being so close to lead acid, LiFePO4 cells are almost (IMHO) a drop in replacement. Granted, due to charge acceptance, outputs of alternators might need to be rolled back so it doesn't go into thermal limiting which is a much greater reduction in output. Not abusing the cells by having each cell monitored with a LV alarm the a LV cut off isn't a big technical deal. The same employed for charging and your done.

With me not having experience with using these cells as house banks, am I looking at it too simplistically?

[deckofficer]

Ouch, don't want to hear this.

On a lighter note, I'm on cycle #235, bet I'm about to catch you.

Soon I'm going to be testing 160 w-hr per kg cells with really high C rates. Should be interesting, and much faster to cycle.

[Cotemar]

I can agree with Maine Sail's post # 32 as to the knowledge you need to make a boat with LifePO4 house bank work safely. He has posted tons of great information and pictures which has helped me understand these batteries much better than I did just a few years ago.

My only issue is that as a LifePO4 student, the training manual is written like my little sisters diary. It’s deep and all over the place at 3,547 posts to date.

A new CF member coming into the LifePO4 thread today is treated to data overload trying to get through that thread.

If it was in categories it would be just like a book with chapters starting with and index and vocabulary.

Then when one wants to build a LifePO4 house bank, they can just do their reading and follow the chapter they need when they need it.