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

[Wraith_Mac]

Originally Posted by careka

Li-Ion BMS - Li-Ion battery cells

List of ho makes Lifepo batts.

Thank you for posting this.
Cheers,
Mac

[steelwrk1]

Hello Mac and Bob,

Thank you for your replies.

I've decided to dedsign and build the mounting support system for the 7 panels I can fit.... the 39" X 59" are max physical size. As mentioned I will use the Kyocera KD215GX LFBS.

It might not be as attractive as it will be functional, mounting all 7, but I'll give it a try, finishing trims will be figured out next year, haul out +/- Nov 4.

At the 215 watts each that will give me a max of 1505 watts. Each panel puts out 26.6 volts and at this voltage 8.09 amps.

I will have to learn more ,but these specs quoted are for ideal conditions.

My panels will be flat mounted and I wonder if you design a system around the absolute maximum outputs or remove some of the quoted maximums for incorrect angle and real life sun availability?

I do understand to mount the MPPT controllers as close to the batteries as possible as the wiring out of the MPPT's has to be large.

If I follow your thinking you would bring the 26.6 volts as it is right from each solar panel and run all the smaller 14 wires to the MPPT controllers to some sort of buss bar then into the MPPT controllers and then in Parallel from the Mppt controllers , using a large sized cable, to my house battery ?

I do not have a clear understanding on the running in Series or Parallel or the sizing of the wires from the 3 aft at lower level solar panels that are +/- 35' away from the MPPT controllers, then the two aft at upper level and finally the two forward solar panels that are +/- 25 feet away from my Planned positioning of the MPPt controllers.

I am in the initial stage and need to get a better understanding of the above.

Any more comments/suggestions would be welcome.

Best Regards,
Pete

[Cotemar]

Originally Posted by careka

Li-Ion BMS - Li-Ion battery cells

List of ho makes Lifepo batts.

Can they be any good if ho is making these Lifepo Batteries.

[ebaugh]

Pete,

You really need a good solar guy....but I will throw in some observations.

According to the Morningstar website, a TriStar 60 can only handle up to 4 of those panels, so you will need 2 controllers. The 4 panels can be wired 4P for around 26V, 2P2S for 52V or 4S for 104V. Offhand, I would wire them 4S, using AWG10 from the solar panels to the controller. These wires need to be carefully protected when installed since they will see up to 144V with an open circuit.

The 3 other panels wired in series are 3/4 of the voltage and current. Then there are two runs of duplex wire from the panels to the controllers.

If you wired them in parallel, for 26V, the wire size would need to be several sizes larger. There may be an advantage to this, but none I know of.

Bob

[Lagoon4us]

We have four 275watt 36volt panels on a tilting frame, at anchor if i want best from the panels i must:-
1) Move the boom to stop shading.
2) Tilt the panel to accomodate a constantly moving platform due to wind and tide.

The attached photo's show the aluminium box that tightly contains my 4 x 400 amp cells which have and do work extremely well for this cruising year.

Cheers

[deckofficer]

That is a really clean install and those cells are impressive. Should meet all your needs for decades, good job.

[Lagoon4us]

Whooops i meant to say 3 panels!!!!! Was looking at the 4 cell pic whilst typing, stupid brain....cofeeeeEEEEE!

Thanks Bob, Coldar, another forum member, has used my drawings and rigged the same panels on his 440, today he is anchored 200 metres away here in Turkey and the sun has just started to pour in our allotted amps for the day

[Wraith_Mac]

Steelwrk1,
Is this the model you have?
2001 Bayliner 4788 Pilot House Motoryacht Power New and Used Boats for
Bearing in mind that both Bob Ebaugh and Lagoon4us have accurately highlighted issues for consideration I'll offer, hopefully, some food for thought.
Note: I do not disagree with either of them but am just trying to be more specific to your boat.
First the distances involved are similar to those in large RVs, through these blogs and links you can pick up a lot of very useful info.
Not all will apply to you as they use FLA batts after the controller, wiring etc. up until then should be relevant.
HandyBob's Blog « Making off grid RV electrical systems work
RV Electrical
There are plenty of wire/distance sizing docs on the web and great advice from the likes of Mainesail on how to connect it:
Compass Marine "How To" Articles Photo Gallery by Compass Marine at pbase.com
Musings With Maine Sail - SailboatOwners.com
There is a lot of other information there but well worth the searching.
As Bob E says you will need more then one controller but due to your proposed layout a different problem emerges other than simple 4 panel limit. You really have three banks of arrays.
As far as wiring in parallel or series to determine wire sizes I believe you are affected by the following problems:
The two panels forward will always be seeing different sun than the stern mounted. Not in itself a problem if they have their own controller.
That leaves the five stern panels, one too many according to Bob E's note on Morningstar MPPT 60, there are other controllers such as the Outback MPPT 80 and the Midnite Solar range that could handle the five but is it the best solution?
I have link to Midnite's page because from it you can access lots of info.
MidNite Solar Products.
What to do with the configuration of the five?
Wiring panels in series does indeed result in higher voltages and smaller wire, it also takes out a larger chunk of power if even minimal shading of a panel in the array occurs.
There is still a lot of arguing on the web about 'how much' but not about the basic truth that less power is lost wiring in parallel [both cases with MPPT].
A university with which I had, and my wife still has, an association has quite a lot to do with solar panel research and I have been lucky enough to have social contact with researchers there who explained that if shadowing is a problem then wiring in parallel is their much preferred option. Also to use panels of a greater voltage than the bank and MPPT.
I'll happily grant you this is anecdotal evidence at best [no links] but they convinced me and their research data is privileged [corporate funding].
Back to your five panels, the upper and lower panels will also see the sun at different angles so technically the best controlling solution is top three panels as one bank and bottom two panels as a separate bank.
ie One controller and larger wires per bank.
Larger wires can accept higher voltages should you change your setup to serial, smaller wires cannot revert to lower voltages. They would need redoing.
That is not to say you can't find a controller which will handle them all, in series or parallel and wire them as you choose and have some success just [IMO] the best theoretical arrangement.
You boat and your budget after all.
As Bob E says, you need good solar professional advice or an experienced marine electrician with that solar experience to sort out any queries you have and check out wiring etc.
It's not an insurmountable problem for a DIY but a good pro can actually save you time and money if you know what questions to ask and understand the answers.
Well, I hope that gives you some things to think about rather than clouding the issue,
Cheers,
Mac

[steelwrk1]

Hello and Thank you for your comments Mac ,

Originally Posted by Wraith_Mac

Steelwrk1,

Is this the model you have?

2001 Bayliner 4788 Pilot House Motoryacht Power New and Used Boats for

YES IT IS THE SAME BOAT

REVISION 1;
PLEASE SEE MY PHOTOS ( CLICK IMAGES AT LEFT BELOW THE # OF POSTS I HAVE MADE)I DO NOT KNOW HOW TO POST A PIC HERE



Bearing in mind that both Bob Ebaugh and Lagoon4us have accurately highlighted issues for consideration I'll offer, hopefully, some food for thought. TKS

Note: I do not disagree with either of them but am just trying to be more specific to your boat. UNDERSTOOD

First the distances involved are similar to those in large RVs, through these blogs and links you can pick up a lot of very useful info.

HAVE PREVIOUSLY READ FROM ONE END TO OTHER WILL READ AGAIN NOW THAT I AM BEGINNING TO UNDERSTAND MORE


Not all will apply to you as they use FLA batts after the controller, wiring etc. up until then should be relevant.
HandyBob's Blog « Making off grid RV electrical systems work
RV Electrical

There are plenty of wire/distance sizing docs on the web and great advice from the likes of Mainesail on how to connect it: TKS
Compass Marine "How To" Articles Photo Gallery by Compass Marine at pbase.com
Musings With Maine Sail - SailboatOwners.com

There is a lot of other information there but well worth the searching.

As Bob E says you will need more then one controller but due to your proposed layout a different problem emerges other than simple 4 panel limit. You really have three banks of arrays.

TKS ,UNDERSTAND.
MY PHYSICAL FORMAT WILL BE ONE SET OF 3 PANELS LOWER AFT ...AND... TWO SETS OF 2 PANELS OF UPPER FORWARD AND UPPER AFT.
PLEASE SEE ATTACHED PICTURE AND IMAGINE TWO SOLAR PANELS POSITIONED 59'' AHEAD OF THE RADAR ARCH, TWO PANELS POSITIONED 59'' AFT OF THE RADAR ARCH.....EACH PAIR AT THE SAME ELEVATION AS THE BOTTOM OF THE RADAR OR TOP OF THE RADAR ARCH...THEN 3 PANELS POSITIONED AT THE UPPER DECK LEVEL EXTENDING AFT 59'' OVER THE SWIM PLATFORM ON TOP OF THE DINGY LIFT



As far as wiring in parallel or series to determine wire sizes I believe you are affected by the following problems:

The two panels forward will always be seeing different sun than the stern mounted. Not in itself a problem if they have their own controller.
UNDERSTOOD

That leaves the five stern panels, one too many according to Bob E's note on Morningstar MPPT 60, there are other controllers such as the Outback MPPT 80 and the Midnite Solar range that could handle the five but is it the best solution?

I SPOKE TO AN APPLICATIONS ENGINEER AT MIDNIGHT SOLAR.(HE IS A SAILOR WITH SOLAR PANELS ON HIS BOAT ) AND AS YOU AND BOB EXPLAINED TWO MPPT CONTROLLERS ARE BEST ADVISED FOR ME...HE ADVISED TO WAIT FOR THIS NEW PRODUCT, IT WILL BE AVAILABLE IN WHITE AS WELL FOR THE MARINE MARKET....SOMEWHERE AROUND HALF OF THE COST OF THEIR BIG UNIT, MAKING IT THE SAME MONEY FOR TWO SMALL AS ONE LARGE.

'' MidNite Solar’s The KID MPPT Charge Controller 150V Input, 30+ Amp .....It’s exciting to know that the KID will be released the first quarter of 2014!!! "

http://www.midnitesolar.com/pdfs/spe...t_kid_back.pdf


OutputI have link to Midnite's page because from it you can access lots of info.
MidNite Solar Products.

What to do with the configuration of the five? REFER TO ABOVE PICTURE AND CLARIFICATION

Wiring panels in series does indeed result in higher voltages and smaller wire, it also takes out a larger chunk of power if even minimal shading of a panel in the array occurs. OK I GOT IT

There is still a lot of arguing on the web about 'how much' but not about the basic truth that less power is lost wiring in parallel [both cases with MPPT].

A university with which I had, and my wife still has, an association has quite a lot to do with solar panel research and I have been lucky enough to have social contact with researchers there who explained that if shadowing is a problem then wiring in parallel is their much preferred option. Also to use panels of a greater voltage than the bank and MPPT.

TO MAKE SURE I UNDERSTAND.. KEEPING IN MIND MY SOLAR PANELS SPECS , AND MY APPLICATION......IF YOU HAD THE ABILITY AND WIRE SIZE WAS NOT AN ISSUE YOU WOULD WIRE IN PARALLEL RIGHT BACK TO THE MPPT CONTROLLERS AS THERE WOULD BE LESS LOSS.

I'll happily grant you this is anecdotal evidence at best [no links] but they convinced me and their research data is privileged [corporate funding].

Back to your five panels, the upper and lower panels will also see the sun at different angles so technically the best controlling solution is top three panels as one bank and bottom two panels as a separate bank.
ie One controller and larger wires per bank.

WITH MY CLARIFICATION I THINK YOU WOULD NOW SAY 3 LOWER AS ONE BANK AND 4 UPPER AS ANOTHER ?

SEE ATTACHED PIC, I BELIEVE THE UPPER 4 PANELS WOULD SEE THE SAME SUN WITH THE EXCEPTION OF THE SHADING FROM THE RADAR AND RUNNING LIGHT AND THE SUN DIRECTION FOR THE FORWARD UPPER TWO AND THE AFT UPPER TWO.

Larger wires can accept higher voltages should you change your setup to serial, smaller wires cannot revert to lower voltages. They would need redoing.

That is not to say you can't find a controller which will handle them all, in series or parallel and wire them as you choose and have some success just [IMO] the best theoretical arrangement.

You boat and your budget after all. TWO MPPT CONTROLLERS ,IS THE WAY I WILL GO

As Bob E says, you need good solar professional advice or an experienced marine electrician with that solar experience to sort out any queries you have and check out wiring etc.
WILL DO ,GOOD ADVICE. FOR THE FINAL SET UP, JUST WANT TO BE AS INFORMED AS POSSIBLE WHEN I CHOOSE THE PERSON...NOT TOO MANY HERE USING SOLAR SET UPS ON BOATS...BEST I KNOW A LITTLE SO I CAN BETTER CHOOSE THE PROFESSIONAL

It's not an insurmountable problem for a DIY but a good pro can actually save you time and money if you know what questions to ask and understand the answers.

TKS AGAIN GOOD ADVICE, I WILL DO ALL THE GRUNT WORK AND MECHANICAL, BUT WILL HAVE A SOLAR PERSON DO THE FINAL DESIGN AND FUSING AND INITIAL PROGRAMING OF THE MPPT CONTROLLER.
Well, I hope that gives you some things to think about rather than clouding the issue,

YOU CERTAINLY HAVE, AND THANK YOU, BOB E AND LAGOON4US FOR YOUR TIME, YOUR COMMENTS AND YOUR OBSERVATIONS
Cheers,
Mac

Very best regards,
Pete,

[Maine Sail]

Looks like one of the largest aircraft battery suppliers Concord Battery (as in Lifeline sister/parent company) is moving into LiFePO4 for aircraft...

Concord Battery Lithium Aircraft Batteries

[Wraith_Mac]

Pete,

TO MAKE SURE I UNDERSTAND.. KEEPING IN MIND MY SOLAR PANELS SPECS , AND MY APPLICATION......IF YOU HAD THE ABILITY AND WIRE SIZE WAS NOT AN ISSUE YOU WOULD WIRE IN PARALLEL RIGHT BACK TO THE MPPT CONTROLLERS AS THERE WOULD BE LESS LOSS.


Yes, but mainly for flexibility WRT shading.
If I could I would also run one size larger wire than specified to limit voltage drop over such a large run.
I'm not sure if there is any electrical disadvantage to combining the panel's wires close to the panels [in a combiner box] and reducing the number of wires running to the controller but would look into that also.

WITH MY CLARIFICATION I THINK YOU WOULD NOW SAY 3 LOWER AS ONE BANK AND 4 UPPER AS ANOTHER ?

Yes

SEE ATTACHED PIC, I BELIEVE THE UPPER 4 PANELS WOULD SEE THE SAME SUN WITH THE EXCEPTION OF THE SHADING FROM THE RADAR AND RUNNING LIGHT AND THE SUN DIRECTION FOR THE FORWARD UPPER TWO AND THE AFT UPPER TWO.

Yes

What to do with the configuration of the five? LOL! Rhetorical question!

I WILL DO ALL THE GRUNT WORK AND MECHANICAL, BUT WILL HAVE A SOLAR PERSON DO THE FINAL DESIGN AND FUSING AND INITIAL PROGRAMING OF THE MPPT CONTROLLER.

Yes, the more you can do the better but a pro's eye should be time and net money saver.

All the best, you should reap a lot of power,
Cheers,
Mac

[Wraith_Mac]

Originally Posted by Maine Sail

Looks like one of the largest aircraft battery suppliers Concord Battery (as in Lifeline sister/parent company) is moving into LiFePO4 for aircraft...

Concord Battery Lithium Aircraft Batteries

Maine, you do realise that when a 'plane blows a tyre now it will be the batteries fault?
They don't mention that the cons they list are mostly the same for all batteries on aircraft and seem to be only justifying a premium pricing policy.

As far as inflammability goes, it may be chemically true but the visuals on utube with a cell seem to tell a different story.
ie. It's hard work to get it to burn.
I guess they'll have to charge more to protect against that, maybe they should read CF more?

All kidding and anti-litigation tactics aside, it's great news, the more mainstream companies the better IMO.

Thanks for posting the news.
Cheers,
Mac

[hellosailor]

Pete-
40 feet from the batteries means 80' round trip, and that's how you work voltage drop and cable size. I'd put the panels in series for higher voltage and lower cable loss. so you've got something like 88 volts from the rear, 66 from the three in front, cleanest solution is as Bob suggests two controllers, two separate systems.

So if I read you right, that's 88 volts @150 amps from the rear, 66 @ 150 from the front, and I'd use the same cable size to make life simpler.

88 volts at 150 amps at eighty feet of cable...the Blue Seas calculator says to run 4/0 AWG cable allowing for a 3% voltage loss and running all day, not crossing through engine spaces. You can find loss calculators and wire sizers online, the only real question is how big a loss are you willing to tolerate in the cable (3% is typical) and how much can you afford to spend on the cable. Well, but the time you hit 4/0 cable there's bulk and weight to consider as well.

And of course, the choice of fully tinned marine cable or cheaper copper, which I think most of us would call unsuitable since it can corrode if not fully tinned.

But that's a starting point that you can shop and budget around.

There's also a pricey option in the Solarstik, which allows you to mount two large panels outboard on a fully rotating mount. They're expensive, but it would cost as much or more to make them yourself. Having the option to angel your panels and track the sun can make a difference of about 10% more power every hour or two, because you'll lose 10% every time the sun shifts that far. There's a very long thread about these things, posted here I think 5 years ago.

And there are tools online that tell you how many hours of sunlight you can expect per day by latitude, in temperate places a full day of sunlight may average about five-six hours worth of "noon" full power.

Your mileage will of course vary, but that's some basics to start with.

[marujo.sortudo]

I'm thinking about making the plunge this winter or next to LiFePO4. My current system consists of two GPL-31T Concorde AGMs (105 Ah each.) Each battery is it's own "bank" and runs to a 1/2/Both switch. The switch basically lives in the "both" position (there is a separate starting battery and alternator.) Each battery lays on it's side, one below the port quarterberth and one below the starboard quarterberth (presumably so trim stays uneffected by them.) There is an analog volt meter that can test each battery independently and two analog ammeters that show amps in/out. These have been sufficent for me to monitor the batteries and keep them healthy probably 300-400 cycles. Of course, they only rarely get above 20% DOD which can't be good for them. The engine (a Westerbeke 33A) has two alternators, a 60A for the starting circuit, and a dual-output 100A Balmar with a Balmar ARS III regulator for the house bank. We have a partially implemented solar install using a Morningstar Sunsaver MPPT-15L. The solar can be ignored for now as I'm willing to figure it out later. There is also a shore charger (an older Newmar, IIRC, I'd have to go look and see what model it is.) I'm also not very worried about this as the boat basically lives either on a mooring or at anchor. I can live without a shore charger if it isn't compatible.

I'm considering changing soon because: 1. the batteries are tired, 2. the bank is undersized for our current power needs, 3. one of the ammeters is fried and the other is looking shaky, 4. upgrading before I figure out solar and wind seems easier/less expensive than the other way around. I want the new system to meet the following requirements: 1. double the usable cruising capacity (based on operating in the 50-80% DOD band on the AGMs,) 2. can be retrofitted with AGM/gels if the batteries fail and LiFePO4 batteries aren't available (just imagining battery failure somewhere remote. This needn't be an ideal battery pack/charging scenario, just a stop-gap.) 3. Optimized for life at anchor, shore charging will be very, very rare, 4. Keep the system as simple as possible.

As far as what I'm imagining for replacement, I don't see the need to keep the house batteries split into two "banks." I imagine that right now the batteries get slightly different charging/loads as the wire runs are significantly different in length. In fact, given the reduction in weight and volume available with a switch to lithium, I think I could just have the batteries on the starboard side where the wire runs would be very short. 4 180Ah lithium batteries (CALB?) would seem to fit the bill well and, by my calculation, roughly double the usable amp-hours in typical cruising use. Bottom balancing them, limiting charging them to 3.6V/cell, and doing periodic checks would seem good enough to maintain battery health without a BMS and keep things simple. I'm also thinking that rather than replacing the ammeters, now might be the time to add a battery monitor instead. Beyond that, it may be that I'd need/want a new regulator, and I definitely want some kind of low voltage cut-off to protect the batteries from bottoming out. I welcome your thoughts for what I've missed or what can be improved in this plan.

[steelwrk1]

Hello Mac,

Thanks for the suggestions and comments.

I will look into your questioning of "combiner boxes" as it has already been mentioned to me, I am beginning to understand it better so I will grasp it better next time around ;
I'm not sure if there is any electrical disadvantage to combining the panel's wires close to the panels [in a combiner box] and reducing the number of wires running to the controller but would look into that also.

The norm is you get what you pay for and a good Pro will save me money, I just want to have an overall concept in mind so when it is proposed I have a better understanding of it. I also need a better understanding of what is available, versus what may be proposed, as it is in stock

Tks again,
Pete