Lithium Batteries (for the rest of us)

[ebaugh]

Originally Posted by T1 Terry

He has developed lithium sodium batteries

the man really understands what is going on inside these cells and what was going on inside all the various types of lithium batteries.

T1 Terry

That is interesting technology. But it's not going on anything marine under 100ft. It weighs about 10 times LFP for the same energy storage capacity, which makes it at least 2-3 times Pb. For land based off grid solar, it may be a winner, but not for portable applications.

[hellosailor]

"information like that is what is really needed, "
Right. And the way the battery suppliers have pretty much avoided, making that data available, or avoided the testing to get it, makes them all look bad. If I had a product and I knew it really worked, I'd ship one pallet to Sandia (National Labs) and another to a university and a third to Consumer Reports or Practical Sailor, and say "Here's the protocol, have a good time." It might take two years to run a thousand-cycle test with realistic parameters, but then I'd have one hell of a good sales tool available with their confirmation.

The cost of the batteries to do that is *nothing* compared to any other advertising or marketing expense. The fact that no one is doing this, only says they wouldn't be able to confirm their claims. (Or else they're too damned stupid to be in business next year.)

Lithium-sodium? That's a new one on me. I'd heard of sodium-air, and liquid sodium (side benefit, you can cook breakfast on it), but LiNa is a new one to me. Why am I sure that one is going to ship by HazMat? <G> His video makes it sound more like a "saltwater" electrolyte earth station battery, suitable only for a very different fixed-installation market.

[Hyprdrv]

I'd Like (and probably bunch of guys) for you Techies to go back and read the original post.

Quote:
LI (lithium) FE (iron) PO4 (phosphate)

The thread: Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks
has over 2500 posts

For those of us that need to replace our battery banks in the near future, these batteries seem like the way to go, it seems like we are right on the verge of creating practical guidelines of how to purchase and install this technology in our boats.

I am starting this thread with the hope that what you are discussing in the related 2500 posts can be summarized for the rest of us.

I am seeing that I can buy 100ah 3.2 volt cells for $130. each Sinopoly 100 Amp Hour Lithium Battery

For the purpose of this discussion, Lets say that I took four of these, hooked them together and installed them in place of my old battery bank. I am using typical charging systems for a boat designed to maintain a lead acid battery bank. Would it work? and what are the issues?

The more technical aspects of this subject could go in the other thread but could you guys keep us posted as to what the current consensus is regarding these installations and what the issues are?

I understand the basic advantages of these batteries, but would somebody please do a brief outline for us (without getting to technical, please)

If you need to debate the technical issues, it should be done on the other thread except for the basics of the disagreement so that we can keep this discussion shorter and more navigable (for the rest of us) (End of Quote)

No where in the past 400 posts has any conclusions been posted. Nothing for the "the rest of us" has been stated that tells us how to set up the LiFePo4 batteries as a house bank or (in my case) a propulsion bank. If anything this has probably turned off a bunch of people to the LI batteries because you guys have made it seem to far out there for us to install and use.
Now don't get us wrong. Some may love this stuff and I have scratched out a few things that I find interesting but the end result is I'm NOT going to use anything but LiFePo4's in my 144V bank and would REALLY like to know what the installation, charging, wiring, and parameters would be to do this.

The majority of Car DYI guys are using large format LiFePo4's cells to do their conversions. Yes they are trying to get 10C out of their packs and we are probably at around 1C. Even to run a boat at 7 knots I use around 60A at 144V. House banks will be in the 10A range with some at 15A. Not much strain on these batteries.
Correct me if I'm wrong:
1. LiFePo4 batteries need to be strapped together to minimize swelling.
2. In most cases at 12V pacs of 4 in series to create a 12V battery the Parallel to create your bank for the AH.
3. From what I've read Bottom Balance the bats before installation. Seems to be the way to go and could be a whole subject on its own.
4. In most cases smart chargers can be programed to charge the batteries per the parameters set by the manufacture.
5. In NO CASE do you want to Trickle charge the batteries.
6. Charge to 95% then SHUT THE CHARGER OFF. No gain (other than a few AH's) and a higher chance of over charging the pack which is the worst thing that you can do to the bats.
7. Discharge can occur to 95% however it has been shown that the batteries can be brought back from the dead if discharged all the way. (don't try it)
8. To regulate the Over charge/ Over discharge use a relay. Would like to see wiring diagram of this and further discussion)
9. My understanding is solar charging and Genset charging is controlled the same way as a charger would be used. (this is unique to a boat, the DIY guys don't have the room.) So again in this case how do you control the "axillary" charging using these sources, relays? I know that in most cases the Solar Controllers just shut off so this should be a non issue.
10. Some of you guys are stating that mini charge cycles decrease the life of the batteries rather than going from a full (95%) discharge to a full (95%) charge cycle. This is the first time I've ever heard of this. Some conclusions please. Again this is more of a boater thing than a car.
11. BMS (Battery MANAGEMENT System) Again you love them or hate them. In most cases, from what I've read, more fires have been started do to the Management systems then ever the batteries. Highly subjective and very controversial.
12. BMS (Battery MONITORING System) Required and just dumb if you don't have something or totally ignore looking at the batteries every once in a while.
I'm sure there are more questions us laymen would like to know.

I'm sure all of us appreciate the info that can be printed but try and think of this thread as a teacher/student thread, tell us what the answer is. If we want to get technical we can go to the 5000 thread and ask there. You guys can fight over the answer then print the conclusion here.

Steve in Solomons MD

[Lagoon4us]

Correct me if I'm wrong:
1. LiFePo4 batteries need to be strapped together to minimize swelling. YES
2. In most cases at 12V pacs of 4 in series to create a 12V battery the Parallel to create your bank for the AH.YES
3. From what I've read Bottom Balance the bats before installation. Seems to be the way to go and could be a whole subject on its own. ONLY IF CELLS ARE NOT EQUAL VOLTAGE WHEN PURCHASED
4. In most cases smart chargers can be programed to charge the batteries per the parameters set by the manufacture.WE ARE USING OUR STANDARD DOLPHIN CHARGER SET ON A USABLE CHARGE RATE
5. In NO CASE do you want to Trickle charge the batteries.OUR MPPT THATS BUILT FOR LITHIUM USES A 'MAINTENENCE VOLTAGE -GSL BRAND
6. Charge to 95% then SHUT THE CHARGER OFF. No gain (other than a few AH's) and a higher chance of over charging the pack which is the worst thing that you can do to the bats.I MONITOR USING A BEP MONITOR AND THIS SEEMS TO WORK OK
7. Discharge can occur to 95% however it has been shown that the batteries can be brought back from the dead if discharged all the way. (don't try it)WE DON'T DISCHARGE BELOW 25%
8. To regulate the Over charge/ Over discharge use a relay. Would like to see wiring diagram of this and further discussion)I HAVE A RELAY ON THE CONNECTION TO THE BATTERY PACK THAT I ACTUATE MANUALLY SHOULD A HIGH OR LOW VOLTAGE ALARM SOUND FROM THE MONITOR OR CELL LOGGER
9. My understanding is solar charging and Genset charging is controlled the same way as a charger would be used. (this is unique to a boat, the DIY guys don't have the room.) So again in this case how do you control the "axillary" charging using these sources, relays? I know that in most cases the Solar Controllers just shut off so this should be a non issue.CORRECT THE MPPT IF SET UP FOR LITHIUM WILL CONTROL OK THEN SIMPLY OBSERVE WHEN USING EITHER SHORE POWER CHARGER OR ALTERNATOR FROM ENGINE
10. Some of you guys are stating that mini charge cycles decrease the life of the batteries rather than going from a full (95%) discharge to a full (95%) charge cycle. This is the first time I've ever heard of this. Some conclusions please. Again this is more of a boater thing than a car.WE WORK IN 25% TO 90% LEAVE THE ARGUMENT TO THE KNOWLEDGEABLE ONES
11. BMS (Battery MANAGEMENT System) Again you love them or hate them. In most cases, from what I've read, more fires have been started do to the Management systems then ever the batteries. Highly subjective and very controversial. WE DONT HAVE AN AUTOMATIC BMS, I MONITOR THEM I DECIDE WHEN TO SHUT THE CHARGE DOWN
12. BMS (Battery MONITORING System) Required and just dumb if you don't have something or totally ignore looking at the batteries every once in a while.
I'm sure there are more questions us laymen would like to know.SEE ANSWER 11

My only experience with these cells is the pack i built some 7 or so months ago that powers our boats 'house' supply.

[T1 Terry]

Hi Steve,
If you want to use the cells as propulsion batteries, look at the EV forums, they are the information people regarding that type of use. Bottom balancing is an EV, thing, not a house battery thing, the idea with house batteries is to avoid hitting the bottom, the EV people often hit the bottom every cycle, a whole different world.
I can only repeat the same stuff so many times, if you haven't read it that many times you know it word for word it just means you haven't read it and are trying to understand the book by reading the last page. If you really want to know, read both the threads, you will pick up the theme fairly quickly and be able to pick out who is trying to swim against the current,, then check out why that might be, commercial interests or troll, but this only relates to house batteries, propulsion battery are a different ball game.

T1 Terry

[Hyprdrv]

Understood Terry and believe me I have read every post here and a lot else where on the subject. I've also read the DIY pages as well. Other than the Genset and Solar Cell issues for recharging the Car guys are where I get my Propulsion info from.
Don't get me wrong, I love the info and have learned a lot from you guys and we ALL are appreciative of the discussions, it's just at some point there has to be conclusions even if it's by vote. Some are simple to get to others are more complicated but there has to be conclusions and that was what this post was suppose to be about. The more people going to LiFePo4's the more suppliers and then the lower the cost for the cells will be. As I said the "other" string can be for the Tech side of an answer and if there is a disagreement on something we can be sent there for a more in depth discussion. Just because your a Techy doesn't mean you should ignore this thread but there has to be SOME points you all agree on!

Steve in Solomons MD

[Maine Sail]

Originally Posted by Hyprdrv

Understood Terry and believe me I have read every post here and a lot else where on the subject. I've also read the DIY pages as well. Other than the Genset and Solar Cell issues for recharging the Car guys are where I get my Propulsion info from.
Don't get me wrong, I love the info and have learned a lot from you guys and we ALL are appreciative of the discussions, it's just at some point there has to be conclusions even if it's by vote. Some are simple to get to others are more complicated but there has to be conclusions and that was what this post was suppose to be about. The more people going to LiFePo4's the more suppliers and then the lower the cost for the cells will be. As I said the "other" string can be for the Tech side of an answer and if there is a disagreement on something we can be sent there for a more in depth discussion. Just because your a Techy doesn't mean you should ignore this thread but there has to be SOME points you all agree on!

Steve in Solomons MD

Steve,

The problem is we all use these batteries differently. T1 and Lagoon are there to listen for alarms and can manually manage the system. Are you going to be there every time while your bank is charging? What if the dock power re-sets and boots your charger again? An audible alarm is no good if nobody is there to hear it so you may want to consider other safety measures..

You, and only you, can decide how you want to manage your bank but you really must study this on your own. I spent a full two years before jumping in. When I finally got the cells and began employing everything I learned on the web, I found lots of discrepancies so in reality had to re-educate myself and re-read everything I "thought" I knew.. There is no cook-book recipe as of yet.

For me I simply decided to stay out of the upper knee and never discharge below 80% but these are my own findings after hundreds of hours of testing & cycling our bank. The difference for me is that our bank is for my own education NOT just for our use. It is for experimenting, testing and trying to find a simple and safe way to use them, as a HOUSE bank. You are using them as a propulsion bank, quite different use...

The side benefit of our bank is we get to use it on our boat when she is in the water. When she comes out the bank goes back into the shop for more experimenting, cycling, internal resistance and capacity testing etc. etc..

Personally I cringe every time I hear of people pushing these cells to typical LA voltages but they seem to be comfortable with it. I just hope the cells survive it over the long haul. I also cringe when I see and hear of charger and controller manufacturers slapping a Li label on a piece of gear. Trust me the Sterling ProCharge Ultra/ProMariner ProNautic P LiDePO4 setting is NOT one would want to use, but it is still labeled as such.... Arghh...

Our battery management system is only there as an emergency back up, kind of like a bilge pump. It was very inexpensive to build. We also have a battery "monitoring" system....

We only currently charge to essentially 13.8V (well 13.9V for 30 minutes then to 13.8V until 5A accepted current at 13.8V then terminate.) so our BMS cell balancing, LVC, HVC & bank disconnect is never employed unless there were to be a mistake or failure of a component I was not there to catch.

I do not charge, to anywhere near full, unattended as for a house bank there is little need to do so.

I would suggest not just monitoring the new cells balance in a rested state but also measure them under load and during charging to make sure they are remaining balanced. Ours came out of the box at pretty much the same resting voltage but under load and charge they unbalanced slightly requiring a top balance. They are now closing in on 200 cycles and are in near perfect balance, still.

For your use a bottom balance would likely be better but I would personally never discharge to 95% and I would simply size the bank larger to compensate and discharge to only 80% DOD... Again, this is something YOU must decide....

Problem is, at this point, there is no consensus, thus no cook-book, so threads like this are just another avenue for your own education. 4 VPC on Winston cells for example will empty you wallet in no-time, but folks who've not done the testing themselves believe they can do that because the Chinese spec sheet says so....

Keep reading and keep learning it is all you can really do at this point.....

[Hyprdrv]

Thanks MS,
I agree 100% with what you're saying however there are still some very basic points that can be taken off the table as far as disagreeing. Those are the points that should be listed here. As an example I've seen many tests bringing the bats down to 0% charge and bringing them back with no damage. Personaly I will not discharge below 80% eather but then there may be an emergancy that would require me to go to 95% (or even till they are dead for that matter) but the point is on the bottom side they can be drawn down that far. However on the charging side there are MANY cases of damage do to Overcharging. Hense NEVER go to 100% charging, it's just not worth it. Then there is the matter of Trickle (float) charging where there is many a warning not to do it. Shut the charger off when at 90%/95% charge (or lower). Why can't these simple points be clearly stated and agreed apone?
We just need to clearify the installation and good Practice.
We need to have clear instructions to wiring and safety issues.
We need to understand the love and care of these batteries and how best to keep them healthy.
And No I'm not going to be there 100% of the time so need to have a safety system in place that shuts things off when the peramiters are exceeded. Both the Charging side and the Discharging side. That's why I'm more interested in relays to do this. BMS (management) systems that are out there are incorporating balancing as well as limits. Those I am leary of and think the simpler "shut me off captain" (smoc) approach is better. However that is MO and can be swayed in the other forum.
It would be great if the Tech Forum would addess an issue fully then draw a conclusion at the end of a subject and edit a list in 1 posting or in this string.
Again I don't want people to turn away from this form of energy storage simply becouse of "discussions" that are way to technical for the laymen.
Yes house banks are WAY simpler than a Propulsion bank and different but the basics are all the same.
Steve in Solomons MD

[hellosailor]

Steve-
"You guys can fight over the answer then print the conclusion here. "

As the folks who MAKE these batteries can't agree on most of the answers, what value can you put in any conclusion that the rest of us might draw?

The only way to get real results and answers, sadly, is to buy lots of batteries and "eat your own dogfood" as they say. Of course by the time you have cycle tested one set of batteries, it might be obsoleted by the next battery chemistry, making that a futile and expensive exercise.

[deckofficer]

Speaking as an EV guy, if you need a propulsion bank, these are your batteries. For a house bank they are a nice luxury due to minimal voltage sag under heavy load, nil Puekert, high charge acceptance, lighter weight, 2X usable a-hr, no corrosion, and more cycle life than you would need as a house bank.

[ebaugh]

In one of the threads I reported an estimated capacity loss of about 15% over a 1 year period of time on my LFP bank installed June 2012. I sent an email to a researcher studying capacity loss in LFP cells, and he responded with some data published in research papers. I am wading through it now, but for this thread...temperature and SOC matter. See the attached graph. If you operate the boat under power (I have too...no sails), and store your bank in the engine room, there is a big hit on life capacity. Further, if you have storage periods, don't leave them at 100%.

[T1 Terry]

Hmmm.... The problem seems to be, who do you believe:
The guy with the most runs on the board but not actually in a boat,
The guy with a lot of runs on the board in a boat but using a slightly different chemistry so the results and figures may be a little different
The guy who has based a lot of his knowledge on a different style of cell so some of his knowledge is in dispute
The other users who have results of their own
The guy who had a professorship award because of his knowledge in these batteries and is the person who sets up the stuff for NASA and the longest running house battery to date
The ones who don't actually have any of these batteries but seem to think they are a fount of knowledge

Or a combination of all this knowledge, weigh one finding against another, look for repeat results or patterns of results so the grain can be sorted from the chaff and build a system that suits your needs. Only you can decide the answer to these questions.

T1 Terry

[transmitterdan]

Originally Posted by ebaugh

In one of the threads I reported an estimated capacity loss of about 15% over a 1 year period of time on my LFP bank installed June 2012. I sent an email to a researcher studying capacity loss in LFP cells, and he responded with some data published in research papers. I am wading through it now, but for this thread...temperature and SOC matter. See the attached graph. If you operate the boat under power (I have too...no sails), and store your bank in the engine room, there is a big hit on life capacity. Further, if you have storage periods, don't leave them at 100%.

Thanks for the interesting numbers. I'm not sure I would say this argues strictly against storage at 100% charge. An expected lifetime of 10 years is probably "good enough" for many of us. The complexities of avoiding the 100% long term conditions are probably not worth the bother. If one adopts Maine Sail's approach and just limit to 90% or so then that should be ok.

The temperature degradation of life is expected but not very surprising. They appear to be worse than plain capacitors. For a 20C increase in temperature the lifetime looks to be cut by an order of magnitude. So for the typical cruiser at 30-35C the life is maybe cut in half. So the lifetime might be about the same as well maintained LA batteries. I think that's not a deal breaker though. Battery temperature monitoring looks to be warranted. Higher temps would indicate charging to less than 100% to preserve lifetime.

I suspect it would be possible to design a device that accepted charge inputs from multiple sources (charger, alternator, solar) and combine them to charge a LiFePo pack. This device could have the BMS (M stands for monitoring) built in. It could create a charge profile specifically for these new batteries. All that would be needed is for the charger and alternator to have a constant voltage mode with remote battery sensing. The device would send voltage back to each charge source that controlled the amount of current delivered by each source. If a source had its own current limiting that would be ok. It would be easy for the "Li combiner" to limit the current drawn by the bank from each charging source to avoid burning up conventional alternators.

Such a device would pretty much get what the OP wants. A system for "the rest of us" who just want to install it and not worry about it. I wonder if there is any real interest in this idea. I could be convinced to spend a little free time trying to come up with a specification and cost budget. Maybe could even build a few to see if the idea works. I see a market for some clever electrical supplier(s). Or maybe the open source route. If OCPN can do it why not OLiFePo?

[transmitterdan]

Originally Posted by T1 Terry

Hmmm.... The problem seems to be, who do you believe:
The guy with the most runs on the board but not actually in a boat,
The guy with a lot of runs on the board in a boat but using a slightly different chemistry so the results and figures may be a little different
The guy who has based a lot of his knowledge on a different style of cell so some of his knowledge is in dispute
The other users who have results of their own
The guy who had a professorship award because of his knowledge in these batteries and is the person who sets up the stuff for NASA and the longest running house battery to date
The ones who don't actually have any of these batteries but seem to think they are a fount of knowledge

Or a combination of all this knowledge, weigh one finding against another, look for repeat results or patterns of results so the grain can be sorted from the chaff and build a system that suits your needs. Only you can decide the answer to these questions.

T1 Terry

Terry,

Using a JPL or NASA person as a "guru" may or may not be helpful to the rest of us. JPL spent hundreds of millions on the two rover missions and even more on the Mars Science Lab mission. If something commercial were going to come out of that it would be on the market. JPL tests the bejeebers out of their batteries and selects the best possible ones from the best possible batch. They have to get good batteries. And they have years to test before the mission flies. Seldom does the success of a mission or subsystem solely rest on the shoulders of one person. Granted, after all that work and data collection the engineers will know a lot. But in my experience they often don't convert that knowledge into everyday applications at a price regular people are willing or even able to pay.

Right now it looks like temperature is the main detriment to lifetime. If you know something that says it isn't so please post some info. If temperature is the dominant factor in lifetime and it can be quantified and managed then all that is needed is a dedicated charge controller and SOC monitor with temp sensing.

But I don't see the value in personalizing what should be a purely technical issue illuminated by real data.

[ebaugh]

Temperature rise from charging is not my issue, I charge at C/8 or close. 140-160A on a 1200Ah bank. Ambient temperature is the concern, they live in the room with the mains and gensets. Up to 120F underway, and around 100F at anchor when charging.

The only temp rise I've ever seen at dock on charging is the heat dissipated by the balancers on the rare occasion I charge to 3.55V per cell. Those balancers are on the same PCB as the temp sensor....

Only semi intelligent speculation, but many, probably most trawlers have their banks in the engine room like I do, but probably far fewer on a percentage basis, sailboats since the engine room is...well the engine room without the space for a big house bank.