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12-18-2017, 08:40 PM
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#1
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Guru
City: Vermont
Join Date: Jan 2013
Posts: 10,097
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Lithium battery & component suggestions?
I am in the research and design stage of a lithium battery bank, and am looking for suggestions on battery manufacturers and BMS systems. This is for an off grid house, which is basically the same as a boat that's fast aground. Assuming success, I will then roll out a similar system on an actual floating boat.
The existing off grid battery system is flooded lead acid, 1300ah, 48V, so I get about 650ah of usable capacity, but it is reaching the end of it's life.
The lithium bank will be LiFePO4, and I'm targeting 300-600ah.
I have looked at a couple of the packaged systems like Victron and Mastervolt, but they are too much of a cost premium (3-4x) over buying cells, and a BMS, so I'm planning on the later.
My first question is about what battery manufacturers I should consider. I have looked at CALB and Winston so far, but am sure there are others. I want a vendor with some track record, or at least as much as anyone has in this field. Who else should I consider?
The second questions is about a BMS. I have seen arguments for varying levels of monitoring and active management. At a minimum, string voltage measurement with charge and load disconnect seems sensible.
Individual cell voltage monitoring would be taking the next step, and would detect cell imbalance that could cause a single cell to run too high or too low before the whole string voltage monitoring detects a problem.
Next would be automatic cell balancing. It's a nice feature, but many people argue that if you manually balance the cells initially and run the pack between 20% and 80% state of charge, then re-balancing is unnecessary. And if you are monitoring individual cells, at least you can detect when re-balancing is required and do it again manually.
And last is temp monitoring. I don't expect this will be much of an issue for the house where the battery location remains a constant 50-65 deg year round. But on a boat, higher temps are likely, and many LiFePO4 batteries have an operating temp of 40C or below.
So what recommendations do people have for a BMS?
OK, that should be enough to get the discussion started.
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12-18-2017, 08:51 PM
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#2
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Guru
City: Melbourne, FL
Join Date: Dec 2014
Posts: 1,731
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Have you looked at LG?
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12-18-2017, 09:01 PM
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#3
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Guru
City: Quebec
Vessel Name: Bleuvet
Vessel Model: Custom Built
Join Date: Jan 2016
Posts: 4,375
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12-18-2017, 09:11 PM
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#4
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Scraping Paint
City: CT
Join Date: Mar 2017
Posts: 963
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Here's my "boilerplate" LFP summary, mostly from Maine Sail (aka CMS here), please excuse any repetition wrt this thread
Any and all feedback is welcome!
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Bare cells: Winston/Voltronix, CALB, GBS, A123 & Sinopoly
Systems: OceanPlanet (Lithionics), Victron, MasterVolt, Redarc (Oz specific?)
Note nearly **every** vendor, also those of ancillary hardware touted as "LFP ready", gives charging voltages **way too high** for longevity.
My (conspiracy) theory is that manufacturers would prefer their cells get burned out in under 10 years.
EV usage is very different from much gentler House bank cycling. Most EV people talking "lithium-ion" mean other chemistries not as safe as LFP, much shorter lifetimes, and with completely different setpoints and behaviors.
My charge settings for LFP: 3.45Vpc which = 13.8V max for "12V".
Either stop when voltage is hit, or if you want another couple % SoC capacity, stop when tailing amps hits endAmps of .02C, or 2A per 100AH. Note even at the "low" max charge voltage, letting the charge source continue to "push" even low currents long past the endAmps point is **over-charging, and will** greatly reduce lifecycles.
If you can't then "just stop", set Float at 13.1V, but that is a compromise, and *may* shorten life cycles.
With LFP, you don't need to fill up all the way at all, as far as the cells are concerned, in fact it is bad for them to sit there more than a few minutes. Therefore only "fill up" if loads are present, ready to start discharging, ideally right away.
Store the bank as cool as possible and at 10-20% SoC, or maybe higher to compensate for self-discharge, if not getting topped up regularly (I would at least monthly). Letting the batts go "dead flat" = instant **permanent unrecoverable** damage.
Same with charging in below 32°F / 0°C freezing temps.
Persistent high temps also drastically shortens life.
Charging at 1C or even higher is no problem, as long as your wiring is that robust, vendors may spec lower out of legal caution.
Going above 14V won't add much AH capacity, but will shorten life cycles dramatically.
The point is to look at the SoC vs Voltage chart, and avoid the "shoulders" at both ends, stay in the smooth parts of the curve. And of course, we're talking about gentle "partial C" House bank discharge rates, size appropriately and be careful feeding heavy loads like a winch or windlass.
Following these tips, letting the BMS do active balancing is unnecessary and potentially harmful, just look for LVD / OVD and temp protection. Multiple layers of protection are advised if it is a very expensive bank, don't rely on any one device to work.
Check cell-level voltage balance say monthly to start, then quarterly, finally every six months if there are no imbalance issues, but only if that seems safe to you.
This thread is long but informative
http://www.cruisersforum.com/forums/...nks-65069.html
, make sure to give both Maine Sail and Ocean Planet your close attention.
Also MS' summary notes here
http://www.pbase.com/mainecruising/lifepo4_on_boats
**Everything** at that site is worth reading, very valuable. He also has great articles in Practical Sailor. His new site under development transitioning the pbase content is here
https://marinehowto.com/support, feel free to make a donation to help with those expenses.
Best of luck and do please report back here
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12-18-2017, 09:23 PM
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#5
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Guru
City: Vermont
Join Date: Jan 2013
Posts: 10,097
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Quote:
Originally Posted by stubones99
Have you looked at LG?
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Yes, a little bit. It appears that currently the only version they have available is the high voltage model which is around 400V. There is a 48V, but it doesn't appear to be available yet, and there is no installation manual or detailed info available.
The BMS is controlled via a CAN bus interface, so I would need to have detailed specs on that to interface to it. I don't know if these BMS interfaces are standardized, but my assumption is that they are not.
For the house system, my inverter company (Schneider electric Conext) actually has an interface box and is certified (or will be, supposedly) to work with the LG Resu 48V battery pack. So it is probably a viable route for that system.
However, it's not viable for the boat since it's 48V only. As a side subject, I have been considering a 48V inverter system, but that brings with it a whole host of other issues and is a subject for another thread. One of my big objectives is to use the house to prototype and and prove a system that can then be used on the boat. Going with the LG system would not accomplish that goal.
Bottom line, I think LG is out.
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12-18-2017, 09:27 PM
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#6
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Guru
City: Vermont
Join Date: Jan 2013
Posts: 10,097
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Quote:
Originally Posted by Lou_tribal
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God I hate all these new mobile-friendly web sites. Pretty pictures, scroll scroll scroll, and no Fu$@$)ing information.
Anyway, my recollection is that the Tesla Power wall is also a high voltage device, geared toward grid-tied solar system that operate in the 300-600V range.
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12-18-2017, 09:36 PM
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#7
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Guru
City: Melbourne, FL
Join Date: Dec 2014
Posts: 1,731
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If everything you read about Aquion Energy is true, they are coming back to life with a better battery in early 2018
According to their press releases, they provide better long life performance than just about all other technologies, as long as you don't charge or discharge them too fast, and don't let them freeze.
http://aquionenergy.com/company/overview/
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12-18-2017, 09:38 PM
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#8
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Guru
City: Vermont
Join Date: Jan 2013
Posts: 10,097
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Thanks. I've read CMS/MaineSail's stuff which is all very good. And I am working on the Magnum Opus over on Cruisers Forum, but not through it yet.
I was thinking of experimenting with using a PLC for a BMS. Most of the systems are from tiny companies and I don't want to get a dead end system. Cell and string voltage monitoring, temp monitoring, and disconnects should be pretty easy to control, I think. But I'm new to PLCs, so we will see.
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12-18-2017, 09:40 PM
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#9
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Guru
City: Quebec
Vessel Name: Bleuvet
Vessel Model: Custom Built
Join Date: Jan 2016
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Quote:
Originally Posted by twistedtree
God I hate all these new mobile-friendly web sites. Pretty pictures, scroll scroll scroll, and no Fu$@$)ing information.
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Come on Peter don't be such an old bloke
I agree these sites are just nice looking marketing display without much valuable info.
L
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12-18-2017, 09:41 PM
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#10
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Guru
City: Vermont
Join Date: Jan 2013
Posts: 10,097
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Quote:
Originally Posted by stubones99
If everything you read about Aquion Energy is true, they are coming back to life with a better battery in early 2018
According to their press releases, they provide better long life performance than just about all other technologies, as long as you don't charge or discharge them too fast, and don't let them freeze.
http://aquionenergy.com/company/overview/
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Excellent, and freshly out of Chapter 11 too. I'll pass.
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12-18-2017, 09:44 PM
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#12
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Guru
City: Vermont
Join Date: Jan 2013
Posts: 10,097
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Quote:
Originally Posted by Lou_tribal
Come on Peter don't be such an old bloke
I agree these sites are just nice looking marketing display without much valuable info.
L
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I'm one of the old guys from the Muppets. Either that or I'm Bunsen or Beaker.
Anyway, it's just frustrating when websites that used to contain good downloadable info have suddenly gone hollow. Try to find product info on Furuno's new web site. Very frustrating.
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12-18-2017, 09:48 PM
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#13
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Guru
City: Vermont
Join Date: Jan 2013
Posts: 10,097
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Quote:
Originally Posted by stubones99
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That's one I was looking at. Do you have any experience with them? They are much less expensive than some others, so if nothing else perhaps a good place to learn and get started. Then I see offerings from ABB, Siemens, Allen Bradley, Eaton, that are much more expensive, but that pretty much run the modern world.
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12-18-2017, 10:01 PM
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#15
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Guru
City: Melbourne, FL
Join Date: Dec 2014
Posts: 1,731
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I did a small control system with them a few years back. Nothing currently.
Nice thing was DIN rail mounting the whole system and then snap the modules you need together. Their coding system lets you test what you build, if my memory serves correctly.
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12-18-2017, 10:05 PM
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#16
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Scraping Paint
City: CT
Join Date: Mar 2017
Posts: 963
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How would these compare to using Arduino or RaspberryPi controllers?
I love the idea of DIY programming for non-essentials like monitoring, notification alarms, logging and reporting
but would really rather rely on known good robust KISS devices for the primary protection layers, ideally from mainstream players like Blue Sea, Victron, BEP, Marinco etc
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12-19-2017, 02:21 AM
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#17
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Guru
City: Pahrump, NV
Vessel Name: Pairadice
Vessel Model: Sold Selene 47
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Peter, PM sent hope it helps!
Cheers
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12-19-2017, 04:45 AM
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#18
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Guru
City: Looking
Vessel Name: --
Vessel Model: Between boats
Join Date: Aug 2017
Posts: 1,190
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Quote:
Originally Posted by stubones99
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I have used these at work for many projects. Very simple and versatile - Velocio.net
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12-19-2017, 05:12 AM
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#19
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Guru
City: Carefree, Arizona
Vessel Name: sunchaser V
Vessel Model: DeFever 48 (sold)
Join Date: Apr 2008
Posts: 10,188
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Peter
I can't top the suggestions you've received, but have a few questions on system design. First, how important is individual cell monitoring and are the manual rebalancing remedies simple or an aggravating requirement?
Second, would the land based charging systems be materially different than possible on the water thus affecting commonality in battery design and monitoring?
Third, is there sufficient user experience to suggest LFP batteries age gracefully and are longer lived than flooded cell?
Lastly, for existing flooded cell systems that are working successfully are existing chargers, inverters, combiners etc - usable in a switch to LFP?
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12-19-2017, 05:35 AM
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#20
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Guru
City: Vermont
Join Date: Jan 2013
Posts: 10,097
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Quote:
Originally Posted by john61ct
How would these compare to using Arduino or RaspberryPi controllers?
I love the idea of DIY programming for non-essentials like monitoring, notification alarms, logging and reporting
but would really rather rely on known good robust KISS devices for the primary protection layers, ideally from mainstream players like Blue Sea, Victron, BEP, Marinco etc
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I've been considering the Arduino/Pi angle as well. They strike me as more of a home-brew solution than using a PLC, but that might be an unfounded impression. I do expect it would be cheaper. What I do know is that I want something that in the end will be both rock solid reliability, and be maintainable into the future. I have a home monitoring system that I have been running for years, and it is completely un-maintainable now because of abandoned 3rd party products. I also just have to put up with the odd bug here and there in modules that vendors will never fix. So my thinking is that using a system that is built to run machinery day in and day out for a long, long time is a better fit. But I'm new to PLCs, so could be completely wrong.
When you refer to the primary protection layers, I assume you mean the BMS functions? The only thing I have seem from the mainstream players are combined battery+BMS that plug into their chargers/inverters. I am assuming that the control interface is proprietary with all of them, but don't know for sure. The easiest thing to do would be to buy into a packaged system. But they are significantly more expensive than an assembled system. Around 3x more expensive. If it was 50% more, or maybe even 2x I might do it. But right now it's still too much of a premium.
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