So my AGM's are a couple of years old now and I want to donate them to a community project in the area so I am thinking about taking the leap with Lithium so I can learn about the tech before selling systems for my customers. I would like to get about 6-8kWh useable out of them and we'll be giving offgrid living a shot. I have just started researching options. Our energy needs average 4-6kWh daily so pretty small system. I will use the grid as a backup and I also have my trusty Honda gennie just in case. I mostly install Midnite Solar and Outback product and don't plan on changing my system much except for adding some PV.
I would love your thoughts and advice for sourcing a DIY setup from the US.
cheers!
> I would love your thoughts and advice for sourcing a DIY setup from the US.
I would not do DIY Li battery setup. I don't have the patience to babysit them, and the few DIY BMS systems that exist, don't inspire me.
Doing some more research, it seems CALB cells are a fairly low cost way to go. I am not about to be making up hundreds of 186500 batteries even with a kit nor even striping down old laptop batteries and then building packs from the good cells and adding balancers and BMS etc etc. So I am already not DIY but don't want to pay the premium for a pretty box aka integrated solution.
So far Electriccarpartscompany.com seems to have good pricing on the cells. Not sure about the balancers or BMS. I am definitely looking for something reliable as I have to wait for weeks if not months to ship replacement parts down so I need a reliable BMS and a spare on hand.
Quote from: davidshelton on September 27, 2018, 12:43:25 PM
Doing some more research, it seems CALB cells are a fairly low cost way to go. I am not about to be making up hundreds of 186500 batteries even with a kit nor even striping down old laptop batteries and then building packs from the good cells and adding balancers and BMS etc etc. So I am already not DIY but don't want to pay the premium for a pretty box aka integrated solution.
So far Electriccarpartscompany.com seems to have good pricing on the cells. Not sure about the balancers or BMS. I am definitely looking for something reliable as I have to wait for weeks if not months to ship replacement parts down so I need a reliable BMS and a spare on hand.
Go to main page and do a search for lithium and or Calb batteries. There have been some detailed discussions in the past on using those and various charging schemes. I tried bottom balancing with no other protection and don't recommend that . It might work with some other safety measures. Seems like there have been various BMS solutions over the years so you will have to do some careful study to figure out what is available. Read up on the discussions and that will give you a lot of information .
There are ready made lithium packs with all the BMS built in available now too .
Larry
Quote from: ClassicCrazy on September 27, 2018, 06:42:59 PM
Seems like there have been various BMS solutions over the years so you will have to do some careful study
I've been using LFP for 4.5 years now and really happy with the entire setup.
Well before I even got the lithium, I built cell monitors that show me exactly what each cell in my battery is doing.
I consider "monitoring" perhaps the single most important thing you can do to any battery bank, not just lithium. Spot a developing problem early and fix it rather than have to deal with the consequences of a failure later.
With whatever form of cell balancing you choose to use (including none!), cell monitoring gives you the continuous confidence everything is ok.
I run all my loads through an inverter, so the LVD in the inverter is my "failsafe" against over-discharge.
Automatic generator start by the inverter, if battery volts or SoC ever get low (but still well before the LVD) means I've never got close to disconnect, and as such I consider a battery management system with LVD more of a liability than a benefit.
My charge sources all have a capped high voltage that is below the safe limit of the pack.
I have an alarm should voltages get close to that. It's only gone off once, and that was due to a deliberate act to test it.
I consider a battery management system with HVD more of a liability than a benefit too! (in my installation anyway)
I have 900AH @ 52V (around 40kWh of usable capacity) in my bank and am super happy with every aspect of them.
(I do have suitable HRC DC fuses in each bank as the ultimate disaster protection)
Check with mcgivor and Raj174 over at Northern Arizona Wind & Sun Solar Forum. I believe they are both doing something similar to what you are wanting.
http://forum.solar-electric.com/discussion/353773/instalation-up-and-running#latest
Quote from: RossW on September 27, 2018, 09:28:35 PM
Quote from: ClassicCrazy on September 27, 2018, 06:42:59 PM
Seems like there have been various BMS solutions over the years so you will have to do some careful study
I've been using LFP for 4.5 years now and really happy with the entire setup.
Well before I even got the lithium, I built cell monitors that show me exactly what each cell in my battery is doing.
I consider "monitoring" perhaps the single most important thing you can do to any battery bank, not just lithium. Spot a developing problem early and fix it rather than have to deal with the consequences of a failure later.
With whatever form of cell balancing you choose to use (including none!), cell monitoring gives you the continuous confidence everything is ok.
I run all my loads through an inverter, so the LVD in the inverter is my "failsafe" against over-discharge.
Automatic generator start by the inverter, if battery volts or SoC ever get low (but still well before the LVD) means I've never got close to disconnect, and as such I consider a battery management system with LVD more of a liability than a benefit.
My charge sources all have a capped high voltage that is below the safe limit of the pack.
I have an alarm should voltages get close to that. It's only gone off once, and that was due to a deliberate act to test it.
I consider a battery management system with HVD more of a liability than a benefit too! (in my installation anyway)
I have 900AH @ 52V (around 40kWh of usable capacity) in my bank and am super happy with every aspect of them.
(I do have suitable HRC DC fuses in each bank as the ultimate disaster protection)
Thanks for the detailed response! What was the SOC range you could play in without any individual cell reaching a critical low or high voltage? Did just using balancers keep the pack working together in harmony? Setting the LVD of the inverter within the bottom end of the operating voltage range good enough?
Depending on the day - we're a month into spring now, and if we've had a decent day previously, my banks are down to about 80% SoC at sunrise and back in float by around 10am. As the days get longer and the nights get shorter that gets even better.
A couple of overcast days sees the batteries getting down a bit. I had to start the generator the other day because I was going interstate for the day, batteries were down to 40% at 6am and I had doubts we'd get any useful sun - and I'd just made modifications to the generator on the weekend so wanted to be here when (if) it had to run. Ran the genset for an hour, brought the bank back up to 53% before I left. Of course we had enough sun then to have reached full charge during the day and I need not have bothered.
The inverter will autostart the genset at 30% SoC or 48V (3.0V per cell), both well within what I'd call "safe" limits. It's only done that a few times in the last 18 months, and has worked flawlessly.
I have simple balancers that maintain equal cell voltages all the time (not just "top-of-charge balancing"), and monitor their state to remain confident everything is doing as it should.
Quote from: RossW on October 06, 2018, 02:33:37 AM
....Ran the genset for an hour, brought the bank back up to 53% before I left. Of course we had enough sun then to have reached full charge during the day and I need not have bothered......
Wife calls the generator "Cloud Repeller" If not raining, clouds usually clear 20 minuets after starting it up !
Quote from: mike90045 on October 06, 2018, 02:33:16 PM
Quote from: RossW on October 06, 2018, 02:33:37 AM
....Ran the genset for an hour, brought the bank back up to 53% before I left. Of course we had enough sun then to have reached full charge during the day and I need not have bothered......
Wife calls the generator "Cloud Repeller" If not raining, clouds usually clear 20 minuets after starting it up !
Ha ha - yeah - often works that way doesn't it !
Larry
Quote from: RossW on September 27, 2018, 09:28:35 PM
Quote from: ClassicCrazy on September 27, 2018, 06:42:59 PM
Seems like there have been various BMS solutions over the years so you will have to do some careful study
I've been using LFP for 4.5 years now and really happy with the entire setup.
Well before I even got the lithium, I built cell monitors that show me exactly what each cell in my battery is doing.
I consider "monitoring" perhaps the single most important thing you can do to any battery bank, not just lithium. Spot a developing problem early and fix it rather than have to deal with the consequences of a failure later.
With whatever form of cell balancing you choose to use (including none!), cell monitoring gives you the continuous confidence everything is ok.
I run all my loads through an inverter, so the LVD in the inverter is my "failsafe" against over-discharge.
Automatic generator start by the inverter, if battery volts or SoC ever get low (but still well before the LVD) means I've never got close to disconnect, and as such I consider a battery management system with LVD more of a liability than a benefit.
My charge sources all have a capped high voltage that is below the safe limit of the pack.
I have an alarm should voltages get close to that. It's only gone off once, and that was due to a deliberate act to test it.
I consider a battery management system with HVD more of a liability than a benefit too! (in my installation anyway)
I have 900AH @ 52V (around 40kWh of usable capacity) in my bank and am super happy with every aspect of them.
(I do have suitable HRC DC fuses in each bank as the ultimate disaster protection)
Hey RossW wanted to thank you for the post - I am brand new to home solar - bought a cottage with an off grid Midnite system of 24V with a gen backup. Currently using LA but I have a 10 year old (1974) Dodge Dart which is powered by about a 30kw (50x180AH) lithium pack. I bottom balanced the cells a couple times and don't overcharge so never an issue. Have been thinking of replacing the lead acid with my lithium pack at cottage and going to ICE in the Dart. Seems the solar set up already has a charging high voltage cutoff and a low voltage GEN start point so not sure there is any real need for any other BMS system. I certainly have never needed it in my car. The cells can each be overcharged past 10v before there is an issue (now this from fooling around with individual cells) and on discharge they merely die if over discharged.
Any advice from someone actually using Li would be appreciated.
I would at least put some low voltage cutoff protection on your lithium . I tried bottom balancing some lifepo4 with no other protection. It was an experiment and to learn but I made some mistakes. Putting individual cell monitoring would be very decision - I probably would not have had the problems I had if I'd been doing that.
Larry
It seems to me that this whole Lithium Battery idea should be getting of age enough that there are some reputable commercial BMS systems to chose from. When will (or has any reputable company) started marketing a BMS or various BMS options so that one could skip the whole DIY route? I would not be confident making my own or contacting a Chinese manufacture to make one up to my specs, but I would have no problems following directions.
I also see Trojan has jumped into the market, but I have not heard much buzz about them.
There are lots of BMS these days on Aliexpress. Depends what voltage and current you need.
Here is one type
https://www.aliexpress.com/item/8S-24V-lifepo4-bms-waterproof-same-port-with-balance-18A-25A-35A-45A-60A-discharge-current/32873151474.html?spm=a2g0o.cart.99999999.259.49883c00oZk5OG
Or this one
https://www.aliexpress.com/item/8S-to-24S-Lifepo4-li-ion-Lithium-Battery-protection-70A-100A-150A-200A-300A-smart-bms/32962595842.html?spm=2114.search0604.3.29.1acf2612yAmLbn&ws_ab_test=searchweb0_0,searchweb201602_3_10065_10130_10068_10890_10547_319_10546_317_10548_10545_10696_453_10084_454_10083_10618_10307_537_536_10059_10884_10887_321_322_10103,searchweb201603_16,ppcSwitch_0&algo_expid=3eb8c1c3-71fd-42e0-adb6-af0d8d55833d-4&algo_pvid=3eb8c1c3-71fd-42e0-adb6-af0d8d55833d&transAbTest=ae803_5
Larry
But would those be considered Reliable and Safe over time. Especially if left unattended say at a cabin. Perhaps I am over thinking it and any simple BMS would pretty much suffice. I am not ready for Lithium just yet, but wanting to wrap my head around it because it seems some other chemistry besides LA is going to be in my future (probably in a lot of folks futures).
Could be you get what you pay for .
My suggestion with lithiums would be to experiment with a small pack and cheap bms to truly understand how they work and the ins and outs. You could make a pack out of used cells from recycled laptop battery packs or just buy some new 18650's . The radio controlled hobby sites sell small lithium packs too already put together but they rely on built in balance of external chargers .
Recommended book
https://www.amazon.com/DIY-Lithium-Batteries-Build-Battery/dp/0989906701
and this youtube channel
https://www.youtube.com/channel/UCRMrqzsrPIWvY3PINkLKs-Q
Larry
Calb is indeed the choice but there are other good brands check the guys at NAWS forum.
A BMS has it's advantages and disadvantages.
However, if you are thinking of getting one don't go cheap .
I have said it before if there would ever be a WBsr. Then that would be the answer .
Classics and kids already have all the features for lithium but it needs some hardware addition to corrolate with lithium for lvd hvd and soc
Orion BMS seems to be the choice for brands like iron edison and based on reviews they are good but you have to purchase a tool to verify connection of the battery to the BMS.This cost either the same or at least half the price of the BMS.
Anyone else have experience with the Orion BMS that mahendra mentions?
They are pricey, but seems like a sophisticated system with nice display and wifi monitoring add-ons. I'm still in the decision making process of proceeding without a BMS (carefully/conservatively programming the Classics to load/float and end-amps + monitoring w/ WBjr +BMK) vs. diving into the BMS realm. This is my first rodeo, so please share your considerations... mine is an off-grid diy application with Chevy Volt batteries.
bevans
Quote from: bevans on May 03, 2019, 03:35:02 PM
Anyone else have experience with the Orion BMS that mahendra mentions?
They are pricey, but seems like a sophisticated system with nice display and wifi monitoring add-ons. I'm still in the decision making process of proceeding without a BMS (carefully/conservatively programming the Classics to load/float and end-amps + monitoring w/ WBjr +BMK) vs. diving into the BMS realm. This is my first rodeo, so please share your considerations... mine is an off-grid diy application with Chevy Volt batteries.
bevans
This kinda seems like a read worth reading.
https://marinehowto.com/lifepo4-batteries-on-boats/
And here MIGHT be some other options for bms systems:
https://www.batteryspace.com/bms-master-module-for-lifepo4-battery-pack.aspx?gclid=Cj0KCQjwh6XmBRDRARIsAKNInDG-s5rXpR9v135ewGs6Yrol1mux9UCDe3Nkcnfr0FjQPlwp-UpuDM8aAmfKEALw_wcB
https://www.ev-power.eu/_d4493.html
Thank you, Matrix.
I like the tone of the Marine article. I'll look these over... nice build, btw.
In the meantime, please keep the lithium suggestions, perspectives and resources coming. I'm in the bulking phase of research.
bevans
BMS offers individual cell monitoring which is a good thing
Well, I decided to hold off on Lithium for a bit as my AGMs were still going strong but now I want to use them for small single module plus battery systems for a local community. So Lithium is back on the radar!
Seems like single cell balancers like the ones RossW uses should keep all the cells in harmony and setting inverter LBCO and charge set points diligently should be the K.I.S.S. approach to go with. That and monitoring with OpticsRE should be more than enough to ensure no under/over voltage of any cells, no?
I'm looking at the Fortune 100Ah cells which claim better lifecycle than the CALB cells.
Thoughts?
Can anyone recommend a source of these cells closer to Florida than Utah?
I don't know if it entered into your thinking but EV Batteries from Volts, Bolts, Nissans etc are now in the recycle chain and many are being upcycled for RE Storage. As such BMS solutions and harnesses have been appearing. I have a healthy FLA bank at this time but always thinking ahead and watching things unfold and if I'm still kickin when I have to change my batteries, upcycled EV batteries it will be, unless something better & cheaper pops up in the meantime ;-) .
Some links which may be of interest.
http://www.rec-bms.com/index.html <BMS systems +
https://www.youtube.com/user/devildestiny555/videos
This fellow recycles, upcycles EV Batteries & more - some Great Stuff and a wealth of info.
Quote from: Steve_S on June 30, 2019, 11:35:01 AM
I don't know if it entered into your thinking but EV Batteries from Volts, Bolts, Nissans etc are now in the recycle chain and many are being upcycled for RE Storage. ..........
And this is where the poop hits the blower.
The automotive batteries getting "up-cycled" likely have 2% of the cells going bad, pulling the rest of the pack down. They either have to be broken up and the used cells tested and re-binned according to capacity, or they are just selling sub groups that seem to pass whatever test "they" do.
So your upcycled cells are heavily used and being placed into lighter duty usage. If well binned, you might get a couple 2 or 3 more years of gentle use, but I would not count on them being reliable enough to run my off-grid house, or worth my maintenance bother and accelerated replacement intervals.
There are DIY possibilities and like anything else, it can be done properly or not. There are some businesses doing such which include thorough testing and certifying them as well. In Europe, there is already a respectable marketplace with upcycled EV batteries being used and sold for that purpose, as well as being repurposed into EV charging stations. Renault is doing this and even Tesla is doing so, to only mention two obvious ones.
We have a small company in this area refurbing EV batteries, complete with cell testing and verifications. You also get the correct harnesses and BMS which are reasonably priced and I have not heard a complaint since they been in business (5 yrs) and shipping across Canada. They're also swamped with orders and can't keep up with supply constraints being a problem. The failure rates of cells they've come to realize is actually quite low but there are some problems with early generation cells from Prius and one other I can't think of right now.
It is tempting to go with a CALB cell or Fortune Aluminium encased setup but I think I'll wait until the market develops a bit more. The fact that I install Outback systems makes me a bit more reluctant as I get installer pricing on those and not on any lithium option.
Here is something I built with the Fortune cells :
https://diysolarforum.com/threads/48v-lifepo4-build.6011/
Still working fine.