what about lithium ?

Discussion about the FM100, FM80, and FM60 Charge Controllers

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what about lithium ?

Post by lonewolf » Thu Dec 04, 2014 5:35 pm

Given that LiFePO4 (LFP) cells now out-perform PbA's by at least 200% in terns of total lifetime stored energy cost, I'm seriously wanting to replacing my leaden 20th century has-beens with safer, longer lasting, and enviro-friendly tech. BUT BUT BUT, apparently no manufacture yet produces CC's compatible with charging LFP's from RE sources. WTF? OR do 'they' (Outback)? Can my FM80's be configured (programmed) to behave appropriate to LFP requirements? Anyway, IMO the first company to get serious about RE charging for LFP cells will reap the bulk of said rewards.

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Re: what about lithium ?

Post by NFG » Fri Dec 05, 2014 12:44 am

Agreed,

There must be someone somewhere soon, would also be interesting if Vanadium batteries became an option for backup but think its a few years away.

N

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Re: what about lithium ?

Post by Gordon-Loomberah » Fri Dec 05, 2014 6:06 pm

lonewolf wrote:BUT, apparently no manufacture yet produces CC's compatible with charging LFP's from RE sources. WTF?
WTF indeed! That's nonsense...

I've had a set of CALB LiFePO4s running 2 for years, being charged with FM80s. A number of other companies sell LiFePO4s in a box with inbuilt charger and inverters etc.
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Re: what about lithium ?

Post by J » Wed Mar 04, 2015 10:20 am

I concur: the statement that a FLEXmax controller can't handle a lithium ion battery is nonsense! I have a newly installed system backed by 8kWhrs of lithium ion batteries (not quite LiFePO4) made by Enerdel. The charge regimen for lithium, on the whole, is simpler than lead-acid. With lithium ion you just set all charge phase voltages the same: absorb == float and NEVER equalize.

The caveat here is that lithium batteries need a battery management system (BMS), separate from the charge controller. The BMS is integrated into the battery pack, allowing it to monitor and control the voltages of each cell. It takes care of many of the strict requirements to which you may have been referring. The BMS is also what makes a separate periodic equalization charge unnecessary; the BMS handles that continuously.

With the BMS thus integrated and the charge controller voltages set appropriately, the system works great.

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Re: what about lithium ?

Post by blackswan555 » Wed Mar 04, 2015 10:27 am

Just out of interest, Price comparison AH vs AH?, Expected cycle life ? etc

Tim
My comments are based on my experience and research, They are not endorsed or checked by Outback.I am an independent British electrician living in Spain, So please take this into account when reading /acting on my post`s.

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Re: what about lithium ?

Post by Gordon-Loomberah » Wed Mar 04, 2015 1:58 pm

Information about cycle life at low DODs aty low discharge rates (not 1C or higher) for LiFePO4 is a bit hard to come by, but CALB say 2000 cycles to 80%DOD and 3000 cycles to 70%DOD for my 2012 cells, so at my typical 25-30% daily cycling DOD, I'm expecting they should last at least 4000-5000 cycles. I'm seeing a touch over 99% operating efficiency from them with my current charging regime, meaning much more energy is available from a given sized PV array in comparison with Pb-acid. I haven't had to run a generator since I installed the LiFePO4s.
Price wise, it depends on what you want to compare them with! I did a comparison with Raylites a while back, and for the same usable capacity LiFePO4 worked out to be less expensive.
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Re: what about lithium ?

Post by Wanbli » Mon Apr 30, 2018 6:32 am

J wrote:I concur: the statement that a FLEXmax controller can't handle a lithium ion battery is nonsense! I have a newly installed system backed by 8kWhrs of lithium ion batteries (not quite LiFePO4) made by Enerdel. The charge regimen for lithium, on the whole, is simpler than lead-acid. With lithium ion you just set all charge phase voltages the same: absorb == float and NEVER equalize.

The caveat here is that lithium batteries need a battery management system (BMS), separate from the charge controller. The BMS is integrated into the battery pack, allowing it to monitor and control the voltages of each cell. It takes care of many of the strict requirements to which you may have been referring. The BMS is also what makes a separate periodic equalization charge unnecessary; the BMS handles that continuously.

With the BMS thus integrated and the charge controller voltages set appropriately, the system works great.
I'm replacing my 12 years old Enersys PowerSafe DDM with 2 Tesla 5.3kwh battery modules @ 24vdc.Im trying to figure out how to integrate the Orion Jr BMS with the FM80 & FX3524'S. Has anyone had any experience with this? The Tesla modules have a built-in BMS, but I believe it's proprietary so not usable. Also, I tried to adjust the FX3524's to Max of 25vdc, but it's lowest setting is 26vdc, any way to overcome this as it will overcharge the battery?
Any help would be appreciated

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Re: what about lithium ?

Post by gtarolli » Mon Apr 30, 2018 9:25 am

Simpliphi makes LiFp batteries and have an application note for Outback chargers. I have 5 batteries and love them. At first I thought they were expensive due to being zero maintenance which I was willing to pay for. But if they really last 10000+ cycles they will end up being cheaper than other types. On good days we go down to 50%, on stormy days we go to 80% or 90% DOD.

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Re: what about lithium ?

Post by Wanbli » Mon Apr 30, 2018 10:15 am

gtarolli wrote:Simpliphi makes LiFp batteries and have an application note for Outback chargers. I have 5 batteries and love them. At first I thought they were expensive due to being zero maintenance which I was willing to pay for. But if they really last 10000+ cycles they will end up being cheaper than other types. On good days we go down to 50%, on stormy days we go to 80% or 90% DOD.
I appreciate the input, but I've already purchased my batteries, but I need to know how to setup the FM80 and FX3524 to charge them properly and keep them from being overcharged. If you can share how you setup yours, that would be great! Here's what I know so far:
Max Voltage: 25.2
Nominal Voltage: 22.2
Minimum Voltage: 18

One of my problems is the FX3524 has a minimum float voltage of 26v, that will over charge my batteries. So, I'm not sure how to setup this system's charge cycles.

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Re: what about lithium ?

Post by raysun » Mon Apr 30, 2018 12:29 pm

Wanbli wrote:
I appreciate the input, but I've already purchased my batteries, but I need to know how to setup the FM80 and FX3524 to charge them properly and keep them from being overcharged. If you can share how you setup yours, that would be great! Here's what I know so far:
Max Voltage: 25.2
Nominal Voltage: 22.2
Minimum Voltage: 18

One of my problems is the FX3524 has a minimum float voltage of 26v, that will over charge my batteries. So, I'm not sure how to setup this system's charge cycles.
Lithium batteries are usually charged in a two-stage process: constant current ("bulk"), followed by constant voltage ("absorb"). Once the battery has achieved its maximum desired charge, charging is cut off. Float charging is generally not employed.

The lithium battery management system (Orion Jr in this case) has provisions for low and high voltage battery cutout that should be used to protect the battery.

I'm not sure of the behavior, but setting the inverter and charge controller Float Time to zero may help to keep the high voltage cutoff from triggering for an excessive length of time.

Also, most lithium batteries have a charging terminals and separate discharge terminals. This is in marked contrast to lead acid batteries, which charge and discharge though the same terminals. The "lead acid replacement" batteries have an integrated BMS that "current steers" to/from the proper terminals.

It will be no problem for a charge controller to be attached to the charging terminals, but becomes somewhat more tricky for the inverter charger.

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Re: what about lithium ?

Post by gtarolli » Mon Apr 30, 2018 1:23 pm

I stick pretty close to the Simpliphi recommendations for 80% DOD, attached are images of my setup. Note there is no EQ, minimal absorb time, and then float until the sun goes down. I do not charge from the grid (we are off grid), and I only use the genset when I go below 20% which is after a day or two of rain. So the vast majority of the charging is done via solar and the PV charge controller. These batteries are 48v and designed to be drop-in replacements for lead-acid strings, i.e. their charging params are usually within what solar charge controllers can deal with. So that makes it easier, but probably not applicable to your batteries. Ideally you can get a good recommendation from the manufacturer.

The only thing outside the range is LBCO, which they recommend at 50v but I can only go as high as 48v (unless I upgrade my radian firmware which then means I need to upgrade my Mate3 to a Mate3s ...). I have only gone below 50v for a few hours this year so far, so I am not concerned.
image1.JPG
image2.JPG

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Re: what about lithium ?

Post by Wanbli » Mon Apr 30, 2018 1:26 pm

Thanks for the tip on setting the float to "0", that will help, can that also be done for the FX3524?
These Tesla battery module only have one set of terminals, it does have a builtin BMS, however it doesn't function without the main controller. I purchased an Orion Jr BMS, but I don't know how it integrates into the FM80/FX3524. Looking at how the module is wired, I see how it monitors each string, but can't imagine how it controls energy flow to one string over another over those very small wires. https://mega.nz/#F!9AFgyJJA!alhMF_YjYZRAKvBwok28SQ

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Re: what about lithium ?

Post by Wanbli » Mon Apr 30, 2018 1:40 pm

gtarolli wrote:I stick pretty close to the Simpliphi recommendations for 80% DOD, attached are images of my setup. Note there is no EQ, minimal absorb time, and then float until the sun goes down. I do not charge from the grid (we are off grid), and I only use the genset when I go below 20% which is after a day or two of rain. So the vast majority of the charging is done via solar and the PV charge controller. These batteries are 48v and designed to be drop-in replacements for lead-acid strings, i.e. their charging params are usually within what solar charge controllers can deal with. So that makes it easier, but probably not applicable to your batteries. Ideally you can get a good recommendation from the manufacturer.

The only thing outside the range is LBCO, which they recommend at 50v but I can only go as high as 48v (unless I upgrade my radian firmware which then means I need to upgrade my Mate3 to a Mate3s ...). I have only gone below 50v for a few hours this year so far, so I am not concerned.
image1.JPG
image2.JPG
Thanks, that was indeed helpful. The charge parameters of my batteries are different then yours though, so I'll have to experiment a little to fine tune them. A little scary considering what these things cost me! 8-[ I can't really go to the manufacturer since I got these from a wrecked Tesla Model S 85.

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Re: what about lithium ?

Post by raysun » Mon Apr 30, 2018 2:06 pm

Gordon-Loomberah wrote:Information about cycle life at low DODs aty low discharge rates (not 1C or higher) for LiFePO4 is a bit hard to come by, but CALB say 2000 cycles to 80%DOD and 3000 cycles to 70%DOD for my 2012 cells, so at my typical 25-30% daily cycling DOD, I'm expecting they should last at least 4000-5000 cycles. I'm seeing a touch over 99% operating efficiency from them with my current charging regime, meaning much more energy is available from a given sized PV array in comparison with Pb-acid. I haven't had to run a generator since I installed the LiFePO4s.
Price wise, it depends on what you want to compare them with! I did a comparison with Raylites a while back, and for the same usable capacity LiFePO4 worked out to be less expensive.
Which Calb cells are you using? What's the voltage and amp-hour capacity of your battery? What BMS do you use? How are you charging the pack?

Enquiring minds want to know. ;)
Last edited by raysun on Mon Apr 30, 2018 2:20 pm, edited 1 time in total.

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Re: what about lithium ?

Post by gtarolli » Mon Apr 30, 2018 2:19 pm

Someone else is using car batteries, I think Chevy Volt - do a search and see if you can find the posts. I think the big issue is they probably don't have built in BMS like someone mentioned and that might make them tricky to use.

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Re: what about lithium ?

Post by timmartin » Mon Apr 30, 2018 3:07 pm

raysun wrote: Which Calb cells are you using? What's the voltage and amp-hour capacity of your battery? What BMS do you use? How are you charging the pack?
Enquiring minds want to know. ;)
Don't know about him, but I am using CALB CA400 LiFePO4 3.2V batteries. They are connected in pairs to get 800Ah, then those pairs are in series to make a single string of 51.2 volts. I use a local-made BMS called "Atlas BMS", charging just like I did lead-acid, with outback charge controllers and a generator through FX inverter/chargers. The set points are all different of course... but I've made it work with the help of a trusted local installer who tried it first for himself.

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Re: what about lithium ?

Post by raysun » Mon Apr 30, 2018 3:28 pm

timmartin wrote:
raysun wrote: Which Calb cells are you using? What's the voltage and amp-hour capacity of your battery? What BMS do you use? How are you charging the pack?
Enquiring minds want to know. ;)
Don't know about him, but I am using CALB CA400 LiFePO4 3.2V batteries. They are connected in pairs to get 800Ah, then those pairs are in series to make a single string of 51.2 volts. I use a local-made BMS called "Atlas BMS", charging just like I did lead-acid, with outback charge controllers and a generator through FX inverter/chargers. The set points are all different of course... but I've made it work with the help of a trusted local installer who tried it first for himself.
Nice! I'm looking into doing something similar. Thanks.

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Re: what about lithium ?

Post by Gordon-Loomberah » Mon Apr 30, 2018 4:15 pm

raysun wrote: Which Calb cells are you using? What's the voltage and amp-hour capacity of your battery? What BMS do you use? How are you charging the pack?
I have 400AH CALB, the older blue cells, they've been in use for over 5 years now. I call the nominal cell voltage 3.3V, as my long term battery voltage average is very close to 53V (52.91V over the past 30 days). One cell had reduced capacity a couple of years ago, so I have replaced it with a Winston 400AH cell.

Since I reconfigured the cells from 8S2P to 16S nearly 4 years ago, I haven't been using a BMS. I Absorb for about 3 hours at 55.2V and float at 53.5V. At that float voltage (float is not charging!) the battery very slowly discharges. I had the LVD of my 7kW Latronics inverter modified at the factory to 49V

I'm using 2 X FM80s to charge the battery, with 7kW of PV at the moment. In summer the system delivers up to 50kWh per day and DOD is often 80% in the mornings, as I have a large water chiller running to keep my aquaponics system water cool enough for rainbow trout. The rest of the year the nightly DOD is generally 50-60%.
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Re: what about lithium ?

Post by timmartin » Mon Apr 30, 2018 4:27 pm

Gordon-Loomberah wrote: Since I reconfigured the cells from 8S2P to 16S nearly 4 years ago, I haven't been using a BMS. I Absorb for about 3 hours at 55.2V and float at 53.5V. At that float voltage (float is not charging!) the battery very slowly discharges. I had the LVD of my 7kW Latronics inverter modified at the factory to 49V
Interesting. I bulk charge to 55.6 and don't absorb at all. Then float at 54.4. I got these through a combination of someone else and the CALB's documentation (which was light to say the least). How did you arrive at your settings?

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Re: what about lithium ?

Post by Gordon-Loomberah » Mon Apr 30, 2018 4:52 pm

If you only bulk charge to 55.6V then float at 54.4V, the battery will still be charging, just at a slower rate- it wont really be float, just slow charge.

I monitor my system with a Graphtec data logger, so am able to keep an accurate record of the SOC. My float voltage is set to be fractionally under where the battery voltage would sit with no charging and no load, so once the FM80s go to float, the loads are all met by solar alone (assuming the sun is out and loads aren't greater than available power), plus <<1A from the battery.
I arrived at my Absorb voltage after initially charging to a much higher voltage based on the recommendation of the supplier- the cell balancers don't bleed off any current at <3.6V, so I was going to 3.65V (average), but after some reading, decided that wasn't good for longevity. I then eventually arrived at 55.2V = 3.45V/cell as a balance between time required in absorb, and not shortening the battery life too much. When the days are short in mid winter I usually up the voltage a little to reduce charging time within the reduced sun hours.
I found thay the battery still had ~90% of original capacity when I I did some deep overnight discharges in summer.
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Re: what about lithium ?

Post by dazzcat » Sun May 13, 2018 2:12 am

A bit off topic, but why is the CALB batteries rated at only 2000cycles vs 10,000 of Simpliphi, both are Lithium iron phosphate chemistry.

My guess is a lot comes down to the additives they put into the lithium salt electrolyte, according this scientist on youtube* (very worth while watch), he said additives can have a 10fold increase in cycle life with the right combination, hence why Tesla has nailed very long cycle life with cobalt/nickel/aluminum chemistry which i believe originally had poor cycle life.

Also in any case it pays to be cautious of cycle life claims if the lithium manufacturers cycle tests the batteries fast avoiding the battery spending too long in higher voltage states causing parasitic reactions, also according to the youtube lecture if you cycle lithium batteries over a longer period the cycle life is significantly reduced (more align with off grid use). But I believe the situation can be improved by not going over 90% SOC anyhow?

*https://www.youtube.com/watch?v=pxP0Cu00sZs&t=3917s

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Re: what about lithium ?

Post by gtarolli » Sun May 13, 2018 9:06 am

The latest Simpliphi app note specs the battery life as follows, the 100% DOD isn't that much different than the CALB number, but it didn't specify DOD - seems like you have to make sure you compare apples to apples. I'll let you know in a few decades if the Simpliphi batteries hold up ...

DOD CYCLES
=== ======
80% 10,000
90% 5,000
100% 3,500

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- 2 x Out Back 3kw 230v inverters
- 16 x 150ah lead acid AGM battery bank
- 10 x 223w Hyundai panels.
- Pentrametric BM
Location: New Zealand
Contact:

Re: what about lithium ?

Post by dazzcat » Sun May 13, 2018 2:09 pm

Yep I believe that is close to be apples with apples. CALB states 2000cycles at 80% DOD @ 0.2C discharge, not that flash. But the other large manufacturer of Lifepo2 cells Winston use yttrium in the cathode as well, they claim 5000cycles @ 80%DOD, an improvement but no where near the 10,000 of Simpliphi, what's their secret ha? We talking Chinese made vs USA made, but not sure if the actual cell chemistry is made in USA or not?

I'm left wondering if Lefepo2 is even that suitable for off grid because we don't really need the energy density. I think lithium titanate could be the future? 20,000-30,000 cycles at 100% DOD for 2.3v cells.

gtarolli
Forum Guru
Posts: 312
Joined: Thu Dec 21, 2017 10:39 am
My RE system: Outback: off-grid
- 1 GS8048A, Mate3, FlexNetDC, Hub10.3
- 2 FLEXmax 80
- 1 FLEXmax 60
- 30 (10x3) 300w panels (9000w total)
- 6 SimpliPhi 3.4 kWh LI batteries (400ah , 20kWh)
- 1 Honda 3000 generator + one spare
Location: Wainiha, Kauai, HI

Re: what about lithium ?

Post by gtarolli » Sun May 13, 2018 2:25 pm

Here's the story of Simplifi: http://simpliphipower.com/about-us/
they have been making LiFP batteries for a long time, and have innovated a lot (I hope!) with chemistry and BMS. I am crossing my fingers that this is the classic: you get what you paid for, because I paid a lot and I'm counting on these batteries lasting longer than me :-) at least me living off-grid.

dazzcat
Forum Whiz
Posts: 30
Joined: Thu Apr 19, 2018 1:20 pm
My RE system: - 2 x FM80's
- 2 x Out Back 3kw 230v inverters
- 16 x 150ah lead acid AGM battery bank
- 10 x 223w Hyundai panels.
- Pentrametric BM
Location: New Zealand
Contact:

Re: what about lithium ?

Post by dazzcat » Sun May 13, 2018 2:38 pm

I would say they are awesome, I love their modular design. They are not cheap though, however current lithium prices are high, so in a few years they when lithium prices are expected to drop, hopefully lithium batteries drop over all. Though if it's true they last 5 times that of CALB battery then over a long period they are going to be cheaper for sure.

Does Simpliphi state their test conditions? Be good to see if they have tested them under conditions more similar to off grid use.

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