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DIY 24-volt 560Ah LiFePO4 battery (272x2=544Ah) with Electrodacus SBMS0 and Electrodacus DSSR20

michael d

off-grid solar pilgrim
Joined
Dec 15, 2019
Messages
728
Location
South Dakota, USA
1st off, I like the SBMS0 and the DSSR20 set up on 24-volt. if you want to play with higher voltage, look in another thread.
I purposely bought the 60 cell 250-watt panels to match up with the Electrodacus SBMS0.
I also purposely bought the Electrodacus DSSR20 to use as my solar charge controllers.
the Electrodacus dssr20 is a digital solid-state relay that is controlled by the Electrodacus SBMS0.
I purposely bought 32 280 amp LiFePO4 3.2Volt cells to make a 48-volt bank but chose to go with the 24-volt battery builds instead.
Glad I went with 24-volt on these.
most say they are really only 272Ah cells but the vendor claimed they would do 285Ah.
I bought Lishen 272Ah cells that are supposed to produce 285Ah.
I do not believe I need to get every last Ah out as I plan to run them from 3.2 to 3.55 volts for a long lifetime on an off-grid system.
I am not interested in grid-tie. they have no incentive to pay me.
potatoes potatas! :cool:
 
more as I get time.
here is a sneak preview.
 

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Christmas day output with 2 panels to the 24-volt 16 272Ah cell Lishen battery bank (3.2volt x272Ah x 16 cells = 13926.4 Wh or 13.9264KWh capacity. they are hooked to an Electrodacus DSSR20 which is then controlled by the Electrodacus SBMS0. the picture start at 8 am and the last one is about 1:20pm20201225_081227.jpg20201225_085849.jpg20201225_111029.jpg20201225_131646.jpg
 
January 1st, 2021 Electrodacus SBMS0 monitoring the 24-volt 16cell 272Ah Lishen prismatic battery bank with 4 panels connected 250 watts each(2 in parallel to each Electrodacus DSSR20) output update.
591 watts into the battery at 21amps! and balancing while charging. cranked on the inverter to use about 400 watts to charge the other
LiFePO4 battery bank I am putting together and run lights and such in the off-grid insulated solar power shed.:cool:
2 panels face south and 2 panels face west. all panels mounted at 45 degrees. it was about 17 degrees Fahrenheit outside today.
 

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Looks nice! May I ask why you choose for a 24V setup?
the Electodacus will only work with 24-volt but can control up to 18,000 watts of solar panels.
each 24-volt 272 Ah Lishen 16 cell 2P8S battery has 13926.4 Wh capacity. 2 will have 27,852.8 Wh, and 4 will have 55,705.6 Wh capacity.
Low-Frequency, Pure sine wave Split Phase 6000-watt inverter divide by 24 volt = 250 Amps. I am using 400 Ampclass T fuses and 4/0 wire to the inverters. it will be a redundant system and I plan to use the DSSR20 with inversion as a heating source.
I specifically designed this system around the Electrodacus SBMS0 and the Electrodacus DSSR20 for the 3 decimal place monitoring and balancing and protecting the new LiFePO4 battery banks, along with wanting to specifically use the excess electricity for heating.
one big uninterruptible power supply. 24-volt is a lot safer than 48-volt. 48-volt Direct current system has an increased danger factor if you make a small mistake. Electrodacus's components are designed for long term use.
 
Hi Michael, I’m building a similar system. I’ve already ordered 20 272Ah cells from Michael Caro. They should be in soon and am now researching the components I need to support it. At the moment I haven’t ordered anything. Your post introduced me to DSSR20 and SBMS0. Does the DSSR20 replace a MPPT controller and the SBMS0 replace a regular BMS? If this is a basic question, please excuse the ignorance. I’m a DIY’r in the deep end of the pool on this stuff.
 
Hi Michael, I’m building a similar system. I’ve already ordered 20 272Ah cells from Michael Caro. They should be in soon and am now researching the components I need to support it. At the moment I haven’t ordered anything. Your post introduced me to DSSR20 and SBMS0. Does the DSSR20 replace a MPPT controller and the SBMS0 replace a regular BMS? If this is a basic question, please excuse the ignorance. I’m a DIY’r in the deep end of the pool on this stuff.
yes, the Electrodacus DSSR20 replaces the MPPT essentially if you have 60 cell or 72 cell solar panels to match up with it. the Electrodacus SBMS0 can control an MPPT but I chose to go with the Electrodacus SBMS0 with Electrodacus DSSR20 both made By Electrodacus out of Canada. Dacian at Electrodacus will quickly respond to your questions.
it takes 1 Electrodacus DSSR20 for every 2 solar panels in series. The Electrodacus DSSR20 is a solid-state relay and will easily outlive any MPPT as there is no electrolytic capacitor to break down. The SBMS0 is essentially a computer controller that monitors the LIFEPO4 battery banks but will only do up to 8S configuration (24-volt - a safe voltage for the DIYer). The Electrodacus SBMS0 can control up to 18,000 watts of solar panels. and it can also divert excess solar electricity into heat for your house. I bought 4 of the Electrodacus DSSR20's with diversion to try out the heating, but have not got to that part yet.
I bought 16 Electrodacus DSSR20's without diversion to control 40 used 250watt 60 cell solar panels and to specifically charge the LiFePo4 battery banks. (10000 wats of solar panels). I have 32 Lishen 272Ah cells and will soon be getting 32 more so in the more final phase I will have 64 272Ah Lishen cells in 4 separate 24-volt banks.
The Electrodacus SBMS0 balances your cells as it charges - it is phenomenal and it shows the voltage in 3 decimal places for each of the 8 battery cells. You can combine cells in parallel as I did 2P8S for a 24-volt battery bank. It works great.
I have seen a guy who did 3P8S but I chose to go 2P8S for the battery configuration.
I think you could do 4P8S without any problems as many people already do this.
I am not an electric expert but a DIY type person who studies a lot before doing it.
you will want to get a bench type charger to initially charge your cells in parallel to bring your voltage up before assembling your battery bank.
I bought a Riden 6012-W -- it works great and also does the 3 decimal point accuracy. I just received the newer Riden 6018-W for more power.
I think the Electrodacus SBMS0 is the way to go. the battery protection and monitoring is second to none for the price. the Electrodacus SBMS0 with wifi is what I bought so I will be able to see it all on a bigger screen.
I am working to add panels slow but sure in pairs. I was reinforcing the solar panel array yesterday in the snow for solar panels to be mounted.
You might look at Electrodacus.com for a bit more information.
I bought pre-made parallel cables with MC4 ends for easy plug and play.
I am making the rest of the cables myself with crimpers and such and wire bought in bulk off the internet.
yes, the SBMS0 replaces a regular BMS. it far exceeds most all BMS capabilities for a small price. :cool:
my DIY solar panel array is treated 2x6 lumber and unistrut to mount the solar panels to. I have a south-facing solar array and presently working on a west-facing solar array.
I use 10AWG PV wire from the solar panels into the Electrodacus DSSR20's and onto the bus bars. the Electrodacus SBMS0 is connected with small control wires. I used 22 gauge solid strand cat 5 cables with twisted pairs.
I used an 18 gauge wire solid strand to connect the Electrodacus DSSR20's in parallel.
The Electrodacus SBMS0 controls them. SBMS0 = solar battery management system. the 0 just means model number.
DSSR20 = digital solid state relay. I am not sure but I believe the 20 means it can control 20 amps of solar panels.
 
I now have 6 panels hooked up. every 2 panels are 250 watts each and so there are 500 watts of PV panels to each DSSR20. 2 sets are pointed west at a 45-degree angle and get no sun until later in the day. 1 set of 2 panels is on a south-facing array at 45 degrees and get a lot of sunshine and put out the most energy to the 24-volt 16 cells 272Ah Lishen battery bank 2P8S for 13,926.4Wh potential capacity. I have been running the 6000-watt low-frequency pure sine wave split-phase inverter every day at low watt usage. It has been snowing and raining and cloudy for about 3-4 days and likely cloudy the next 2 days. today January 8th, 2021 I noted that I was still getting 140 watts through the clouds with no sun whatsoever peaking through all day. the battery was charging and I only ran a few lights but I also hooked up a 24-volt led light directly to the battery with a circuit breaker as its on-off switch. works great no inverter required. more later, just an update --- the dssr20' work great. the west array is a bit closer to the off-grid power shed than the south array. I should be working to connect more on the south-facing array but the west array structure was more complete so I had to add more panels as quick as a slow man can --- all by myself!!!! :cool: 1.5Kw of panels and growing!
 
I completed the rest of the solar panel array superstructure build yesterday in 30 degrees F weather but no wind. thanks to the lord; I also received notice from FedEx finally that my 2nd batch of 32 Lishen 272Ah cells ore on their way to me. they arrived at the port on December 22nd, 2020 -- it has taken this long to unload the container from the ship in Long Beach, California and clear customs, and finally get into FedEx hands. Very slow I ordered these and paid for them on November 18th, 2020.
I will be mounting more solar panel pairs in the next few days. each solar panel weighs 41 pounds, so it is a bit of a task to get them mounted on the 45-degree angle of the solar array superstructure which I built out of 2x6 treated lumber and unistruts.
no pain no gain! I feel the pain as a 59-year-old spring chicken should I guess. :cool:
yesterday through the clouds the solar array was still putting out 240 watts and charging the 16 cell 272Ah 24-volt battery bank (2P8S wiring configuration) with a potential capacity of 13926.4Wh. ---no sun got thru the clouds. totally cloudy but no wind and maybe another 1/10th inch of snow overnight.
 
today i hooked up 2 more 250 watt 60 cell PV panels to the Electrodacus SBMS0. the 2 panels are hooked to the DSSR20 in parallel as are the other 2 panels. so there are 2 Electrodacus DSSR20's controlled by 1 Electrodacus SBMS0.
they were putting out 819.8 watts at 30.194 amps. 16.066 amps were going to charge the 24-volt 2P8S Lishen 16 cell battery bank. while 14.128 amps were being used by the dc lights and the inverter. I was charging some of the other Lishen 272Ah cells for the next 24-volt battery bank I am assembling from the solar power being generated and harvested all off-grid.
 

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yesterday January 13th, 2021: I hooked up 2 more 250-watt 60 cell PV panels on the south-facing array. the 6 panels (1.5Kw array) were producing 1162.7 watts and more at times and charging the 2P8S 24-volt LiFePO4 battery bank with 41.898 amps. see pic below. I think the only load at the time was some dc light hooked directly to the 24-volt battery. this south-facing array is about 60 feet of 10 gauge PV (red for positive and black for negative) wire away from the DSSR20 before being controlled by the SBMS0. the SBMS0 is the BMS. it works great. The DSSR20's are the solid-state charge controllers putting out as much as the solar panels will do. every 2 panels are paralleled at the array so then they go directly to the DSSR20's. 2 panels per DSSR20. :cool:
 

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cells arrived Sunday January 17th, 2021 via FedEx at 920am. slowed by the midwest blizzard by 3 days.
yesterday I labeled all cells on the new 32 Lishen 272Ah cells with red tape on the positive end and a Dymo label that says positive. Lishen 272Ah cells have no labels but the black plastic terminal is positive and the tan plastic terminal is negative. only enough busbars to parallel 16 of the 32 cells to do the top balancing. but I ordered some hydraulically crimpable lugs with 1/4 inch holes to make some cell interconnect cables. the lishen cells have 6mm stud holes -- essentially a 1/4 inch for American measurements. the solar panels and the existing 2P8S LifePO4 battery bank and the 6000-watt low frequency split phase inverter is doing all the charging of the new cells off-grid 24/7 right now.
 

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Looks awesome. Will be keeping an eye on your progress. I am going down a very similar path.
 

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yes and no. I used a bench charger to initially charge the cells but never got them close to 3.65. too impatient. I hooked up 16 cells 2P8S for a 24-volt battery bank and used the SBMS0 to charge it up more with the solar panels; of course, I have the inverter connected for the load and I have dc lights and I also have 2 chargers running off the 24-volt battery bank (2P8S Lishen 272Ah 16 cells); one charger is charging 8 272Ah cells in parallel for the top balance of those 8 cells at 3.5 volts right now - I will move it up to 3.65 later; the other charger is charging 8 272Ah cells connected in series(for an 8S 24-volt battery) @27.5 volts. both chargers are running off the inverter off-grid from the solar electricity produced yesterday. the inverter has been running off-grid 24/7 charging the new 32 Lishen 272Ah cells. when the sun is out it is getting about 1200 watts charging the battery and also running the load out of the battery. yesterday the battery was fully charged at about 1 or 2 in the afternoon. I turned on the dc lights, ac lights, and turned up the bench chargers.
the 2 very accurate bench chargers I am using are Riden 6012w (60 volts at 12amps max charging) and Riden 6018w (60 volts at 18 amps max) which are plugged into the inverter so they are running off-grid 24/7 at the moment.?
the SBMS0 brings the battery back up to full charge in a few hours of good sun. just exercising some of the Lishen cells as I increase capacity etc. I bought Seltern 1/4 inch tinned copper lugs(arrived yesterday) to make a few cable interconnects with 6 gauge wire to balance and parallel balance some more cells. the cells only came with 4 busbars per 4 cells --- but in reality, a person needs twice that many busbars ( to parallel top balance 8 cells need 16 bus bars to interconnect 8 cells at the same time).
I think the SBMS0 could do all the charging for the new Lishen 272Ah cells, but most members on the forum reccomend doing a top balance 1st.
I believe the SBMS0 can do it alone and have implemented that on 2 8S battery configurations.?

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Hi Michael, I’m building a similar system. I’ve already ordered 20 272Ah cells from Michael Caro. They should be in soon and am now researching the components I need to support it. At the moment I haven’t ordered anything. Your post introduced me to DSSR20 and SBMS0. Does the DSSR20 replace a MPPT controller and the SBMS0 replace a regular BMS? If this is a basic question, please excuse the ignorance. I’m a DIY’r in the deep end of the pool on this stuff.
you will want to get double the bus bars to top balance in parallel. I bought some 6 gauge lugs with 1/4 inch holes to make cable interconnects so I can balance more cells. my Lishen cells came with 4 busbars per 4 cells. also if you get the 6mm diameter x 20mm long set screws/ aka grub screws with flange nuts that is the way to go.
my 1st 32 Lishen 272Ah cells came with 16mm long grub screws and flange nuts. the 16mm is not long enough for some connections so you want 20 mm long ones. the second set of 32 Lishen 272Ah cells came with bolts and washers.--- they did not fit good or tighten well -- I replaced all of those bolts with 20mm x 6mm grub screws. you will find that the grub screws sticking up are better for mounting the busbar interconnects together with fewer problems of accidental arc-ing between cells. do not over tighten the set screws!!!!!! snug them down carefully -- they are only 6mm which is 1/4 inch approximately and you will hate yourself if you strip one out. I plan to use lock-tite on the threads also.
 

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