Help with 128 batteries each one is 280ah, and want to configure for 48v system.

kromc5

Solar Addict
Batteries year round will see 65-72f.

Hoping to charge between 65-75%

Based on increase in cell life.

I was thinking of doing 16s by 8 as the diagrams were readily available and easy to follow. I kept
finding that the recommend charging is to be done by the inverter charge controller not the bms. My thoughts were
that having 8 batteries and not using the bms for cutoff could be problematic. Since yesterday I have been trying
to find different battery configurations and stumbled upon the 16S11P but I'm unable to find a diagram
on wiring this battery. If the math is right this is a much better configuration and creates a single battery
which has a much higher kwh rating. My inverter and extra charge controller require 48v.


16s
16128.0
129,024wh

16S11P
177408.0wh

If anyone has suggestion on battery configuration or it doing a 16S11P would not be the right way I would appreciate any help.

I have emailed orion, chargery and batrium, orion support is great and very helpful, chargery was also quick to respond. I'm still waiting on
and email from batrium but two emails have not been answered. I like the idea of active balancing and leaning towards batrium but wanted
to confirm if I can use with my configuration.
 

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jasonhc73

Cat herder, and dog toy tosser.
Your kWh equation looks odd.
kWh = Nominal Voltage times the amp hours
(don't remove the units. Volts times Amps equals Watts)

Start with just one cell.
3.2 v x 128 ah = 409.6 Wh

Make one battery.

4 cells make a ~12v battery
12.8v x 128 ah = 1,638.4 Wh or 1.6 kWh

16 cells make a ~48v battery
51.2v x 128 ah = 6,553.6kWh or 6.5 kWh

11p, ie 11 batteries in parallel
6.5 kWh x 11 = 72,089.6 or 72 kWh

If you want to parallel the cells before you series them, you can do that also.
As soon as you connect one battery to another, you just made a new battery.
The equation is still the same.

Make one battery with two cells in parallel first.

3.2v x 128 ah x 2 = 819.2 Wh
Now do it with 11
3.2v x 128 ah x 11 = 4,505.6 Wh or 4.5 kWh
Now do a 16S (48V configuration)
16 x 3.2v x 128 ah x 11 = 72,089.6 or 72 kWh
 
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kromc5

Solar Addict
Your kWh equation looks odd.
kWh = Nominal Voltage times the amp hours
(don't remove the units. Volts times Amps equals Watts)
Thank you for the response, each one is 280ah, my title might be slightly misleading the way I worded it.
 

HRTKD

Boondocker
I would stick with a 16s battery, with each battery having its own 16s BMS. That gives you 8 batteries.

It would seem to me that your selection of BMS is much larger if you stay with 16s as opposed to say 32s or larger.

Yes, I would use a BMS. Think of it as the final authority on maximum charge. All other components such as solar charge controllers and AC-DC converters must understand how to properly charge a LiFePO4 battery.

With that many batteries, I would look into a battery balancer that keeps the voltage balanced between all 8 batteries.
 

jasonhc73

Cat herder, and dog toy tosser.
Sorry about that, I read the message and totally missed the title part.

8 x 51.2v x 280 ah = 114,688 or 114 kWh.

You will basically have 8 batteries of 14 kWh each. (I have 4 in the same capacity ordered)

I plan to make 4 sets of 16, each with their own Chargery BMS.
I am putting all 4 sets to a bus bar, aka a combiner, then to the charge controller.

Each set of 16 as its own battery to me will provide maximum longevity. I think I am overkilling with 4 BMS's going to each set.
My thinking is about the sheer size of the cells having so much capacity, and I want every single cell monitored.
 

kromc5

Solar Addict
Thank you for the response, each one is 280ah, my title might be slightly misleading the way I worded it.

Sorry about that, I read the message and totally missed the title part.

8 x 51.2v x 280 ah = 114,688 or 114 kWh.

You will basically have 8 batteries of 14 kWh each. (I have 4 in the same capacity ordered)

I plan to make 4 sets of 16, each with their own Chargery BMS.
I am putting all 4 sets to a bus bar, aka a combiner, then to the charge controller.

Each set of 16 as its own battery to me will provide maximum longevity. I think I am overkilling with 4 BMS's going to each set.
My thinking is about the sheer size of the cells having so much capacity, and I want every single cell monitored.
If I stick with the 16s then I think chargery would be much more cost efficient.
I would stick with a 16s battery, with each battery having its own 16s BMS. That gives you 8 batteries.

It would seem to me that your selection of BMS is much larger if you stay with 16s as opposed to say 32s or larger.

Yes, I would use a BMS. Think of it as the final authority on maximum charge. All other components such as solar charge controllers and AC-DC converters must understand how to properly charge a LiFePO4 battery.

With that many batteries, I would look into a battery balancer that keeps the voltage balanced between all 8 batteries.
With that many batteries, I would look into a battery balancer that keeps the voltage balanced between all 8 batteries. - I'm still learning can you link to one that you plan to use. I would like to research this as since I was wondering how the cutoff charge/discharge would work with 8 batteries on the inverter?
 

Steve_S

Offgrid Cabineer, N.E. Ontario, Canada
16S, 48V/280AH battery at 0%SOC (all cells at 2.50v) = 40.0V. 11.2 kWh
16S, 48V/280AH battery at 100%SOC (all cells at 3.65v) = 58.4V. 16.352 kWh
The "sweet spot" in general for these cells is between 3.40 to 3.50V at the top and 3.0-2.80V at the bottom and that is exactly where the voltage curve loves to be. As most folks run them 10% below the top & 10% above the top "more or less".

You can charge these cells till you turn as blue as the casing to 3.65V but within an hour of no charge input, they will settle around 3.55V +/- a bit.
Some cells will Deviate when approaching the top or bottom and can cause the BMS to cutoff to protect the cells.

Passive Balancing is not much use for cells above 100AH capacity and most certainly of no use for Unmatched & Unbatched commodity cells.
Active Balancing can pass High volts to Low Volt cells from the high ones. These can range from 1A handling to 10A handling (major pesos). These do work on larger cells as it is transferring power from one cell to the other and leveling them up. I know of only two that are known good & work, they are HelTec Active Balancers & QNBBM Active Balancers. I happen to use QNBBM's. Some BMS' are now coming available with Active Balancing (Heltec for one) and others are working on them.

BTW: I am running "Thrashing Tests" on my own 280AH/8S packs with the QNBBM-8S Active Balancers & Chargery BMS8T BMS. Heavy to Light discharges (225A to 1A) with Heavy (120A) to Light Charging (10A). The cells really do prefer to sit just above 3.45V ea cell, above that level the deviations start to kick in and the cells start to diverge exponentially the higher the voltage gets. I've also been testing them using different voltages for the charging (I'm 24V obviously) from 29.2V down to 27.0V and at the lower voltages they tend to be more "calm" with respect to divergence. My battery systems might very likely consider me Rude & Nasty to them for the thrash testing but it's the only way to know in the Real World how they will hold up. So far 3.45 to 2.90 really does to be the sweet spot.
FYI: EVE states these cells are capable of 1C (280A) discharge BUT they also state that .5C (140A) Charge & Discharge is the recommended C Rate to use. NOT ALL LFP IS THE SAME ! Some can handle up to 3C and higher, those are Very Expensive (think Winston)!

REF: Li-Ion BMS - White Paper - Dissipative vs. nondissipative balancing (a.k.a.: Passive vs. Active balancing)

QNBBM's from DeliGreen (they own the QNBBM brand)

HelTec Smart BMS'

You may want this as well:
https://diysolarforum.com/resources/general-lifepo4-lfp-voltage-to-soc-charts-tables-12-24-48v.109/

For Quick Math Help (the darn formulas)

Hope it helps, Good Luck
Steve
 
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kromc5

Solar Addict
16S, 48V/280AH battery at 0%SOC (all cells at 2.50v) = 40.0V. 11.2 kWh
16S, 48V/280AH battery at 100%SOC (all cells at 3.65v) = 58.4V. 16.352 kWh
The "sweet spot" in general for these cells is between 3.40 to 3.50V at the top and 3.0-2.80V at the bottom and that is exactly where the voltage curve loves to be. As most folks run them 10% below the top & 10% above the top "more or less".
That is very helpful and I will have to read over everything as I'm still trying to grasp all the ideas.
 

Steve_S

Offgrid Cabineer, N.E. Ontario, Canada
That is very helpful and I will have to read over everything as I'm still trying to grasp all the ideas.
Yes, it can become overwhelming with the amount of information to absorb. It is a lot like when Personal Computers came out and the alphabet soup of acronyms etc was too much for most at first, and the buggers haven't stopped adding more "soup".

Now I am gonna take you slightly sideways with your intended project with so many battery packs. It would more than likely be prudent to be looking at using a Distributed or Modular BMS System because of the complexity of operating such a battery bank. 8 Packs in parallel is considerable to manage & control as well as integrating with your equipment. Having 8 packs and coordinating what is going on can be challenging, it's a PITA with just 4 packs which are standalone "Centralized" BMS'.

Now with this level of "investment", you will want a very respectable Tier-1 Inverter & Charging system, such as Victron for example. You haven't mentioned the rest of the supporting gear that goes with such a battery bank.

8X (280AH@48.0V / 13.44 kWh). 2,240AH/107.52kWh total. = Honkin size = honkin charge requirement. The batteries are only as good as the amount of charge you can put into them within a reasonable period of time. If 100% Solar Charging the lowest Sun Hour Days for your area is what is used to calculate the solar capacity needed, which then dictates the SCC's to handle it. If Hybrid Solar & Grid (pull) then there is other things to consider on the Charging & Inverting side.

The bottom line, is the whole package should be figured out and built to operate well and deliver what you expect. A failure to plan is a plan for failure.

Topology (more info):
• BMS: does not include a switch to cut off the battery current
• Protector: includes a switch to cut off the battery current
• Centralized ("spaghetti"): single BMS controller with n+1 wires going to n cells
• Centralized with slaves: single BMS controller connected to a few slave boards, each with n+1 wires going to n cells
• Modular: single BMS controller with n+1 wires going to n cells; expanded by adding more, identical BMS controllers
• Distributed: small board mounted on each cell; BMS controller connected just to the 2 cells at either end of a battery
SOURCE: http://liionbms.com/php/bms_options.php <-- A Goldmine in easy to follow English, lots of tech & manufacturers listed.

Sorry for the more "soup" ;)
 

cinergi

1.21 Jigawatts
You can also consider 4 batteries that are 16s2p which would halve your BMS costs of 8 batteries that are just 16s each.

It's important for us to know your equipment and max system load because that will play a very large role in our recommendations for battery design.
 

kromc5

Solar Addict
You can also consider 4 batteries that are 16s2p which would halve your BMS costs of 8 batteries that are just 16s each.

It's important for us to know your equipment and max system load because that will play a very large role in our recommendations for battery design.

My inverter is the growatt 12kw, with two growatt 120 amp charge controllers. When talking with signature he stated that we would need to just be aware of our total load IE is the heater running / stove or laundry plus appliances and James is in a much larger home. Since I have a new meter I have been wanting to get the time to check all appliances, our heating system, stove etc, the mini split is roughly 20 amps. But with only 12kw I suspect I could easily hit that the max if I was not careful. With 8 16s and the max amps from them I calculated that the max load would long hit the inverter before the batteries were maxed. My sub panels is a 200 amp as well.
 

Steve_S

Offgrid Cabineer, N.E. Ontario, Canada
My inverter is the growatt 12kw, with two growatt 120 amp charge controllers. When talking with signature he stated that we would need to just be aware of our total load IE is the heater running / stove or laundry plus appliances and James is in a much larger home. Since I have a new meter I have been wanting to get the time to check all appliances, our heating system, stove etc, the mini split is roughly 20 amps. But with only 12kw I suspect I could easily hit that the max if I was not careful. With 8 16s and the max amps from them I calculated that the max load would long hit the inverter before the batteries were maxed. My sub panels is a 200 amp as well.
The advantage with 8 Packs in the bank, they will share load & charge and that is Much Easier on the battery assemblies. 12Kw @ 48V is 250Amps potential draw. As I believe that system is Low Frequency, that means a Max Surge potential of 3X means up to 750A raw is possible. As a result of that, we also know that "typically" any single pack within a bank should be able to take the full 250A Draw & charge potential. Usually one would cover the "surge potential" but 750A is kind of high to do so and some BMS' will handle a surge. You can feed a 240V/Split phase 200A panel with this if done right !

BTW a Very True Axiom: It is far less expensive to Conserve than it is to Generate & Store energy. You may want to revisit the Electrical Appliances and weed out the Energy Hogs and replace them with high efficiency or at minimum Energy Star rated equipment. The worst offenders are usually, Hot Water Tank (On-Demand wins), Electric Stove (coil element type being the worst of them all), Electric Dryer, A/C Systems (Mini-splits are much more efficient) ANY Electric heating (baseboard to furnace), Well pumps (some are Really Bad Hogs).
 

jasonhc73

Cat herder, and dog toy tosser.
The DC amp load is not the same as the AC amp load.

A 32 Amp load creates about ~140+ amp DC load on the batteries. Which is about 35 amps per battery(in a 4 battery 48v setup), or only about 2 amp per cell.

With 48V systems the last cable to the inverter is the biggest problem that is if you plan to run all you induction heating things at the same time.

It is very easy to not run the dryer, space heater, stove and pizza cooker, and car EVSE at the same time.
 

kromc5

Solar Addict
The advantage with 8 Packs in the bank, they will share load & charge and that is Much Easier on the battery assemblies. 12Kw @ 48V is 250Amps potential draw. As I believe that system is Low Frequency, that means a Max Surge potential of 3X means up to 750A raw is possible. As a result of that, we also know that "typically" any single pack within a bank should be able to take the full 250A Draw & charge potential. Usually one would cover the "surge potential" but 750A is kind of high to do so and some BMS' will handle a surge. You can feed a 240V/Split phase 200A panel with this if done right !

BTW a Very True Axiom: It is far less expensive to Conserve than it is to Generate & Store energy. You may want to revisit the Electrical Appliances and weed out the Energy Hogs and replace them with high efficiency or at minimum Energy Star rated equipment. The worst offenders are usually, Hot Water Tank (On-Demand wins), Electric Stove (coil element type being the worst of them all), Electric Dryer, A/C Systems (Mini-splits are much more efficient) ANY Electric heating (baseboard to furnace), Well pumps (some are Really Bad Hogs).

I installed a Mrcool Mini and already dropped our bill more than I though: The heating/cooling is a split duct system which when it cools in the basement some cold air always blows upstairs and then if the upstairs is heating some heat always bypasses. I had a feeling my 65f downstairs was costing lots of kwh due to the constant dueling temperate zones.




Thread detailing installation progress:
 

ericgrand

Solar Enthusiast
I don't follow you on the 2A/cell...Amp are constant over a serial connection. So if you have 16 cells in serie to achieve a 48V pack, and this pack is delivering 140A, then each cell is delivering 140A also...
If you have 4 48V pack in parallel, then, each pack deliver 35A, but each individuel cell of each pack will be delivering 35A also...
 

kromc5

Solar Addict
The DC amp load is not the same as the AC amp load.

A 32 Amp load creates about ~140+ amp DC load on the batteries. Which is about 35 amps per battery(in a 4 battery 48v setup), or only about 2 amp per cell.

With 48V systems the last cable to the inverter is the biggest problem that is if you plan to run all you induction heating things at the same time.

It is very easy to not run the dryer, space heater, stove and pizza cooker, and car EVSE at the same time.
James at signature said to login and watch the load draw on growatt inverter and be aware of what is being run.
 

Steve_S

Offgrid Cabineer, N.E. Ontario, Canada
I don't follow you on the 2A/cell...Amp are constant over a serial connection. So if you have 16 cells in serie to achieve a 48V pack, and this pack is delivering 140A, then each cell is delivering 140A also...
If you have 4 48V pack in parallel, then, each pack deliver 35A, but each individuel cell of each pack will be delivering 35A also...
If the battery pack is pushing out 140A, that is done collectively from the cells within. With a Smart BMS you can watch as the different cells discharge by their individual cell voltage fluctuations which also affects the direct amps they are outputting. Same occurs during the charge in reverse, the cells fluctuate as they take in charge. It isn't "flat" across all the cells in the pack.
 

ericgrand

Solar Enthusiast
If the battery pack is pushing out 140A, that is done collectively from the cells within. With a Smart BMS you can watch as the different cells discharge by their individual cell voltage fluctuations which also affects the direct amps they are outputting. Same occurs during the charge in reverse, the cells fluctuate as they take in charge. It isn't "flat" across all the cells in the pack.
I'm sorry, I think there is a misunderstanding here...In Serie, all cells are pushing the same Amp amount. Voltage maybe different. But definitely, if battery is outputting 140A, then all cells are outputting 140A. But as there internal resistance may vary, the total voltage is the sum of all individual voltage.
 

cinergi

1.21 Jigawatts
I'm sorry, I think there is a misunderstanding here...In Serie, all cells are pushing the same Amp amount. Voltage maybe different. But definitely, if battery is outputting 140A, then all cells are outputting 140A. But as there internal resistance may vary, the total voltage is the sum of all individual voltage.

This is correct. 140 amps at the battery must be 140 amps at every cell by definition (the current must flow through the cell).
 
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