48V 16S 280ah EVE Cells + BMS

[jibberishballr]

Hi all,

New here and still learning solar as I go. I installed a 10.2kwh system on the roof and two MPP LV6548 inverters (running split phase) with some car batteries temporarily keeping them running.

I plan on ordering 16 3.2V cells to get a 48V battery bank with 280ah. My general understanding is to find the amperage for your BMS you want to understand your charge and discharge decay rate (1C and 2C is my understanding of these batteries) and max watts you would need. I'm still a little confused on how to do math on what a 10.2kw system should be putting out but am logging data to see real world numbers starting today. I assume that 100a would not be enough as that would limit me to 4800 watts (48vX100amps) but correct me if I'm wrong on how I'm figuring that out.

At the end of the day, I want to best supply my array with the goal of eventually being fully off grid. I believe my array size should be adequate for the kwh I use on a monthly basis (paired with decent storage) and will be making some changes to lower consumption as well. With a system that size I was planning on getting the initial 48V 280ah and possibly doubling up to 560ah in the future. With that in mind, what sort of BMS setup (one or multiple, what amperage, etc.) would make most sense? I've heard mixed suggestions and am a little overloaded with info atm.

Happy for any suggestions and advice.

Thanks!

 

[sunshine_eggo]

6500W/48V/85% = 160A

 

[jibberishballr]

6500W/48V/85% = 160A

Thanks for the suggestion. Few questions:

1. How did you arrive on 6500W and 85%?
2. Is your suggestion based on the 280ah or the potential 560ah?
3. Based on that suggestion, does a single 200a BMS make sense, or would that come with its own set up problems? What sort of setup is recommended?

 

[sunshine_eggo]

Thanks for the suggestion. Few questions:

1. How did you arrive on 6500W and 85%?

because I missed that you had two.

85% is because inverters are only about 85% efficient at max power.

6500W * 2 / 48V / 85% = 318A

1. Is your suggestion based on the 280ah or the potential 560ah?

Doesn't matter. That's the amount of current you need from the battery for that power.

1. Based on that suggestion, does a single 200a BMS make sense, or would that come with its own set up problems? What sort of setup is recommended?

Nope. I would consider 2X 16S 280Ah batteries each with 200A BMS as a solution.

 

[jibberishballr]

because I missed that you had two.

85% is because inverters are only about 85% efficient at max power.

6500W * 2 / 48V / 85% = 318A



Doesn't matter. That's the amount of current you need from the battery for that power.



Nope. I would consider 2X 16S 280Ah batteries each with 200A BMS as a solution.

Thanks for the details. Is there any downside to running the 200A BMS? I'd heard conflicting opinions on that level amperage being suboptimal for the batteries.

 

[houseofancients]

Thanks for the details. Is there any downside to running the 200A BMS? I'd heard conflicting opinions on that level amperage being suboptimal for the batteries.

no , been running 200a bms'es for quite some time now.
where did you get the idea 200a is sub optimal for 280a cells ?

 

[jibberishballr]

no , been running 200a bms'es for quite some time now.
where did you get the idea 200a is sub optimal for 280a cells ?

I think I had read it on another post where someone was talking about the C rate and having too high of amperage being detrimental to the batteries life. Are there any downsides to having too high of an amperage BMS?

 

[sunshine_eggo]

280Ah typically have a 0.5C charge rate and a 1.0C discharge rate. I don't think that unit could charge anywhere near 280A (140A * 2) or discharge at 560A (280A *2).

 

[jibberishballr]

no , been running 200a bms'es for quite some time now.
where did you get the idea 200a is sub optimal for 280a cells ?

Here's the thread where I was confused on running the continuous amperage:

BMS for 280ah 16s 48v Lifepo4 connected to Growatt 5000es

Good morning working on picking up a 48v BMS for my 280ah eve cells. Any recommendations, was leaning towards overkill 100amp 48v 16s. But don't really need low temp protection for my setup. Thoughts on the best option and how many amps would be best for this setup. I'm running 2 x growatt...

diysolarforum.com

Seems like most folks either go with the Dalys, Chargery, or JBD. Not trying to spend a fortune but get something that works so I can get these batteries up and running.


Any suggestions and where to get them shipped from in the US?
I saw this one on Amazon which seemed like a good deal?

https://smile.amazon.com/DALY-Programmable-Configurable-Protection-Bluetooth/dp/B08VJ3L5QS/ref=sr_1_4?crid=28ZHLAN27KJIQ&keywords=jbd+bms+48v&qid=1661701235&refinements=p_72%3A1248879011&rnid=1248877011&s=electronics&sprefix=jbd+bms+48%2Caps%2C149&sr=1-4

 

[houseofancients]

Here's the thread where I was confused on running the continuous amperage:

BMS for 280ah 16s 48v Lifepo4 connected to Growatt 5000es

Good morning working on picking up a 48v BMS for my 280ah eve cells. Any recommendations, was leaning towards overkill 100amp 48v 16s. But don't really need low temp protection for my setup. Thoughts on the best option and how many amps would be best for this setup. I'm running 2 x growatt...

diysolarforum.com

Seems like most folks either go with the Dalys, Chargery, or JBD. Not trying to spend a fortune but get something that works so I can get these batteries up and running.


Any suggestions and where to get them shipped from in the US?

you can simply order the directly from seplos.
delivery time is about 5-8 working days, the bms'es get shipped by fedex ( in my case anyway) i paid 215 shipped when i ordered mine

 

[jibberishballr]

you can simply order the directly from seplos.
delivery time is about 5-8 working days, the bms'es get shipped by fedex ( in my case anyway) i paid 215 shipped when i ordered mine

I went on Seplos' site and inquired about pricing for their 200a BMS but it was a little confusing. Are they the manufacturer for the chips that go in all the aforementioned BMS' or are they specific to one of the ones I mentioned above?

The Daly seems like a pretty good deal and I get amazon protection with quick delivery...any reason not to go with those?

 

[houseofancients]

I went on Seplos' site and inquired about pricing for their 200a BMS but it was a little confusing. Are they the manufacturer for the chips that go in all the aforementioned BMS' or are they specific to one of the ones I mentioned above?

The Daly seems like a pretty good deal and I get amazon protection with quick delivery...any reason not to go with those?

do a forum search, determine is you want communication and stacking of multiple batteries.

cant and wont determine for you what you should or should not buy

 

[jibberishballr]

do a forum search, determine is you want communication and stacking of multiple batteries.

cant and wont determine for you what you should or should not buy

I'm a little overloaded with reading threads and the nomenclature seems to be a little all over the place. Are there any stickied or reliable threads you'd suggest?

If battery stacking refers to running the cells in series (to get 48v from 16cells at 3.2v) then that's the plan. If not, then I'm not sure I follow...

For communication do you mean sending and receiving data around readings of the batteries (i.e. SOC and SOH) or are you referring to more hands on (i.e. cell balancing, charge control, etc.) or something else?

I really just want the setup to be safe and as close to optimal without having to be managing it all the time. I'd prefer active balancing (but only understand it in concept) as I am new to the world of BMS'.

 

[John Frum]

.

 

[Steve_S]

Recommend JK-BMS JK-B2A20S20P
BlueTooth App (IOS & Andriod)
RS485/Canbus communications
2A Active Balancing, Transfers hi volts to lo volt cells.
On/Off Switch,
Optional RS485 CAN module and LCD display Adapter




















BMS
https://www.aliexpress.com/item/1005003104573871.html
Extras

10.1US $ |Jikong BMS RS485 CAN module and LCD display Adapter|Battery Accessories & Charger Accessories| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

Manual

JK/JKBMS INSTRUCTION.pdf at JK-BMS · NEEY-electronic/JK

Contribute to NEEY-electronic/JK development by creating an account on GitHub.

github.com

 

[jibberishballr]

View attachment 109185

Recommend JK-BMS JK-B2A20S20P
BlueTooth App (IOS & Andriod)
RS485/Canbus communications
2A Active Balancing, Transfers hi volts to lo volt cells.
On/Off Switch,
Optional RS485 CAN module and LCD display Adapter




















BMS
https://www.aliexpress.com/item/1005003104573871.html
Extras

10.1US $ |Jikong BMS RS485 CAN module and LCD display Adapter|Battery Accessories & Charger Accessories| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

Manual

JK/JKBMS INSTRUCTION.pdf at JK-BMS · NEEY-electronic/JK

Contribute to NEEY-electronic/JK development by creating an account on GitHub.

github.com

This is very helpful. Thank you!

 

[Clifton]

I run the JKS 200A with twin 6500EG's, 9.2kw panels and 16 280a batteries. I ordered from Hankzor on aliexpress. Make sure to get it with a power button so you aren't jumping it with a battery to start it. I think that is default now. I just used the bluetooth app. I run a lot on mine but staggered to keep the load low and a 6000 btu window unit all night non stop 8 pm to 5 am. I can sometime make it until the sun comes back up, sometimes it switched back to grid at 4 am. It I didn't live in Phoenix it would be ok. I used what others have used for the bms settings except max input/output amps. I never top ballanced. Cell #7 was initially off by a lot for a few weeks but they are all good now.