Does the BMS have to be connected to the inverter?

[Ampster]

what BMS's are peeps using now? im planning on 2p16s or at least i think i am.. 16 cells in series to make a bank and 2 banks in parallel not sure what the difference is between that and 16s2p?? something to do with 1 or 2 BMS's?

I am using an Orion BMS JR2 BMS. My pack is 3P16S which means it is 3 cells in parallel then each group connects with another group for 16 groups. That allows me to use one BMS. I have been using Orion BMSs since I did an EV conversion ten years ago. They are expensive and that was part of my decision to have one pack instead of three with separate BMSs.
As far as the original question in this thread my answer is different than it might have been two months ago. I now have an inverter that can communicate with my BMS and there are certain advantages. I still have a contactor as the last stand against pack failure. One advantage of communication between inverter and BMS is that you can have more control over charging amps at the end of the charging stage. I was able to increase my charging voltage by 0.4 volt or 0.025 per cell which does not sound like much but it gave me a little more capacity. Another advantage in my case was that the Orion BMS has a much better Coulomb counter so I had more reliable SOC percentages. I still need to make sure the pack is fully charged every few days to make sure SOC is reset at 100%.

 

[Markvk]

Hi Ampster.

Thanks for getting back to me and sorry for the delayed reply. Im really struggling to get my head around how to do what i originally intended which was this.



Im starting out with 6KW of panels, this isn’t likely to change due to space limitations

Im looking at this inverter because it allows parallel configuration of up to 10 units, im starting with 1 and aiming for 3 eventually depending on peak load after the pump is fitted.

[https://www.ginlong.com/energy.../s5_eo1p_4-5k_48_en.html](https://www.ginlong.com/energy.../s5_eo1p_4-5k_48_en.html).

And a 16s 48v lipo battery with this BMS.

[https://www.fogstar.co.uk/.../jbd-bms-for-lifepo4-with...](https://www.fogstar.co.uk/.../jbd-bms-for-lifepo4-with...)

Its my intention to increase the battery/inverter side of this with 2 more banks that will all run in parallel, The idea being to catch and use every photon that’s there and charge the banks on off peak elastictrickery to use during peak.

Looks like the inverter that i picked is no good because its not grid tied, and parallel hybrids are not available. does anyone have any idea how to do this?

 

[Sanwizard]

Hi Ampster.

Thanks for getting back to me and sorry for the delayed reply. Im really struggling to get my head around how to do what i originally intended which was this.



Im starting out with 6KW of panels, this isn’t likely to change due to space limitations

Im looking at this inverter because it allows parallel configuration of up to 10 units, im starting with 1 and aiming for 3 eventually depending on peak load after the pump is fitted.

[https://www.ginlong.com/energy.../s5_eo1p_4-5k_48_en.html](https://www.ginlong.com/energy.../s5_eo1p_4-5k_48_en.html).

And a 16s 48v lipo battery with this BMS.

[https://www.fogstar.co.uk/.../jbd-bms-for-lifepo4-with...](https://www.fogstar.co.uk/.../jbd-bms-for-lifepo4-with...)

Its my intention to increase the battery/inverter side of this with 2 more banks that will all run in parallel, The idea being to catch and use every photon that’s there and charge the banks on off peak elastictrickery to use during peak.

Looks like the inverter that i picked is no good because its not grid tied, and parallel hybrids are not available. does anyone have any idea how to do this?

Parallel hybrids not available? I can parallel up to 6 MPP LVX6048WP's, which can also be grid tied. Up to 36KW.
I will be using my existing grid tie SMA inverters to charge the batteries (70KW of Seplos DIY kits) during the day, and using the MPP's at night. Once I get an additional 24 x 430w panels, I will go totally off grid.

 

[Markvk]

Thanks for that, Yes i was told that parallel inverters are not available... but ive since found these, which will do what i need, they are totally scable, im finally seeing some light at the end of the tunnel.

theres a lot of miss information out there.

8kw Hybrid Inverter | Sunsynk

www.sunsynk.org

 

[Sanwizard]

Thanks for that, Yes i was told that parallel inverters are not available... but ive since found these, which will do what i need, they are totally scable, im finally seeing some light at the end of the tunnel.

theres a lot of miss information out there.

8kw Hybrid Inverter | Sunsynk

www.sunsynk.org

Cool. Those look like competition for Sol-ark, as they are also made by Deye! Great to have another source to force price competition! Capitalism at its finest lowers costs for all.

 

[Markvk]

Cool. Those look like competition for Sol-ark, as they are also made by Deye! Great to have another source to force price competition! Capitalism at its finest lowers costs for all.

Hi, i notice that you have the Seplos DIY kits what AH are they? are they any good is the 600 for the kit worth it? and do you know what the sustained max discharge rate is per pack?

TIA

 

[Sanwizard]

Hi, i notice that you have the Seplos DIY kits what AH are they any good is the 600 for the kit worth it? and do you know what the sustained max discharge rate is per pack?

I have both the 135ah and 280ah Mason kits. I bought the 135ah kits, which included the cells, for $1000 each when they first came out during the initial sale. (Now $2150) The 280ah kits were $400 each then also, but the 200ah BMS was seperate. (I think @sergea from this forum paid to have them developed with seplos.)

The 135ah kits come with the 100ah BMS, so only up to 100amps discharge.

The 280ah kits come with the 200amp seplos BMS, so the discharge rate is adjustable based on your settings. I set mine to 100amps, since I have 7 Mason batteries in parallel.

For the build quality and the money I spent, I am very happy with the purchase. Andy from OffGridGarage youtube channel is providing feedback to Seplos to improve their product, including packaging, and they seem to be listening. Their latest E Series BMS is much better from a comms standpoint vs the older CAN only I have. I am hoping they listen to Andy and add active cell balancing as well in the near future, just like the JK/Heltec BMS has.

So in summary, yeah, the kit is worth it.

 

[Markvk]

Ok thats great information thanks. Ive watched the entire playlist on the battery 2 build of Andy's im about to start on version 3 but i was concerned about the BMS, but if they do a kit where you can pick you own BMS that might work.
Im surprised that a 280AH bank is capable of 100Ah sustainable discharge rate! Ive soo much to learn still.

Where abouts in the world are you?

 

[Sanwizard]

Ok thats great information thanks. Ive watched the entire playlist on the battery 2 build of Andy's im about to start on version 3 but i was concerned about the BMS, but if they do a kit where you can pick you own BMS that might work.
Im surprised that a 280AH bank is capable of 100Ah sustainable discharge rate! Ive soo much to learn still.

Where abouts in the world are you?

This may help. Its the 200amp BMS manual.

Seplos 48v 200A 8S-16S BMS - Please read this manual carefully before operating and retain it for - Studocu

Share free summaries, lecture notes, exam prep and more!!

www.studocu.com

 

[Markvk]

This may help. Its the 200amp BMS manual.

Seplos 48v 200A 8S-16S BMS - Please read this manual carefully before operating and retain it for - Studocu

Share free summaries, lecture notes, exam prep and more!!

www.studocu.com

Thanks for that, im just looking at the seplos site now, i notice that you commented about a bus bar system, at least i think it was you. So looking into it now. I wont be ready to buy for a few months yet so fingers crossed for the active balancing.

 

[Sanwizard]

Thanks for that, im just looking at the seplos site now, i notice that you commented about a bus bar system, at least i think it was you. So looking into it now. I wont be ready to buy for a few months yet so fingers crossed for the active balancing.

Yup, they have a system called JASSN which I bought, but cannot use since it only supports 6 batteries, and I have 7. Comes with nice breakers.

空白页

 

[Markvk]

Yup, they have a system called JASSN which I bought, but cannot use since it only supports 6 batteries, and I have 7. Comes with nice breakers.

空白页

Are you in the UK, if so do you know what the import duties are?

 

[Sanwizard]

Are you in the UK, if so do you know what the import duties are?

I am in the US. I did not pay any duty. Mine was $100 flat rate plus about $40 shipping, but that was late 2021.