Looking for BMS that support series connection for high voltage battery setup

[da9el84]

Hey guys,

I've finally completed my 3x 12kW Deye inverters with 3x Seplos MASON 280 DIY kits, and I am now looking at the next shiny thing, the Deye SG01HP3 50kW to run our whole installation instead :D
It runs on high voltage batteries (150-800V) and I am wondering if anyone knows of DIY BMS units that support series connection, so I can series connect multiple 48V systems to get the high voltage that this system requires?

 

[sunshine_eggo]

You're likely going to have to go with an EV BMS.

48V BMS in series must be rated to handle the whole bank voltage, and you're not going to find that.

Orion BMS 2 | Orion Li-Ion Battery Management System

• Capable of measuring up to 180 battery cells per unit connected in series based on configuration.
• Up to 2x Remote Cell Tap Expansion Modules can be connected to measure higher voltage battery packs (up to 800vDC max).

 

[Ampster]

I use an Orion and previously used an Emus BMS. Both trace their heritage to EVs which typically have higher voltages and use contactors.

 

[sunshine_eggo]

I use an Orion and previously used an Emus BMS. Both trace their heritage to EVs which typically have higher voyages and use contactors.

I love a high voyage.

 

[stienman]

This should work at least to 350v:

GitHub - stuartpittaway/diyBMSv4: Version 4 of the diyBMS

Version 4 of the diyBMS. Contribute to stuartpittaway/diyBMSv4 development by creating an account on GitHub.

github.com

There are companies that sell assembled and programmed kits and individual parts. It doesn't include shutoff, but it has rules and outputs so you can use contactors to shut the battery down if the pack or individual cell voltages go out of spec. The current monitor is a separate piece as well.

Might be a bit too diy, but it's an option.

 

[stienman]

There's a reasonably active forum for it here:

diyBMS

Do it yourself battery management system for Lithium ion battery packs/cells

community.openenergymonitor.org

 

[da9el84]

You're likely going to have to go with an EV BMS.

48V BMS in series must be rated to handle the whole bank voltage, and you're not going to find that.

Orion BMS 2 | Orion Li-Ion Battery Management System

• Capable of measuring up to 180 battery cells per unit connected in series based on configuration.
• Up to 2x Remote Cell Tap Expansion Modules can be connected to measure higher voltage battery packs (up to 800vDC max).

There are 48V batteries out there with BMS that support series connection, so I figured it also existed in the DIY space, but it's slim pickings here :D

 

[sunshine_eggo]

There are 48V batteries out there with BMS that support series connection, so I figured it also existed in the DIY space, but it's slim pickings here :D

Please link.

 

[da9el84]

Please link.

For example: https://www.deyeess.com/product/se_g5_1_pro

 

[sunshine_eggo]

For example: https://www.deyeess.com/product/se_g5_1_pro

I see no specification indicating those batteries can be placed in series. It indicates up to 64 can be placed in parallel. "Scalability" only references parallel.

 

[da9el84]

I see no specification indicating those batteries can be placed in series. It indicates up to 64 can be placed in parallel. "Scalability" only references parallel.

I know, Deye unfortunately still have a long way to come on their documentation/communication side, but they confirmed multiple times that these can be series connected.

 

[da9el84]

Alright, so it seems the people posting on their facebook isn't the sharpest when it comes to English, so I think what they meant was that there are HV options available too and it's not the ones listed.
Their HV option with 48V battery packs is called BOS-G and comes with a dedicated controller

 

[1.21 Gigawatts]

EV BMS.

i dont think this sounds like a good idea if it cant communicate with HV inverters?

I use an Orion and previously used an Emus BMS. Both trace their heritage to EVs which typically have higher voltages and use contactors.

but does your battery talk to your inverter? Which inverter do you use?

Their HV option with 48V battery packs is called BOS-G and comes with a dedicated controller

Ok will have a look...

 

[sunshine_eggo]

i dont think this sounds like a good idea if it cant communicate with HV inverters?

but does your battery talk to your inverter? Which inverter do you use?


Ok will have a look...

Lots of people have batteries that don't talk to their inverters.

 

[1.21 Gigawatts]

Lots of people have batteries that don't talk to their inverters.

the inverterters ive been looking at wont use the battery unless they can talk to it. (annoying i know)

 

[da9el84]

Lots of people have batteries that don't talk to their inverters.

I think that might be different for HV vs. LV inverters.

 

[1.21 Gigawatts]

i just got quoted $1400 for a system that will do 4x48v in series with a master using heltec equipment. Too expensive Tbh. Still cheaper than batrium at $1700

These HV battery manufactures are surely only paying $350 tops for their BMS. Even though Seplos do DIY 48v kits, they wont sell their HV BMS ?

 

[1.21 Gigawatts]

Edit: nm seller said that BMS wont talk to inverter.

 

[Ampster]

but does your battery talk to your inverter? Which inverter do you use?

No it just uses a contactor in my application. I use a 48 Volt Outback Skybox. The Orion and the Emus cost over $1,000 for a 64 cell BMS. Both are capable of CAN communications and often communicate with the chargers in EVs. I will let @da9el84 figure out if they can communicate with the inverter he is using.

 

[Cheap 4-life]

i just got quoted $1400 for a system that will do 4x48v in series with a master using heltec equipment. Too expensive Tbh. Still cheaper than batrium at $1700

These HV battery manufactures are surely only paying $350 tops for their BMS. Even though Seplos do DIY 48v kits, they wont sell their HV BMS ?

From taking apart multiple EV batteries, it seems like the BMS they use do not actually balance the cells. Usually cells used for EV packs are matched so well that balancing isn’t needed. I think the BMS do have a cell level voltage cutoff using contactors. If cells get out of balance the packs are usually retired to the DIY battery community or the scrap bin