High voltage bms

[maarkmohamed]

Hello anyone have a idea where I can find a compact high voltage bms? Looking for something around 35-40s. And obviously for a ebike battery it needs to be compact. I'm leaning towards something that will use a relay. What I have found is heltec makes one, but doesn't have any Bluetooth to view the bms, or any way of connecting to it. Daly makes one but no active balancing.

 

[TrotterBob]

The Extreme Bull K6 uses a 32s controller but thats for a dual motor setup.

Some links I found. Dunno if any of this might be useful. Also doing a search for 32s speed controller BMS seems to yield interesting results.

ANT 10S-32S 150A-300A Li-ion LiFePo4 Smart BMS w/Balanced Bulid in Bluetooth | eBay

Support 10S~32S of Li-ion, LiFePo4, and Lithium Titanate. 300A version: peak current 300A, continuous current 120A. Then start from the black wire and start from the first white wire from right to left to the first cell, second cell, third cell of the battery and so on, and connect to the...

www.ebay.com

 

[eee291]

I've also found this Daly BMS that goes to 48s, It's pretty expensive.

https://www.aliexpress.com/item/1005004514591565.html

 

[maarkmohamed]

The Extreme Bull K6 uses a 32s controller but thats for a dual motor setup.

Some links I found. Dunno if any of this might be useful. Also doing a search for 32s speed controller BMS seems to yield interesting results.

ANT 10S-32S 150A-300A Li-ion LiFePo4 Smart BMS w/Balanced Bulid in Bluetooth | eBay

Support 10S~32S of Li-ion, LiFePo4, and Lithium Titanate. 300A version: peak current 300A, continuous current 120A. Then start from the black wire and start from the first white wire from right to left to the first cell, second cell, third cell of the battery and so on, and connect to the...

www.ebay.com

Thanks for sharing this I've seen this one before and I'll keep it in mind. Wondering if there is anything of higher voltage.

 

[maarkmohamed]

I've also found this Daly BMS that goes to 48s, It's pretty expensive.

https://www.aliexpress.com/item/1005004514591565.html

This was the daly bms I was referring to. My concern with this is that daly doesn't have that good of reputation, and this one does not have active balancing if I'm not mistaken.

 

[eee291]

I don't know why active balance is so important, but this BMS seems to have it.

 

[floydr]

30mA


Later
floyd

 

[maarkmohamed]

I don't know why active balance is so important, but this BMS seems to have it.

There's active balancing and then there's another kind I forgot what it's called. The active works much better from what I'm hearing/reading from people who have used both.

 

[amberwolf]

If you are going to use a contactor (relay) for pack output control instead of having hte BMS directly controlling the pack output, then you can actually use multiple BMS boards for sections of the pack, and optocouple their control outputs together at a logic board (that you'd have to make, probably easiest with a little Arduino Nano or similar, but can be done with discrete parts) that turn a relay driver on unless any BMS turns it's enable output off. As soon as any of them turn off, the relay driver turns off, disconnecting the output from your system.

But...if I were making a BMS (or using any contactor based BMS), I would not actually let the BMS actually disconnect the pack at all--that I'd leave to the user, but I would have the BMS's enable output instead tell the controller to stop running the motor (easy enough by disabling the throttle and braking inputs), or else reduce the available current it can use to run the motor with (more complicated).

 

[maarkmohamed]

If you are going to use a contactor (relay) for pack output control instead of having hte BMS directly controlling the pack output, then you can actually use multiple BMS boards for sections of the pack, and optocouple their control outputs together at a logic board (that you'd have to make, probably easiest with a little Arduino Nano or similar, but can be done with discrete parts) that turn a relay driver on unless any BMS turns it's enable output off. As soon as any of them turn off, the relay driver turns off, disconnecting the output from your system.

But...if I were making a BMS (or using any contactor based BMS), I would not actually let the BMS actually disconnect the pack at all--that I'd leave to the user, but I would have the BMS's enable output instead tell the controller to stop running the motor (easy enough by disabling the throttle and braking inputs), or else reduce the available current it can use to run the motor with (more complicated).

I see what your saying but that's a bit complex for me to make that kind of bms. If something like that was available ready to buy I would look into it

 

[nbtesh]

I see what your saying but that's a bit complex for me to make that kind of bms. If something like that was available ready to buy I would look into it

Hello Everybody, does anyone have any other suggestions for integrated HVDC BMS?

 

[Hummina Shadeeba]

I got a 36s smart bms from Daly for $216 with shipping. I bypass the bms for discharging. It’s pretty small. Every other bms at that voltage I could find cost at least 3x as much.

 

[amberwolf]

Hello Everybody, does anyone have any other suggestions for integrated HVDC BMS?

What specifically do you need it to do for you?

What chemsitry and number of series cells does it have to handle?

How much current does it have to deal with for charge, and for discharge?

Etc.