Multiple banks multiple bms ??

[Jlibrada]

Hello new here, Im changing from lead acid to Lipo4 3.2v 280 ah batteries for a total of 16s 3.2v 280 48v , Im planing to have two banks connected in parallel 48v 560ah total ,( redundancy) I will like to keep the banks separate but will like to monitor each 3.2v battery 16s , by Bluetooth
I will need two BMS , 16s 48v ?
How I can monitor all the batteries?
Can I have two bms to a single bt device ( computer / phone ) ?

 

[Gauranga108]

I am trying to do the exact same and asof now can't find a bms on alibaba that supports parallel banks. I hope someone can chime in with bms that can handle this that is reasonably priced. I have heard the barium can do it but its very expensive ?.

 

[MisterSandals]

I have heard the barium can do it but its very expensive ?.

Barium will definitely give you that facial expression.

 

[Gauranga108]

Lol darn auto correct.. batrium but barium I am sure will do the same

 

[newbostonconst]

Cells in parallel are just one big cell....they parallel multiple cylindrical cells all the time....

Just need to be sure it carries the current you want for both balancing and total battery current.

Should also be able to put multiple BMS in parallel….

I think I would parallel each cell and series them after that rather then having 2 series packs paralleled....I am not a expert though...IMHO

 

[upnorthandpersonal]

I will need two BMS , 16s 48v ?
How I can monitor all the batteries?
Can I have two bms to a single bt device ( computer / phone ) ?

That's what I run, two BMS per 16 cell battery (2 more this year). I'm using the Heltec/JK BMS and they just show up as different devices so you can monitor them both from the same app.

 

[ArthurEld]

I will use 4 BMSs with my four 48V batteries made of 280Ah EVE cells.
Three more BMSs will be here in a week or two.
I'll find out how well balanced the four batteries will stay.

 

[Gauranga108]

I am not an expert but from what I have taken from others on this forum there will be issues even if you run the two bms separate of each other. Can anyone clarify if I have taken the information wrong or if there are issues to be had, what are they and what are if there is any, solutions.

 

[Gauranga108]

Again in referencing 16s2p where the two separate packs with there own bms are then paralleled after the bms at bus bar locations for both pos and negative.

 

[HRTKD]

I am not an expert but from what I have taken from others on this forum there will be issues even if you run the two bms separate of each other. Can anyone clarify if I have taken the information wrong or if there are issues to be had, what are they and what are if there is any, solutions.

I have 4s2p, not 16s2p. My parallel setup works fine. Please list the issues you're concerned about.

 

[Gauranga108]

I was told in the case of a low temp disconnect or any shut down of one of the bms then the other would take the entire load be it discharging or charging. That being said if the system is designed so that each individual bms of each pack could handle your amp loads of charge and discharge even upon shut down of the other then I guess you should be fine?

 

[ArthurEld]

I was told in the case of a low temp disconnect or any shut down of one of the bms then the other would take the entire load be it discharging or charging. That being said if the system is designed so that each individual bms of each pack could handle your amp loads of charge and discharge even upon shut down of the other then I guess you should be fine?

Yes, build it to work if one battery goes down.

 

[HRTKD]

I was told in the case of a low temp disconnect or any shut down of one of the bms then the other would take the entire load be it discharging or charging. That being said if the system is designed so that each individual bms of each pack could handle your amp loads of charge and discharge even upon shut down of the other then I guess you should be fine?

In the case of low temperature disconnect, charge stops but discharge still works. However, if you've let your batteries get THAT cold, you have other problems that need manual intervention.

I believe the general recommendation is not to exceed .5C charge rate. For my 280 Ah batteries that would be 140 amps. None of the charge sources I have, even if they were all active, could come close to going over 140 amps. Chargers with very high ratings - let's say over 80 amps - are perhaps the exception, not the rule and are quite expensive. Either way, the BMS has the ability to cut off the charger should the charge rate exceed what the BMS is configured to accept.

 

[Gauranga108]

 

[Gauranga108]

Would this be battery bank setup be sufficient for 48v system? What you think

 

[Gauranga108]

Also I showed a similar setup to daly electronics rep on alibaba and she said daly can't to parallel or series and it would work? Should I just ignore this. So in this specific setup would two 300 amp daly bms be sufficient as if I am running at .5 c max load for charging or discharge would be 136amps for these 272 lishen cells.or eve equivalent.

 

[Gauranga108]

Correction Sorry she said it would not work

 

[Gauranga108]

If one bms stops or starts up before the other then one 300amp bms would take the entire load fine correct?

 

[Gauranga108]

Any need with this setup for additional shunt or relats breakers etc?

 

[HRTKD]

Many other BMS have no problem operating in a parallel situation like this. If Daly is such a poor BMS that it can't do it, then pick a different company.

With regard to your drawing, the monitoring shunt should be placed between the BMS and the negative bus bar. I have both my BMS negative cables going directly into the battery side of my shunt.

There should be a fuse, or fuses,between the battery and the positive bus bar.