12S 2P BMS?

[Catastrofe]

I'm not sure if the order of "12S" and "2P" matters in my title, but here's the scenario. Two 6 cell Yinlong 40AH LTO cylindrical packs connected in parallel to yield 80AH at ~13.8V. I think I need a 12S BMS. . .correct? Any links to an affordable and reliable unit?

Also, is it possible to start off with just a single pack using a 12S BMS, and add a second pack in parallel at a later point? Or would I need to use a 6S BMS initially, then upgrade to a 12S if a second pack is added?

 

[Supervstech]

No, you need a 6s BMS.

 

[Supervstech]

LTI have 2.3v per cell, so, a 6s-2p configuration yields 13.8v.

 

[Supervstech]

12s gives you 27.6v

 

[Supervstech]

The BMS needs to match the final voltage.

if you wish to monitor every cell, you need a separate BMS for each 6s pack.

 

[Catastrofe]

Thanks. So to make sure I understand....

There will be two 6S packs connected in parallel. Each pack needs its own 6S BMS even though they’re connected?

 

[Steve_S]

6 cell Yinlong 40AH LTO cylindrical packs

Each pack = one battery = 1 BMS per battery and in this config that is S6 as Supervstech pointed out. Be careful that the BMS you choose supports LTO battery type, not all do and that can be most unpleasant. Also some BMS' will not allow for parallel or series connection, so if in doubt, verify with the vendor / manufacturer first, would not want to get stuck with the wrong one.

 

[Catastrofe]

Thanks. Still learning. . .I appreciate the help. Now I need to find an appropriate BMS.

 

[Steve_S]

c

Thanks. Still learning. . .I appreciate the help. Now I need to find an appropriate BMS.

Check my signature

 

[Craig]

Thanks. Still learning. . .I appreciate the help. Now I need to find an appropriate BMS.

Yes I use the chargey BMS for my LTO cells . I would recommend if you wish to start with 6 and add on you build the 6 pack first then break it down and add the next 6 in 2p6s configuration to save on the bms.

If you want some cells to play with let me know I have some that are around 35-38 ah Im willing to sell for a song they work fine just do not reach there listed 40Ah and its too costly to return them to china.

 

[Catastrofe]

c

Check my signature

Looks like just the ticket!