I have a 2P8S DIY build question?

I am wondering if my plan is all right. I want to use a 16 cell Luyuan 280A diy battery box, and thinking about a 24v 2P8S configuration, because I doubt 2 BMS's will fit inside of the box. I will be pulling 300A maximum. Will this work alright?

OK, just to be clear.
You want to use a 16S Case, but configure the cells into a 2p8s for a 24V/560AH battery pack, with a Max output of 300A.
300A Continuous or just for surge handling ?

Yes, you can use a 16S Case and setup the cells in 2P8S but the Cross BusBar will have to be sorted.
You can use 1 BMS to manage that, you just wire the sense leads as per a regular 8S keeping in mind that each lead will be looking at 2 cells.
Generally, after 200A Continuous, a Relay/Contactor based BMS is used to handle that amperage, as FETS don;t do so well.
Current JKBMS for example handle up to 200A Continous but can take up to 300A surge.

A NOTE ! If you build 2x 24V/280AH with it's own BMS, you divide both Discharge & Charge and get fault tolerance should one pack shutdown the 2nd keeps going. In general, it's not recommended to set LSP cells in parallel unless they are truly Matched & Batched because things do happen.

Hope it helps, Good Luck

Steve_S said:

OK, just to be clear.
You want to use a 16S Case, but configure the cells into a 2p8s for a 24V/560AH battery pack, with a Max output of 300A.
300A Continuous or just for surge handling ?

Yes, you can use a 16S Case and setup the cells in 2P8S but the Cross BusBar will have to be sorted.
You can use 1 BMS to manage that, you just wire the sense leads as per a regular 8S keeping in mind that each lead will be looking at 2 cells.
Generally, after 200A Continuous, a Relay/Contactor based BMS is used to handle that amperage, as FETS don;t do so well.
Current JKBMS for example handle up to 200A Continous but can take up to 300A surge.

A NOTE ! If you build 2x 24V/280AH with it's own BMS, you divide both Discharge & Charge and get fault tolerance should one pack shutdown the 2nd keeps going. In general, it's not recommended to set LSP cells in parallel unless they are truly Matched & Batched because things do happen.

Hope it helps, Good Luck

Click to expand...

Yes thats the plan, if I could fit 2 BMS's in the box, I'd rather go with a parallel configuration. I will probably buy a second BMS as a back up, if there's not room for it.

Steve_S said:

OK, just to be clear.
You want to use a 16S Case, but configure the cells into a 2p8s for a 24V/560AH battery pack, with a Max output of 300A.
300A Continuous or just for surge handling ?

Yes, you can use a 16S Case and setup the cells in 2P8S but the Cross BusBar will have to be sorted.
You can use 1 BMS to manage that, you just wire the sense leads as per a regular 8S keeping in mind that each lead will be looking at 2 cells.
Generally, after 200A Continuous, a Relay/Contactor based BMS is used to handle that amperage, as FETS don;t do so well.
Current JKBMS for example handle up to 200A Continous but can take up to 300A surge.

A NOTE ! If you build 2x 24V/280AH with it's own BMS, you divide both Discharge & Charge and get fault tolerance should one pack shutdown the 2nd keeps going. In general, it's not recommended to set LSP cells in parallel unless they are truly Matched & Batched because things do happen.

Hope it helps, Good Luck

Click to expand...

So it looks like I'll be under 170A without surge, so should be ok without relays. If I did go the single BMS rout, should I have any concerns with cells going out of balance. I wish I had more room, I'd build 2 seperate 8S batteries, but my RV will only fit the 16c box. By the way thank you Steve for the above reply, been a while since reeding about batteries and such.

One more question, is there any preferance towards JK, Seplos, or JBD BMS's

For me, JK has been good & solid and the new Inverter Edition BMS' answers several needs & wants beyond the previous versions. They are flash updateable to stay current (many are not) and they are being enhanced & updated regularly. I have been using JK 150A & 200A BMS' for quite some time, have a lot of them out there to boot. I am now redoing my own home bank with the new Steel cases & JK Inverter BMS' so all 6 packs will be pretty much identical 280AH configurations and connected.

If you have Grade A cells which are properly matched, you should have no issues with the 2P8S setup and you are aware of the limitations for doing so.

I am not a Power Hungry user.... hell I gave away my AC system cause I built my home in such a way that it is not needed at all... It can be 40C/104F outside and the house itself never goes above 28C/82F. I rarely ever pull more than 125A off my bank, even IF the compressor is pushing to cutoff under load (that's a stress tester to be sure, like the MIG Welder).