BMS Size for 560ah 24v 16 cells 8s 8p

[agrrip]

I'm trying to figure out what size BMS to get for my DIY LiFePo4 battery bank. I purchased 16x 3.2v 280ah cells off of aliexpress. I plan on having 8 pairs in parallel and then running those in series for a 560ah 24v setup. I'm just not sure what size BMS to get. I do know that it needs to be an 8s 24v BMS. But, is the Daly 250amp large enough? Or, do I need to go bigger?

 

[snoobler]

Welcome to the forum.

What is the maximum anticipated current?

Have you considered having 2X 8S batteries instead? You have redundancy in case you have a problem with a cell.

 

[HRTKD]

I'm with snoobler. Two batteries is my preference over one with paired cells.

The 8s Overkill Solar 100 amp BMS is a popular choice. If you use two batteries, you get 200 amps of throughput.

 

[agrrip]

Welcome to the forum.

What is the maximum anticipated current?

Have you considered having 2X 8S batteries instead? You have redundancy in case you have a problem with a cell.

Not sure on the current. I haven't purchased all of my electronics yet to do the math. But, figure refrigerator, occasional a/c, led lights, water pump, occasional hair dryer, occasional air fryer, etc.

I have thought about 2 batteries vs 1. Just looking at costs and pairing down where I can. Battery probably shouldn't be that area, lol! If I did 2x 8s batteries, could I get away with a two smaller BMS's? Or, should I stick with 2x 250 amp bms's?

 

[snoobler]

Occasional a/c and water pump are likely your biggest considerations.

What A/C unit?

What pump?

Both of those items likely have substantial surge and will dictate a large current from the battery.

 

[agrrip]

Occasional a/c and water pump are likely your biggest considerations.

What A/C unit?

What pump?

Both of those items likely have substantial surge and will dictate a large current from the battery.

Probably the Mr. Cool 20 Seer 18k btu. The specifications show 20 amps and 230 volts.

I'm also thinking about configuring the cells in 4x 12v batteries and wire them 2s 2p for 24v. My main concern is making sure I get the right size BMS for each. I'm honestly not all that up on how to size a BMS to your system and I can't really find any good videos explaining it.

 

[snoobler]

Ah. Big difference between saying "A/C" vs. "mini-split." Mini-splits don't have surge like "A/C" units. 20A on that unit is over-current protection. It won't ever use close to that.

I wouldn't consider your 2S 2P 12V solution. It's more complicated with less certainty with no added value.

 

[agrrip]

Ah. Big difference between saying "A/C" vs. "mini-split." Mini-splits don't have surge like "A/C" units. 20A on that unit is over-current protection. It won't ever use close to that.

I wouldn't consider your 2S 2P 12V solution. It's more complicated with less certainty with no added value.

Okay, so if I go with the 2 battery solution. Do you think 2 100a BMS's would be sufficient?

 

[snoobler]

I can't answer that without knowing how much current you'll need. That's dictated by the loads and if they have surge.

So, we're pretty much back to my original response in post #2.

 

[Jimmynik1]

I'm trying to figure out what size BMS to get for my DIY LiFePo4 battery bank. I purchased 16x 3.2v 280ah cells off of aliexpress. I plan on having 8 pairs in parallel and then running those in series for a 560ah 24v setup. I'm just not sure what size BMS to get. I do know that it needs to be an 8s 24v BMS. But, is the Daly 250amp large enough? Or, do I need to go bigger?

How did you make out with your build?
Im prepping for the same 16 cell, 8s2p.
Any pics?

 

[agrrip]

I ended up going with 2x Daly 250a BMS's. I did two separate batteries wired in 24v 8s. I'll wire the two batteries in parallel. No pics yet. Still waiting for the BMS's to arrive. It's taking forever!

 

[308andyj]

Much like you and Jimmy, I'll be doing the same setup, so please keep us informed so we can learn from your experience.

 

[agrrip]

Much like you and Jimmy, I'll be doing the same setup, so please keep us informed so we can learn from your experience.

Will do. The BMS's have finally been delivered. Will start building batteries soon.

 

[Danner]

I got the 60v 60a Daly bms and after 5 weeks, it's dead. They're sending me a new one. But now think I should have gotten 100 plus amp