Help Designing 6000Watt System

[CompleteSI]

Hey all!! I purchased:
(16) 280 AH LiFePO4 packs that I am running series parallel to get 24volts.
ANT 100A BMS with 300A Peak.
AIMs 6000 Watt inverter (PICOGLF6024120ULC) with 120Volt Out and 120Volt 60Amp Charger.
Victron 50 MPPT Solar Charger
800 Watts Of Renogy Solar Panels
Simarine Pico Monitor

From watching all the videos it seems like I should run everything through the ANT BMS. It is only 100Amps so there is no way it can power the inverter. I found the video where Will uses a Relay to trip a Victron Battery Protect with the inverter connected to that but found where he says not to use that anymore. Also those are only 250 Amps and my calcs say Ill be pushing 300-400 Amps. Most system diagrams I find don't seem to be as large or they don't seem to us a BMS.

Am I supposed to buy multiple BMS's and connect Parallel or is there a better alternative? Also if I don't have the inverter connected to the BMS then the Charger Just goes direct to the battery as well.

Thanks for any help, I do high end large scale Audio/Video/Automation for a living and am happy to return any help with knowledge in that area if anyone needs it.

Jon

 

[Rocketman]

There are two flavors of bms’s. Ones that switch the power themselves -like Overkill, Daly and ANT. They are cheaper ones. The second flavor use a contactor (relay) to switch - like Batrium,Rec-bms and Orion jr. They are more expensive- especially with all the added components.

some people will split the battery and have two Bms’s.
One way you can get a cheaper bms to control a large inverter load is to connect the inverter to a contactor that connects directly to the battery - then the bms controls the contactor.

Examples of a contactor Tyco EV200AAANA-(that one is 12v - they make a 24v one) Gigavac also makes them.

 

[CompleteSI]

There are two flavors of bms’s. Ones that switch the power themselves -like Overkill, Daly and ANT. They are cheaper ones. The second flavor use a contactor (relay) to switch - like Batrium,Rec-bms and Orion jr. They are more expensive- especially with all the added components.

some people will split the battery and have two Bms’s.
One way you can get a cheaper bms to control a large inverter load is to connect the inverter to a contactor that connects directly to the battery - then the bms controls the contactor.

Examples of a contactor Tyco EV200AAANA-(that one is 12v - they make a 24v one) Gigavac also makes them.

Thanks for the reply and Info, So can I use the Contactor and connect the solenoid negative to the negative on the ANT BMS like Will did on his video so if the BMS shuts down it kills the contactor and releases? Or will the ANT not balance the cells if not being charged from it? I could connect the solar charger through the BMS and keep the Inverter/Charger connected to the contactor. Would that be alright?

 

[John Frum]

6000 ac watts * 1.5 low frequency surge factor / 24 volts low cutoff = 375 dc amps
375 dc amps * 1.25 fuse factor = 468.75 fuse amps.
That is a lot of current.
Is 48 volts an option?

 

[Rocketman]

Does your bms keep track of battery capacity? (How many ah are in the battery?). If it does that will be inaccurate.
Yes run everything else through the bms. Loads, solar, etc. It may make battery monitoring a challenge.

The contactor’s small negative (coil wire) will attach to the bms- but the big wire from the inverter will bypass the bms and connect directly on the battery. Does that make sense?

Because writing things down - especially circuits - forces us to think through everything exactly, I would highly recommend making a drawing and putting all your components on it. - include wires, fuses, everything. Research each one to make sure it is exactly right for you.

You are the system engineer- it is your job to make sure everything works together to accomplish your requirements.

There are lots of different equipment you can buy - sometimes a more expensive piece will be better in the long run or have better features (reporting). Take the time to understand all your equipment BEFORE buying.

On solar panels - look for used ones (locally). For example Suntan solar is selling used 250watt panels for $50. You may find local deals that don’t need to be shipped a much better deal. In my area I can buy new blemished panels from the solar install companies for a discount.

 

[CompleteSI]

6000 ac watts * 1.5 low frequency surge factor / 24 volts low cutoff = 375 dc amps
375 dc amps * 1.25 fuse factor = 468.75 fuse amps.
That is a lot of current.
Is 48 volts an option?

I guess I could, I already have the inverter and other pieces. I am installing in a mobile application so it was much easier to use 24 Volts. I have a 26 volt Alternator I found and 12 Volt Solar Panels I was going to run in series/parallel.

 

[John Frum]

Also the inverter you spec is 120/240VAC split phase.
Is that what you require?

 

[CompleteSI]

Also the inverter you spec is 120/240VAC split phase.
Is that what you require?

No, the one I purchased is single phase 120VAC. Maybe I wrote down the wrong number when I posted.

 

[Hedges]

I guess I could, I already have the inverter and other pieces. I am installing in a mobile application so it was much easier to use 24 Volts. I have a 26 volt Alternator I found and 12 Volt Solar Panels I was going to run in series/parallel.

Since you have the cells for 1 string 48V or 2 string 24V battery, you could add a second BMS. Each would then allow 100A continuous, 300A surge.
200A x 24V = 4800W continuous (more at higher voltage, less given inefficiency)
16 cells x 280 Ah x 3.7V = 16 kWh.
You can have about 3.5 hours at 4800W (or 7 hours at 2400W)
What is your highest expected AC load?

 

[John Frum]

No, the one I purchased is single phase 120VAC. Maybe I wrote down the wrong number when I posted.

You are probably correct.
The manual I was looking at is common across models.
On the other hand I don't think I've ever seen a 6000 watt low frequency inverter that is 120VAC.

 

[CompleteSI]

Since you have the cells for 1 string 48V or 2 string 24V battery, you could add a second BMS. Each would then allow 100A continuous, 300A surge.
200A x 24V = 4800W continuous (more at higher voltage, less given inefficiency)
16 cells x 280 Ah x 3.7V = 16 kWh.
You can have about 3.5 hours at 4800W (or 7 hours at 2400W)
What is your highest expected AC load?

I have:
Dometic AC 1382 Watts
Induction Cook Top (1) 1800 Watts
Induction Cook Top (2) 1800 Watts
Microwave 1500 Watts
Misc Outlets 850 Watts
Water Heater 1200 Watts

Everything else is 24v or 12v.

 

[Hedges]

I have:
Dometic AC 1382 Watts
Induction Cook Top (1) 1800 Watts
Induction Cook Top (2) 1800 Watts
Microwave 1500 Watts
Misc Outlets 850 Watts
Water Heater 1200 Watts

Everything else is 24v or 12v.

If you can arrange to only run one heating/cooling load at a time, you'll be fine with single BMS.
To run more, dual BMS or 48V, and have to see how long the 300A peak is good for. Maybe an AC breaker coordinated to trip before BMS disconnects would "remind" you you're drawing too much.
Otherwise, might want a way to bypass the relay/FET of BMS. It's signal could be used to turn off inverter, or control an AC relay to connect/shed loads. Or drive a bigger relay.

 

[Q-Dog]

I would get 2 identical BMSs and build 2 identical 24 volt battery packs, then parallel the packs.

 

[CompleteSI]

So I found a Daly BMS that can handle 500amps at 24volts. Anyone familiar with these or have any thoughts?
Thanks,