diy solar

diy solar

BMS for 280ah 16s 48v Lifepo4 connected to Growatt 5000es

JoshVannette

New Member
Joined
Jun 7, 2022
Messages
31
Good morning working on picking up a 48v BMS for my 280ah eve cells. Any recommendations, was leaning towards overkill 100amp 48v 16s. But don't really need low temp protection for my setup. Thoughts on the best option and how many amps would be best for this setup. I'm running 2 x growatt 5000es with an auto transformer and 12kw of solar.

Second question is which circuit breaker should I place between my battery and the controller for this build?

Thanks,
Josh
 
Good morning working on picking up a 48v BMS for my 280ah eve cells. Any recommendations, was leaning towards overkill 100amp 48v 16s. But don't really need low temp protection for my setup. Thoughts on the best option and how many amps would be best for this setup. I'm running 2 x growatt 5000es with an auto transformer and 12kw of solar.

Second question is which circuit breaker should I place between my battery and the controller for this build?

Thanks,
Josh
5000 ac watts / .85 inverter efficiency factor / 48 volts low cutoff = 122.549019608 dc amps
122.549019608 dc amps * 2 inverters = 245.098039216 service amps
245.098039216 service amps / .8 fuse headroom = 306.37254902 fault amps

You need BMS capacity of at least 245 continuous amps.
 
Also drawing more than 140 amps continous from a 280 amp hour battery made of eves cells causes ion starvation which is less than ideal.
 
Also drawing more than 140 amps continous from a 280 amp hour battery made of eves cells causes ion starvation which is less than ideal.

5000 ac watts / .85 inverter efficiency factor / 48 volts low cutoff = 122.549019608 dc amps
122.549019608 dc amps * 2 inverters = 245.098039216 service amps
245.098039216 service amps / .8 fuse headroom = 306.37254902 fault amps

You need BMS capacity of at least 245 continuous amps.
I have two 100ah eg4s setup to one inverter currently, and planned to connect this 3rd battery to my second inverter. Does this change the calculation at all? And would there be any issue going with a lower amp BMS such as the overkill 48v 100amp?
 
I have two 100ah eg4s setup to one inverter currently, and planned to connect this 3rd battery to my second inverter. Does this change the calculation at all? And would there be any issue going with a lower amp BMS such as the overkill 48v 100amp?
Why not connect all the batteries and all the inverters to the same busbars?
Assuming the eg4 batteries are 48 volts you would have 300 amps continous which is more than enough to run the 2 inverters.
 
Why not connect all the batteries and all the inverters to the same busbars?
Assuming the eg4 batteries are 48 volts you would have 300 amps continous which is more than enough to run the 2 inverters.
Great idea, they are all 48v. Would it still be best to look for a more powerful BMS for the diy battery or just go with a daly or overkill
 
Great idea, they are all 48v. Would it still be best to look for a more powerful BMS for the diy battery or just go with a daly or overkill
Each of your BMS's can deliver 100 amps continous and you only need 245 amps(see math in previous post) so you are all set.
I prefer the Overkill BMS to the Daly because it has more balance capacity.
 
I just started using the Jikong (JK ) BMS. 200 amp, 2A balancer. Same eve 280 A batteries. I have two 6500's but I will never draw that many amps at once. I used a 175 amp DC breaker off Ebay. If you use a JK, get the small lcd box for $20, it will keep you from having to get it to over 54v to start up. I ordered together from Hankzor on Aliexpress.
 
I have two 100ah eg4s setup to one inverter currently, and planned to connect this 3rd battery to my second inverter. Does this change the calculation at all? And would there be any issue going with a lower amp BMS such as the overkill 48v 100amp?
Thank you!
 
Back
Top