Do parallel batteries increase continuous discharge rate? Connector upgrade required?

Patel said:

Hello,

I am thinking about buying a battery, it is 48v and max continuous discharge current of 150 amps.

My question is, if I parallel 2 of these batteries, does it increase the max continuous discharge current to 300 amps?

Also, the stock connector which is included with the battery is the Anderson 150 amp connector, if I am paralleling 2 of these batteries, do I need to use the Anderson 350 cable to connect to the inverter and between the batteries?

Thank you very much

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rhino said:

And you typically would not want to max out the allowable discharge rate so if you truly need 300A it would be better to have 3 so you are theoretically only pulling maximum of 100A pe

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Joehebbo said:

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TacomaJoe said:

Your system with 4 100Ah batteries in parallel can be treated as a single 400Ah battery. Your charge/discharge currents will split evenly between each battery, so if you are pulling 200A for the inverter, each battery BMS only passes 50A. The trick here is to stay away from the top or bottom. If you were pulling the 200A and two batteries cut out for low voltage disconnect, the remaining two pick up the load and now would be passing 100A each. When one of those two cuts out the BMS will have an overcurrent trip.

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TacomaJoe said:

so what do you advise put max discharge and max charge for such 400 ah rack ?

Each BMS has its over current settings. My 150A JBD BMS is set for 160A for 10 seconds (factory default). Those limits protect the BMS and no need to alter them. In my 400A bank example, if each BMS can handle 100A, in theory the bank can handle 400A of charge or discharge.

In my real life system, I have 3 280Ah 12V batteries in parallel to a 2000W inverter. On the charging side PDI9160L converter and an Epever SCC at 40A. I get nowhere near any of the limits for my equipment and one battery can pretty much serve the loads.

In a big bank, the wires from each battery need to be sized/fused for the BMS limit (100A) to the buss bar. From the buss bar to the inverter needs to be sized for the total of the 4 batteries, thus 400A rated wire.

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TacomaJoe said:

so what do you advise put max discharge and max charge for such 400 ah rack ?

Each BMS has its over current settings. My 150A JBD BMS is set for 160A for 10 seconds (factory default). Those limits protect the BMS and no need to alter them. In my 400A bank example, if each BMS can handle 100A, in theory the bank can handle 400A of charge or discharge.

In my real life system, I have 3 280Ah 12V batteries in parallel to a 2000W inverter. On the charging side PDI9160L converter and an Epever SCC at 40A. I get nowhere near any of the limits for my equipment and one battery can pretty much serve the loads.

In a big bank, the wires from each battery need to be sized/fused for the BMS limit (100A) to the buss bar. From the buss bar to the inverter needs to be sized for the total of the 4 batteries, thus 400A rated wire.

Click to expand...

rhino said:

And you typically would not want to max out the allowable discharge rate so if you truly need 300A it would be better to have 3 so you are theoretically only pulling maximum of 100A per battery.

Click to expand...