Can you mix battery brands in one bank

Two 48V LiFePO4 packs from different manufacturers will happily sit in parallel and pass current. The problem starts one layer up, where two BMS units are each making decisions about a bank they can only partly see.

Voltage windows are the first thing to check and the easiest to get right. A pack that protects at 56 volts sitting beside one that charges to 58.4 will disconnect first, every cycle, and the remaining pack then absorbs the whole charge current on its own.

Charge and discharge limits do not average

A bank made of a 100 amp pack and a 50 amp pack does not accept 150 amps evenly. Current divides by impedance, not by rating, so the healthier or lower resistance pack takes more than its share and can exceed its own limit while the bank total looks safe.

Age has the same effect. Adding a new pack to a bank that is three years old creates exactly this imbalance, which is why manufacturers tell you to add capacity in matched sets or not at all.

The comms layer is where it really breaks

Closed loop expects one master reporting for the bank. Two brands means two protocol implementations, usually two different dialects, and inverters that accept only one battery identity on the bus. The common outcome is that one pack reports, the other is invisible, and the inverter makes decisions for a bank it is measuring half of.

Running mixed banks open loop, with hand set conservative limits, is the configuration that actually works. You give up state of charge accuracy and BMS requested current limiting. In exchange, no unit is pretending to speak for hardware it cannot see.

The practical rule

Same brand and same model for one bank. If you must mix, match the voltage windows first, size the charge limit to the weakest pack, and run open loop. Then keep a shunt monitor on the bank so you are measuring rather than trusting.

If you are expanding a bank

Matching an existing pack is the cheapest way to avoid the problems above.

48V rack batteries Bank shunt monitors

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This note describes behaviour that follows from published voltage and current limits. No manufacturer publishes a tested mixed brand configuration, so any mixed bank is unverified by definition.