When creating a lead-acid battery bank with a higher voltage, like 24 or 48V you will need to connect multiple 12V batteries in series. But there is one problem with connecting batteries in series, and this is that batteries are not electrically identical. They have slight differences in internal resistance.
Flow batteries and other chemistries. These are commonly available in 48V. Multiple batteries can connect in parallel without any issues. Each battery has its own battery management system. Together they will generate a total state of charge value for the whole battery bank. A GX monitoring device is needed in the system.
Here is the guide on how to connect 50kW Hybrid Inverters with Batteries in Parallel. First note - Each 50kW Inverter MUST have it's own HV Battery pack, unlike cases of other hybrid inverter with LV battery, HV battery can only be connected separately to HV hybrid inverters.
Two male MC4 connector for 8 AWG wires. Two female MC4 connector for 8 AWG wires. Up to 3 batteries can be connected to the inverter. If ‘n’ batteries are to be connected to the inverter, then ‘n-1’ connector field kits are required, as detailed in the following table:
Most of the current will therefore travel through the bottom battery. And only a small amount of current will travel through the top battery. The correct way of connecting multiple batteries in parallel is to ensure that the total path of the current in and out of each battery is equal.
When batteries are connected in series, the voltage increases. When batteries are connected in parallel, the capacity increases. When batteries are connected in series/parallel, both the voltage and the capacity increase. Single battery. Two batteries in series. Two batteries in parallel. Four batteries in series/parallel. Four batteries in series.