A battery’s power is how fast it can be charged or discharged. You can find the related information in the product datasheet.
For example, in the datasheet of Sixclocks-BESS3, the battery max. charging/discharging current is 1C which means it can discharge all its usable energy in 1 hour.
As for another battery of Sixclocks-BESS288100, the max. charging/discharging current is 0.5C, which means it can discharge all its usable energy in 2 hours. (Make the max. charging/discharging current divide 1, you will get the charging/discharging time; or you can simply refer to the chart below)
A higher power home battery system doesn’t mean it’s better than a lower one as your own household’s energy usage needs will determine how much power you require from a solar battery and the best energy storage solution for you.