There is no one-size-fits-all answer to this question. The ideal number of batteries depends on the type of work being carried out and the tools being used.
Thanks to the high energy density and extremely short charge times of the ALLPRO Battery System, you don't have to keep a separate battery for each power tool. In practice, a two-person landscaping team has found that having three batteries and a high-speed charger works well. While two batteries are in use in the power tools, the third can be on charge, and with the AL 1802 MO high-speed charger it can reach 80% capacity in just 9 minutes*.
* Time to reach 80% charge at ambient/battery temperatures of 25-40°C in combination with AL 1802 MO. Valid for ALLPRO batteries AP 100.0 P, AP 200.0 P and AP 300.0 P(C).