You can run your entire Worx Power Share collection of tools on these 20V 2.0 Ah Max Lithium-Ion Batteries. String trimmers and impact drivers, circular saws and lawnmowers, Hydroshots and leaf blowers, the list goes on and on. These batteries are lighter, which makes the tool lighter, and more efficient, than rechargeable batteries based on older designs. Max L-ion batteries don’t wane or drain, and won’t suffer from the memory effect that prevented last generation’s batteries from fully charging as they got older. Plus, they just last longer, so they’ll save you money. You can buy less of them because you can share each one between multiple tools. Cordless tools are much more cost-effective than gas, and you won’t have to worry about getting snagged on a cord. 40V Power Share tools run on these batteries too, you just need two of them (20V + 20V = 40V). They provide gas-like power and performance without all the drawbacks of gasoline: no fumes, no mess, no paying at the pump. Depending on the task, and the tool, these batteries will have different runtimes, but a good rule of thumb is that one 20V 2.0 Ah battery will provide enough charge to power our Worx GT String Trimmer/Edger/Mini-Mower through an average 1/4 acre lawn. These batteries are compatible with the following chargers (not included): WA3742, WA3868 quick charger, WA3875 dual-port charger, WA3878 quick dual-port charger.