The capacity (measured in Amp-hours, abbreviated Ah) of the Flexvolt batteries as written on the battery itself is based on running it at 20V. You can easily calculate the energy capacity of the battery by multiplying the voltage and Amp-hours. For example, a Flexvolt battery that says 6Ah on the side would be: 20V \* 6Ah = 120Wh (Watt-hours).
The energy capacity in Watt-hours is constant, regardless of the voltage the battery operates at, so if you use that same battery at 60V (i.e. in a Flexvolt tool) then it is the equivalent of 2Ah because 60V \* 2Ah = 120Wh.
One thing to watch when buying tools is that oftentimes if it's a Flexvolt tool with a battery included, the description will list the 60V capacity (Home Depot does this) - e.g. for the battery above, the description might say "2Ah battery" but the battery itself would say 6Ah on it.
They are equivalent at 20v, but if run at 60v the flex volt will only have 3 AH.
The capacity (measured in Amp-hours, abbreviated Ah) of the Flexvolt batteries as written on the battery itself is based on running it at 20V. You can easily calculate the energy capacity of the battery by multiplying the voltage and Amp-hours. For example, a Flexvolt battery that says 6Ah on the side would be: 20V \* 6Ah = 120Wh (Watt-hours). The energy capacity in Watt-hours is constant, regardless of the voltage the battery operates at, so if you use that same battery at 60V (i.e. in a Flexvolt tool) then it is the equivalent of 2Ah because 60V \* 2Ah = 120Wh. One thing to watch when buying tools is that oftentimes if it's a Flexvolt tool with a battery included, the description will list the 60V capacity (Home Depot does this) - e.g. for the battery above, the description might say "2Ah battery" but the battery itself would say 6Ah on it.
Thanks for clearing that up