DJC wrote:

Is that really 40v or just a rebranding of 36v

makita don't currently make a 36V battery, their 36V tools use 2x18V
batteries, so it's a reconfiguration of the batteries to higher voltage
(but lower current)

in the same way that
Bosch rebranded 10.8v as 12v?

yes at the same time the marketing dept has convinced them to use the
max. voltage instead of nominal voltage