Heat pumps are not exactly range extenders by design, but are primarily used for the HVAC system, which reduce the use of the battery.
Where as EV’s fitted with resistance heating systems are 100-percent efficient because they convert all of the energy consumed to heat energy. Heat pumps take this one stage further and can produce 3kW of thermal energy for every 1kW of electric energy. If most of your your journey times are under a hour or your only pottering say around town using 5-85% of the battery capacity you are not going really benifit from a heatpump. The other point is, we live in a relatively mild country and would not get anywhere near the benifit as countries like Norway would.
@MickC I can’t see how a heatpump will prolong the battery life, unless you are refering to a few more miles of range!
@BrickTop Heatpumps do not condition the battery or give shorter charge times – EV batteries have their own BMS that is designed to look after the battery along with their own thermal management.