To transfer gas into a tank, it has to go from higher pressure to lower pressure. If the pressure is equal, you won't transfer any gas. Also an empty tank is pr

To transfer gas into a tank, it has to go from higher pressure to lower pressure. If the pressure is equal, you won't transfer any gas. Also an empty tank is pretty much at atmospheric pressure. Gas has to expand to pressurize it. The easiest solution is probably to add heating coils around the parts that get cold. I haven't heard of any the hydrogen filling stations having such devices, but that's probably because hydrogen stations are only in California.