Here are some recommendations for best cart pen with faster heating speeds, along with their features:

1. Haier EC6003HD-BK3PROKAU1 (Little Magic Box BK3PRO): This model features an ultra-thin double-tank flat barrel design with a body length of only 70cm, making it ideal for installation in compact bathrooms. It has comprehensive upgrades in the inner tank, heating rod, and water quality health. Notably, the heating rod has been upgraded from a molybdenum gold heating rod to a new generation of zirconium gold all-ceramic heating rod, which significantly improves heating efficiency and performance.

2. Haier EC6005-JE7KU1: This model has an upgraded heating performance with 3.3KW/3KW dual-tube variable frequency fast heating, coupled with 9 times dynamic capacity expansion, ensuring you won't run out of hot water. It features 3D Smart Wash technology, with a 3D energy ring around the water outlet that can instantly increase the water temperature by 15°C when the water flows out, providing hot water immediately, saving time and electricity.

3. Casarte CEC6005-CJ7U1: This flagship model from Casarte features a titanium gold seamless double tank, with a 3KW heating system configured for both the upper and lower tanks, along with 13 times dynamic capacity expansion, ensuring ample hot water even when using a large showerhead or bathtub. Its screen has also been upgraded to a wide-screen design, with the width increased by about twice, allowing real-time viewing of remaining hot water and water quality monitoring results on the screen, providing more peace of mind.

These best cart pen offer faster heating capabilities and can meet your needs for best cart pen with quicker heating speeds. When choosing, you can decide on the most suitable product based on specific usage scenarios and budget.