DCDC converter

I use a Converter, for using energy from 18650 4s 16.8 V batteries - - - 12.7 V for a 220 v inverter, for simply charging a car battery, for a touristic light.
the Converter has been tested without additional cooling, it works stably at a load of 10-13 A, but I live in Siberia, we are not hot.

spare parts i bought here

300W 20A Power Step Down Voltage Module DC-DC Buck Converter Module --- http://ali.pub/4fopd4
XT60 Male Female Bullet Connectors Plug --- http://ali.pub/4f9o1w

my inverter 12-220v has been working steadily for 4 years

2000W 1000W 500W Vehicle Car Power Inverter Converter DC 12V to AC 220V USB--- http://ali.pub/4forax