KNACRO DC 24V to DC 13.8V 40A 552W Converter Voltage Regulator 40A Step-up Power Supply Circuit Module Adapter for Auto Car Truck Vehicle Boat Solar System Electric Motor

Wiring: INPUT+ to BAT+, INPUT- to BAT-, OUTPUT+ to LOAD+, OUTPUT- to LOAD-
Reminder: Never reverse the polarity. Use the enough big cable to avoid the voltage drop. Never connect to solar panel or wind turbine. Never charge the battery.

Efficiency: 95%
Input Voltage: DC 24V (18-36V)
Output Voltage: DC 13.8V
Output Current: 40A
Ripple: 130mVp
Line Regulation: ± 0.2 %
Load Regulation: ± 0.2 %
Voltage Accuracy: ± 1.5 %
Enclosures: IP67
Dimension: 100*80*40mm
Net Weight: 0.5 kg
Case Operating Temperature: -40~85°C

Warranty: 1 year
MTBF: 100, 000 hours
Application:
24V DC battery of vehicles as input power to 13.8V DC appliances as output load.
Questions
How to choose the correct current for loads?
For example, if the max current of your load device is 10A, then choose 10A/ 0.8 = 12.5A at least for resistive loads according to international standard.
If the load device is motor or compressor, then you may choose 10A/ 0.5 =20A according to real testing result since the motor and compressor starting current may be 2-3 times than nominal current.