brunnhilde said no to trailer winch battery - part 5

 

I continued the work to get the trailer winch power supply project wrapped up, by routing the much more flexible 10 AWG wire pair down to the trailer hitch, and finished with an Anderson connector.

keeping up the proper workmanship so it look professional

the cable shielding will protect the wire against rodents

the harness is secured to the tow hitch and only get connected to the trailer's winch when being used

tidied up the cables with cable ties

Since my mind have been on the energy (battery charge) that is required to lift a car from the pavement onto the trailer, I decided to find the fun facts of potential energy. That is under ideal conditions when there are no energy loss from frictions and heat.

For a relatively light car it only takes 2.72 watt hour. Assuming the winching can be done in two minutes what would the amperage needs to accomplish it?

Using 12V nominal voltage that works out to 2.72 * 60 / 2 / 12 = 5.416A

The actual fact is I have seen around 30A on the amp meter but I don't know what the battery voltage were. I know it was a lot lower than 12.0V. Also I was winching it up a slope surface in addition to the loading ramp. It is no surprise a typical winch has a lot of energy loss due to the gearing and bearing friction, and the DC motor inefficiency. Additionally the friction from the car's wheels, brakes, and bearing and differential all add up to substantial drag.

I would use 25A as a ball park number if the battery voltage does not sag excessively. That is about a 5 times energy required due to all losses.