running a mover off car?

[puddle hoppers inc.]

hi, would it be possible to run my jockey wheel power mover off the car battery(using croc clips) whilst the car is running, or could this damage alternator taking too much power out? just to save using the juice out of the caravan leisure battery you see, thanks, mike.

[Lazy-Ferret]

That should be fine, as they generally do not draw more power than the alternator is capable of delivering anyway.

The only real problem for an alternator is when you not only connect a flat battery across it, but then try to also draw the huge currents needed by starter motors.

[rustic]

You need to consider the size of the cable, as there will be a large voltage drop.

Unfortunately it's not a simple case of double the distance... double the cable size.
More like 2x2 the cable size. Using the square law.

If you have less volts at the motor, it could stall, draw a large current and burn out, so you will need to calculate the cable size etc. The manufacturer should be able to advise on cable size based on length.

Better to keep the battery local to the motor and have a heavy duty feed from the car to the battery, however this may not be practical.

EDIT...
A second battery in the back of the car might help. Short cables, but wired up to the main car system using a split charger with suitable cables.


Either way, You will need some heavy duty connectors, similar to what the AA/RAC use and electric fork lift trucks.

hope this helps,

best regards,
Rustic

[puddle hoppers inc.]

thanks for replies guys :thumb2
its got pretty good thickness cable already, and i can back the van into most places most of the time, its just the final adjustment i need to do so i can access the rear garden gate, so the cable is about 8 to 10 feet,which should do.
thanks again, mike.

[Lazy-Ferret]

He will only need to worry about additional voltage drop if he needs to extend the cables, not if he is just connecting it to the car battery via croc clips as he said.

IIRC , when I had my Big foot ET jockey wheel motor mover, it must have drawn less than 30 amps, as it had a "Green in-line spade fuse", and had a 3 or 4 meter lead.

My caravan is forward in the drive way, and tucked right up against the fence, so I could not get actually get to the caravan battery box to connect to that, so I used one of those 12 volt Powerpack/starter boxes to run mine. It easily had enough power to run the van backwards and forwards about 15 feet on the drive 3 or 4 times, to manoeuvre it away from the fence, and then drive it out onto the road up a small ramp about 40 feet. I then used to take it off, and put the jockey wheel back on, after reversing the car onto the van, as on my caravan, the jockey wheel is so far forward on the A frame, the handle of the motor mover hit the car before the hitches were aligned.

The only real thing was, it took so long to put it on, and take it off, and then when we had the new impressed concrete drive installed, we ended up selling it, as the slightest bit of damp on the shiny concrete, and it would not grip.