Can I charge my tractor battery (it is currently not in the tractor) with one of those portable electric batteries that are commonly used to jump start engines and power small appliances? I would like to charge it up before putting it in the tractor this spring.

My "generator" has the black and red clamps...

Thank you for any help

You would be better off using a trickle charger to slowly charge the battery . Im not sure exactly what you are thinking of using but if its what I think it is they are not meant for mainting a charge just more for start up assistance when faced with a dead battery. I would be worried about using this type of device to charge a stored battery its seems to me there is a great risk of overcharging. Over charging can produce really nasty results.

I looked your model up and it does not appear to be a trickle. Check auto parts stores most carry a few different trickle chargers and they aren't overly expensive I paid lss than 30 bucks for mine from advance auto parts.