If you only have one dead battery in your truck it is possible to jump just that bad battery just like you would in a car. However in most cases, both batteries will be dead and you will need two 12 v batteries and two sets of jumpers to get the job done.. or you can put the two outside batteries in series on the ground and jump them as a pair to the pair in the truck with one set of cables..Be sure to hook up the ones in the truck first as there is where the H2 gas will be and you do not want to go kaboom. Wear safety glasses and hook up the negative on the jumper last. Best method is to do it thru the Slave cable receptical with a Military Jumper from another MV. Lastly, you can use 2 12 V battery chargers, one on each battery in your box for a couple of hours. Be really careful with sparks in this situation as there will be double amounts of H2 ....generated in this scenario And finally, my method is to buy two new batteries any time I have a problem with low voltage and then you can use the old batteries in the Mother in Law's car or recycle them for 11 cents a pound.